DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
DIVISION 15
MECHANICAL SYSTEMS
Division 15 of the Carnegie Mellon University Design and Construction Standards
Manual addresses the following requirements for mechanical construction:
15010
15050
15100
15135
15140
15170
15250
15330
15410
15430
15440
15453
15460
15481
15488
15510
15520
15530
15540
15545
15582
15680
15683
15685
15711
15755
15781
BASIC MECHANICAL REQUIREMENTS
BASIC MECHANICAL MATERIALS AND METHODS
VALVES
METERS AND GAGES
SUPPORTS AND ANCHORS
MOTORS AND DRIVES
INSULATION
FIRE SUPPRESSION SYSTEMS
PLUMBING PIPING
PLUMBING SPECIALTIES
PLUMBING FIXTURES
PUMPS
WATER HEATERS
COMPRESSED AIR SYSTEMS
NATURAL GAS SYSTEMS
HYDRONIC PIPING
STEAM AND STEAM CONDENSATE PIPING
REFRIGERANT PIPING
HVAC PUMPS
CHEMICAL WATER TREATMENT
STEAM CONDENSATE RETURN UNITS
WATER CHILLERS
RECIPROCATING WATER CHILLER
WATER-COOLED CENTRIFUGAL CHILLERS
FACTORY-FABRICATED COOLING TOWERS
HEAT EXCHANGERS
PACKAGED HEATING AND COOLING AIR HANDLING UNITS
DIVISION 15
DESIGN AND CONSTRUCTION STANDARDS
MECHANICAL SYSTEMS
FACILITIES MANAGEMENT SERVICES
DIVISION 15 MECHANICAL SYSTEMS (CONT)
15782
15790
15831
15832
15835
15840
15850
15854
15860
15865
15870
15886
15891
15920
15930
15932
15970
15975
15985
15990
P. 15-2
ROOFTOP HEATING AND COOLING UNITS
AIR COILS
FAN COIL UNITS
FINNED-TUBE RADIATION
UNIT HEATERS
UNIT VENTILATORS
FANS AND EXHAUST SYSTEMS
CENTRAL STATION AIR HANDLING UNITS
CENTRIFUGAL FANS
TUBULAR CENTRIFIGALS
POWER VENTILATORS
AIR FILTERS
METAL DUCTWORK
SOUND ATTENUATORS
AIR TERMINALS
AIR OUTLETS AND INLETS
HVAC CONTROLS
CONTROL SYSTEM EQUIPMENT
SEQUENCE OF OPERATION
TESTING, ADJUSTING, AND BALANCING
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
15010 BASIC MECHANICAL REQUIREMENTS
The Design Consultant shall be expected to analyze a minimum of three alternative
systems and justify the selected system. For example: typically variable air volume
(VAV) systems are preferable to individual fan coil units because of reduced maintenance
requirements. Fan coil systems will be allowed in special circumstances such as where
ceiling space is limited, and there is adequate room for ductwork. As another example:
typically VAV systems are preferable to constant volume in fume-hood exhaust
applications, but one- or two-hood laboratories may not warrant the expense.
Mechanical Rooms
All mechanical equipment shall be located inside the building wherever possible. The
Design Consultant shall allow for adequate mechanical space during the programming
phase. (Architectural graphics standards shall be used as a guideline.)
Mechanical rooms shall be designed in accordance with all applicable codes.
Mechanical rooms shall be designed to provide adequate maintenance clearances for all
equipment (such as tube and coil pull spaces). Adequate means of access shall be
provided for replacement of the largest piece of equipment without removing walls.
Clearance shall be adequate to allow maintenance activity without disassembly of any
fixed piping, supports, and so forth. Clearance shall be provided around boilers and
pressure vessels in accordance with the Pennsylvania Boiler Code.
Mechanical rooms with heat-producing equipment shall be provided with an automatic
ventilation system.
Mechanical rooms shall be provided with a minimum of one floor drain. Floor drains
shall be piped to a sanitary system.
Mechanical rooms shall be provided with at least one hose bib with backflow preventer in
the supply piping.
All equipment drains, blowdown lines, and such shall be piped to a floor drain with an
approved air gap fitting. (See Section 15510 Hydronic Piping.)
Mechanical rooms shall be located to provide access directly from the building exterior.
Where this is not possible, mechanical rooms shall be accessed from public spaces.
Mechanical rooms shall not be located where vibration and/or noise will be objectionable.
Mechanical rooms shall be heated to maintain 55 °F minimum.
Janitor Rooms
Janitor rooms are not accessible to maintenance employees. Therefore, mechanical
equipment, valves, electric panels, thermostats, and so forth shall not to be placed in these
rooms.
December 1998
P. 15-3
DIVISION 15
DESIGN AND CONSTRUCTION STANDARDS
MECHANICAL SYSTEMS
FACILITIES MANAGEMENT SERVICES
Design Guidelines
The following are general design guidelines for inside and outdoor design conditions.
Design Guidelines for Indoor and Outdoor Temperatures
Area
Season
Indoor (Note 3)
Outdoor
Comfort Areas (Note 1)
Summer
76°F DB
91 °F DB, 72 °F WB
Winter
70°F DB
0 °F DB
Summer
Consult with User
91 °F DB, 72 °F WB
Winter
Consult with User
0 °F DB
Summer
As specified in latest edition
of “Guide for Care and Use of
Laboratory Animals”
95 °F DB, 75 °F WB
Winter
As specified in latest edition
of “Guide for Care and Use of
Laboratory Animals”
-10 °F DB
Labs & Critical Areas
Animal Rooms (Note 2)
Note 1 Consideration shall be given to morning warm-up cycle.
Note 2 Typically these systems are required to be 100% outdoor air systems, therefore, the outdoor design
conditions are altered for these and any other 100% outside air systems. Specified discharge air
temperatures shall be maintained at all times.
Note 3 Design conditions shall be scheduled on the Contract documents for each room. Rooms may be
grouped by number for simplicity of document preparation. Design conditions shall appear on the
first sheet of the heating, ventilating, and air-conditioning drawings, per the BOCA code.
Minimum and maximum relative humidity requirements shall be identified by the
Design Consultant in conjunction with the end user.
Energy Costs
Life Cycle Cost Analyses are required, or alternative system evaluations such as for
constant volume vs. variable volume hood exhaust systems and for any energy-saving
features incorporated into the project. Alternative system evaluations shall be required in
all moderate and complex projects, involving new mechanical systems.
Energy costs will be identified by the University and shall be used in all Life Cycle Cost
Analyses. As energy costs are modified from time to time, the Design Consultant shall
consult the University for the most recent revisions.
Design Calculations
The University requires a record copy of calculations for all projects to be submitted at
the end of Design Development.
P. 15-4
December 1998
DESIGN AND CONSTRUCTION STANDARDS
DIVISION 15
FACILITIES MANAGEMENT SERVICES
MECHANICAL SYSTEMS
Equipment (Non-Typical) Loads or Process Heat Gains
Equipment or process heat gains, excluding people, lights, conduction, and solar loads, in
critical and special areas such as computer rooms, microcomputer labs, and research labs
shall be scheduled on the drawings by room number for future reference.
General Pressure Relationship and Ventilation Requirements
The following table provides the pressure and ventilation requirements for University
buildings.
University Building Pressure and Ventilation Requirements
Area
Pressure
Relationship to
Adjacent Areas
Minimum Outdoor
Air Requirement
All Air Exhausted
to Outdoors
Recirculation
Permitted **
Animal Rooms
*
*
*
*
Auditoriums
E
Note 1
No
Yes
Classroom
E
Note 1
No
Yes
Computer Rooms
E
Note 1
No
Yes
Copy Centers
N
Note 1
Yes
No
Darkrooms
N
Note 1
Yes
No
Dining Areas
P
Note 1
No
Yes
Janitors Closets
N
Note 3
Yes
No
Kitchens
N
Note 1
Yes
No
Laboratories
Note 4
Note 1
Note 4
Note 4
Laundry
N
Note 1
Yes
No
Libraries
E
Note 1
No
Yes
Locker Areas
N
Note 1
Yes
No
Lounges
N
Note 1
No
Yes
Mech/Elect Room
N
Note 2
Yes
No
Music Rooms
E
Note 1
No
Yes
Offices
E
Note 1
No
Yes
PC Labs
E
Note 1
No
Yes
Toilet Rooms
N
Note 3
Yes
*
Refer to “Guide for Care and Use of Laboratory Animals”
**
Does not apply to units serving this area only. The air may be recirculated by roof units.
P,E,N= Positive, Equal, Negative
No
Note 1 Conform to ASHRAE STANDARD 62, Ventilation for Acceptable Air Quality (latest edition) and Mechanical
Ventilation, BOCA, latest edition.
Note 2 Quantity required to maintain a maximum of 10 °F above Summer Outdoor Design DB temperatures.
Note 3 Transfer from corridors permitted when allowed by code. Exhaust air quantity shall be greater of 2.5 cfm/ft 2 or
10 air changes per hour (AC/HR).
Note 4 Review specific requirements with the University Project Manager and the University EH&S Office.
Requirements may vary.
December 1998
P. 15-5
DIVISION 15
MECHANICAL SYSTEMS
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
Central Chilled Water
The chiller run-around pumps are constant volume, decoupled from the distribution loop,
and as load is added to the system, the load is decoupled from the distribution loop via a
“primary/secondary” piping bridge. The distribution loop is sized for a 15 °F water
temperature drop and served by variable-speed pumps. Load side pumps are typically
constant volume, but variable-speed pumps may be warranted in some cases.
Zoning
Zoning of the systems shall be in accordance with sound engineering judgment relating to
varying load conditions, function of space, occupancy schedules, and such. Final zoning
shall be discussed at the conceptual design stage with the University Project Manager.
All-Air Systems
Ducted supply and return systems are required. Return plenums are not permitted without
prior approval.
100% shutoff variable air volume systems are not permitted. Minimum airflow must be
maintained to satisfy ventilation requirements. Reheat shall be provided for all interior
zone VAV boxes where there is potential for no internal load (such as conference rooms).
Fan powered boxes using re-circulated air may be considered as a last resort.
Economizer cycle (see Section 15985) shall be utilized on all systems over 2000 cfm
(with the exception of computer rooms or other rooms with strict RH requirements) for
areas requiring year-round cooling.
For all systems 5 tons and over that use economizer cycles, a separate return or exhaust
fan shall be used to provide positive relief.
The requirement for duct air leakage tests shall be reviewed on a project basis with the
University Project Manager.
Standby Equipment for Critical Areas
Standby equipment requirements shall be discussed with the University Project Manager
for systems serving critical areas such as:
• Laboratories
• Research buildings
• Animal rooms
Contract documents shall indicate equipment that is intended for standby service.
Animal rooms, in addition to being tied into the main building’s chilled water system,
shall have an alternate connection to city water for emergency use.
Auto changeover shall be provided for all standby equipment. Changeover shall be
alarmed to the direct digital control (DDC) system.
P. 15-6
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
Equipment Locations
Terminal units and air handling equipment shall not be located above an occupied space
without prior approval from the University. All equipment must be readily accessible for
maintenance. Equipment located 4 ft or more above the finished floor level shall include
access platforms or walkways.
Floor-mounted HVAC equipment (including specialty laboratory equipment such as
nuclear magnetic resonators (NMRs) shall be installed on concrete housekeeping pads.
Pads shall be isolated from the surrounding slab if vibration requirements warrant.
All equipment installed on grade outdoors shall be installed on reinforced concrete pads.
Foundation requirements shall be analyzed for large pad-mounted equipment.
Locations of mechanical equipment that affects the aesthetics of a building or the campus
shall be approved by the University Architect. Approval procedures shall be discussed
with the University Project Manager.
Identification
All motor-driven equipment shall be individually numbered on the drawings by the
Design Consultant (for example, unit heaters may be numbered UH-1, UH-2, etc., even
though both units may be the same size and type). Numbers shall be in accordance with
the University’s Preventative Maintenance database numbering guidelines. Where
possible, numeric sequence shall follow the last number for each building. The University
Project Manager will obtain this information for the Design Consultant from the
Preventative Maintenance Manager.
All motor-driven equipment, including associated electrical devices, shall be tagged in
accordance with the University’s Preventative Maintenance numbering guidelines. Tags
shall be engraved, black, laminated, micarta tags with white-reading symbols secured to
equipment (not the motor), usually inside the access door for the equipment in finished
areas and exposed in all other areas. Tags should be sized to include the University
barcode label (2.5-in. x 1.0-in.), mechanically fastened to the equipment. GLUE OR
WIRE IS PROHIBITED. Where possible, numeric sequence shall follow the last number
in that building. The University Project Manager will obtain this information from the
Preventative Maintenance Manager for the Design Consultant.
Condensing Units and Condensers
The manufacturer’s minimum recommended clearances, including distances from
landscaping, shall be maintained.
Where water-cooled condensing units are specified, cooling towers, evaporative
condensers, or a central chilled water system shall be used. Cooling water to waste system
is NOT permitted.
December 1998
P. 15-7
DIVISION 15
MECHANICAL SYSTEMS
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
Packaged Heat Pumps
Use of air-cooled packaged heat pumps on the University campus is not permitted.
Potential water-cooled applications shall be reviewed with the University Project
Manager.
Sound Pressure Level Requirements
The sound pressure levels around mechanical and electrical equipment (boilers, fans,
pumps, pressure-reducing valves, motors, turbines, elevators, transformers, etc.) in
equipment spaces shall not exceed 85 dBA at any point 3 ft from the equipment, with all
equipment in the room operating. Sound calculations shall be required. The sound
criterion applies to the complete operating range of each piece of equipment. Exceptions
shall be reviewed by the University Project Manager.
The maximum room criteria (RC) levels for various usage within the building shall be as
indicated in Table 2, Design Guidelines for HVAC System Noise in Unoccupied Spaces,
Chapter 43, “Sound and Vibration Control,” of the latest edition of the ASHRAE Systems
and Applications Handbook.
Sound pressure level measurements shall be made in accordance with “Sound Testing
Procedures” outlined in the latest edition of the ASHRAE Systems and Applications
Handbook. Tests shall be made with all equipment operating, and space unoccupied.
Equipment installed outside the building, at grade, in areaways, attached to walls, and on
the roof, such as cooling tower fans, air conditioning units, refrigerant condensers, fans,
exhaust silencers, air intakes, etc., shall comply with all local, city, state, and federal
sound level regulations (as well as any existing University covenants or agreements with
neighbors).
When equipment or space sound pressure levels exceed the specified criteria, the
Contractor and/or the Design Consultant shall, at no cost to the University, determine the
source of the noise and make the necessary corrections to reduce it to the acceptable
levels.
Guarantee
The specifications shall be prepared to include a one-year labor and material guarantee for
the entire installation, with the exception of extended guarantee periods for the following:
• Refrigeration Compressors - Five years
• Automatic Temperature Control (ATC) Systems - Two years
P. 15-8
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
15050 BASIC MECHANICAL MATERIALS AND METHODS
Ceiling Access Panels
Screwdriver-actuated locks are required on ceiling access panels.
Access panels are not required in lift-out ceilings, but each panel must be identified with
a color button, cleated through. The color code of the principal service shall be used.
Access panel sizes shall be suitable for application.
Access panel locations and sizes shall be indicted on Contract drawings.
15100 VALVES
General
All valves of a particular type and size range on any one project shall be the product of
one manufacturer.
Valves shall be right handed.
Small balancing cocks shall be the type that can be used for shut-off without disturbing
the balancing point setting.
Where possible, valves shall be installed with the valve bonnet in an upright position to
prevent deterioration or corrosion of the bonnet and packing.
Valve body materials shall be compatible with piping system materials.
A valve drain shall be provided at the base of each water piping riser and manual air vents
shall be provided at the top of each riser and at the high point of the system.
All valve, strainers, and steam traps shall be provided with reusable strap-on insulation
covers.
Valve tags shall be 1- x 2-in. laminated, black micarta attached by a 10-gage brass “S”
hook. Valve numbers shall be engraved as large as possible and shall read white. Where
possible, the numbering sequence shall follow the last number used in that building.
Valve charts shall be typewritten on white bond paper and mounted in a glass front frame.
Charts shall indicate service, number, and location.
On renovation projects, the Contractor shall be directed to revise existing valve charts as
required.
All exposed valves in finished areas shall be chrome-plated.
Ball Valves
All branch lines in the water supply piping up to 3-in. in diameter shall be fitted with ball
valves. Ball valves shall also be used for sectioning the water distribution system. Where
insulation is required, extended stems shall be provided.
December 1998
P. 15-9
DIVISION 15
MECHANICAL SYSTEMS
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
Butterfly Valves
Butterfly valves are acceptable for shut-off service and balancing and should be used on
piping 2-in. in diameter and greater. (For branch lines over 3-in. in diameter see “Ball
Valves.”)
Gate Valves
A gate valve, angle valve, or compression stop shall be placed immediately below each
plumbing fixture on each hot and cold supply so that service can be readily shut off for
maintenance.
Pump Valves
All circulating pumps shall have a check valve and a balancing valve on discharge. In lieu
of this, in-line triple-duty valves are acceptable.
Shutoff Valve
Isolation shutoff valves shall be installed at each piece of equipment, terminal unit, and
each branch takeoff to facilitate shutdown for repair. Positive shutoff balancing valves
with memory may satisfy this requirement at terminal units.
Balancing Valves
Balancing valves shall be installed in all three-way control valve bypass lines and at all
flow meters.
Gate valves shall NOT be used in a throttling application. Globe plug valves or ball
valves shall be used. Gate valves shall be limited to shutoff service only.
Where balancing valves are installed, there shall be some means (not including Pete’s
Plugs) to read flow.
Circuit setters shall be used on pipe less than 2-in. in diameter.
Check Valves
Where check valves are required, they shall be installed on the equipment side of all
shutoff valves to facilitate servicing of the check valve.
Drain Valves
Drain valves shall be a minimum diameter of 0.75 in. with hose end connection and cap.
Control Valves
The design documents shall include a valve schedule for all ATC valves. The schedule
shall indicate service, flow, CV, and pressure drop.
P. 15-10
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
15135 METERS AND GAGES
Gages
Differential pressure gages shall be provided across the supply and return of water meters,
water filters, coils, and pressure reducing valves (PRVs). “PT” Pete’s Plugs may be used
on reheats.
Thermometers shall be provided on supply and return of water coils, chiller tube bundles,
heat exchangers, boilers and reheats.
Regardless of whether the control system is pneumatic or DDC, dial thermometers shall
be placed on all air handler system discharge, return, mixed air, and outside air ductwork.
The location of dial thermometers shall be shown on plans.
Normal Use
Gages shall have screw-type recalibration, bronze bushed movements, quality unit
construction, and 4.5-in. dial. The Plumbing Contractor shall provide similar gages for
water and air. Gages shall be calibrated for static head. All gages shall be equipped with
shutoff valves and snubbers. Gages located overhead shall have a 6-in. diameter, and
shall be positioned so that they are readable from floor level.
Siphons shall be used with all steam gages. Also, all gages shall have snubbers and gage
cocks or isolation valves suitable for the pressure involved.
Thermometers for general use shall be RED “V” series as manufactured by Marshalltown
Manufacturing, Incorporated. Remote-reading Model V-7 vapor tension and bulb shall be
used and mounted in panelboards where possible. When the above is not possible or
practical, the Model V-3 with three-way mounting bracket shall be used. Field
thermometers on an air handler shall include discharge air, return air, outside air, and
mixed air. Field thermometers on water lines shall be “tree” type.
Gages and thermometers shall be read to twice the operating pressure or temperature
including static head for water. The Design Consultant shall specify gage and
thermometer ranges.
15140 SUPPORTS AND ANCHORS
Pipe Hangers and Supports
An adequate pipe suspension system shall be designed and installed in accordance with
recognized engineering practices, using standard, commercially accepted pipe hangers
and accessories. The use of pipe hooks, chains, or perforated iron for pipe supports is not
acceptable.
Pipe suspension systems for fire suppression systems shall be designed and installed in
conformance with applicable sections of BOCA and NFPA.
December 1998
P. 15-11
DIVISION 15
MECHANICAL SYSTEMS
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
The Contractor shall submit data sheets for approval on all pipe hanger items prior to
installation.
All piping shall be arranged to maintain the required pitch and shall provide for proper
expansion and contraction.
No holes shall be drilled or burned in structural building steel for hanger rod supports.
Vertical runs of pipe shall be supported with riser clamps made specifically for pipe or for
tubing.
Hanger rods shall be threaded 1.5 in. on each end or continuous thread. Eye rods shall be
welded. The minimum diameter shall be no less than 0.375-in. for support of pipe with a
2-in. diameter or smaller, or 0.5-in. for support of pipe with a 2.5-in. diameter or larger
(per ANSI/ASME B31.1 Power Piping Code).
Supports for plastic and copper piping shall be spaced at a maximum of 6 ft on center.
For steel pipe, the maximum spacing of supports shall be per Table 121.1.4 of
ANSI/ASME B31.1 Power Piping Code.
Where there are concentrations of valves and fittings, closer spacing may be necessary.
Hangers shall be installed not more than 12 in. from each change in direction of pipes.
All hangers for piping shall have a means of vertical adjustment. If adjustment is not
incorporated in the hangers, turnbuckles are acceptable.
Piping suspension systems with vibration isolation capability shall be provided as
required. More information on vibration isolation requirements for piping suspension
systems is provided in Resilient Pipe Hangers, Page 38, Chapter 43, “Sound and
Vibration Control,” of the latest edition of the ASHRAE Systems and Applications
Handbook.
Copper clamps and hangers shall be used on copper piping.
Pipe Expansion
The Design Consultant shall examine the piping system and shall design expansion
compensation into the system by use of expansion loops, flexible connectors or, where
space is limited, self-aligning bellows-type expansion joints.
The Design Consultant shall design all anchors and guide supports as needed and shall
detail them on the drawings.
Vibration Control
Mechanical and electrical equipment and associated piping and duct work shall be
mounted by vibration isolators as specified and as required to minimize transmission of
vibrations and noise to building structures or spaces. Selection of isolator type shall be as
given in Table 41, Equipment Vibration Criteria, Chapter 43, “Sound and Vibration
Control,” of the latest edition of the ASHRAE Systems and Applications Handbook.
P. 15-12
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
All rotating equipment shall be balanced both statically and dynamically. Vibration shall
not exceed the guidelines given in Table 41, Equipment Vibration Criteria, Chapter 43,
“Sound and Vibration Control,” of the latest edition of the ASHRAE Systems and
Applications Handbook.
All motors over 5 hp must be solidly attached to a common base with the driven unit to
minimize alignment problems. Solid sheaves and band belts shall be used to minimize
vibration in multiple V-belt driven equipment over 15 hp.
Vibration analysis shall be conducted by the Contractor in the presence of the University
representative and the Design Consultant. The Contractor shall furnish, at no cost to the
University, qualified personnel and all instrumentation to conduct the analysis. The
Contractor shall remove housings and covers and dismantle equipment as required to take
vibration readings. After readings have been completed, the Contractor shall reassemble
all equipment.
It shall be necessary to check only equipment that, in the opinion of the University and
the Design Consultant, does not meet the specification requirements.
Where equipment vibration exceeds levels specified, the Contractor shall be directed to
make corrections to reduce vibration frequencies and amplitude to within specified limits.
If this cannot be accomplished, the equipment shall be replaced with equipment that will
meet all requirements of the specifications at no cost to the University.
The Contractor shall submit a report for approval to the University and the Design
Consultant. The report shall include the vibration analysis of all rotating equipment of 0.5
hp and larger.
Isolation Equipment
Isolation shall be stable during starting and stopping of equipment without any transverse
and eccentric movement of equipment that would damage or adversely affect operation of
the equipment or appurtenances.
Isolation shall be selected for the operating speed of the equipment.
Isolators, including springs, exposed to the weather shall be hot dipped galvanized after
fabrication. Hot dipped zinc coating shall comply with ASTM Method A-123 and shall
not be less than 2 oz per square foot.
Isolators shall be selected and located to produce uniform loading and deflection even
when equipment weight is not evenly distributed.
The type of isolation, base, and minimum static deflection shall be as required for each
specific equipment application when supported on a solid (150 lb/ft3) concrete structural
slab having a thickness of not less than 6 in. If vibration isolators with a deflection greater
than the minimum specified are required to meet the noise criteria for the adjacent spaces,
suitable isolation systems shall be submitted for approval prior to installation.
Should vibration isolators installed for the equipment prove inadequate to prevent
transmission of equipment vibrations to the building structure or limit equipment
December 1998
P. 15-13
DIVISION 15
MECHANICAL SYSTEMS
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
vibration noise in the building spaces to their specified noise criteria levels, the isolators
shall be replaced with units having the largest deflection that can be practically installed
at no additional cost to the University.
Piping and Ductwork
Vibration isolation shall be provided for the following:
• All high-pressure ducts (over 6 in. wc), for 20 ft from air handling equipment
mounted on vibration isolators
• All piping connected to equipment mounted on vibration isolators for a distance of
20 ft or 50 pipe diameters, whichever is longer
• All piping connected to pumps, including the main supply and return risers, for 20 ft
from the branch connection at each floor
Vibration isolation shall be provided where there are flexible connections between
equipment and ductwork.
Hanger vibration isolators shall be selected for not less than the deflection provided for
the equipment to which the piping is connected. The vibration isolator units selected shall
provide for the thermal movement of the piping systems. Spring hanger isolators shall be
substituted for elastometric type supports when their permissible hanger rod angular
deflection will be exceeded.
15170 MOTORS AND DRIVES
For requirements related to motors and drives, contact the University Project Manager.
15250 INSULATION
Insulation shall be applied on clean, dry surfaces and only after tests and approvals
required by the specifications have been completed.
All pipe insulation on piping operating below ambient temperature shall be continuous
through wall and ceiling openings and sleeves.
Insulation on all cold surfaces must be applied with a continuous, unbroken vapor seal.
Hangers, supports, anchors, etc., that are secured directly to cold surfaces shall be
adequately insulated and vapor sealed to prevent condensation.
Specified adhesives, mastics, and coatings shall be applied at the manufacturer’s
recommended minimum coverage per gallon.
Edges of vapor barrier insulation at valve stems, instrument wells, unions, and other raw
edges shall be sealed adequately to prevent moisture from penetrating the insulation.
P. 15-14
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
Fire Hazard Ratings
All insulation shall have composite (insulation jacket and adhesive used to adhere the
jacket to the insulation) Fire and Smoke Hazard ratings as tested under procedure ASTM
E 84, NFPA 225, and UL 723.
Insulation Protection Shields
Insulation protection shields shall be installed at all pipe hangers and supports. Shields
shall span an arc of 180°.
An 18-gage stainless steel shield shall be installed fully over all insulated piping located
on the roof. The shield shall be a minimum length of 36 in. and field located to prevent
damage to the insulation while walking over the piping.
Within mechanical equipment rooms (MERs), all piping below 7 ft shall have insulation
jacketing of PVC. In steam tunnels, an aluminum jacket shall be used; above ceilings, a
standard all-service fiberglass (ASF) jacket shall be used.
Duct Insulation
Insulation systems shall conform to the requirements in the Commonwealth of
Pennsylvania Act 1980-222.
The use of duct liner is discouraged. Duct liner may be considered for acoustical purposes
only. Special sound attenuators shall be used wherever required to eliminate fan noise.
The University representative shall be contacted for approval.
All duct insulation in mechanical rooms shall be rigid fiberglass board, with a minimum
density of 6 lb/ft3. All other duct insulation shall be blanket type.
Pipe Insulation
Insulation systems shall conform to requirements in the Commonwealth of Pennsylvania
Act 1980-222.
In general, piping systems shall be insulated with fiberglass piping insulation with an allpurpose jacket. Fittings, flanges, and valves shall be insulated with fiberglass inserts and
premolded polyvinyl or PVC jackets.
Refrigerant piping systems shall be insulated with elastromeric pipe insulation.
Calcium silicate or high-temperature fiberglass shall be used in steam applications.
Special insulation protection shall be considered for areas subject to abuse and moisture,
such as outside areas, washdown areas, public areas, and classrooms.
Removable insulated jackets shall be provided on all valves.
The following equipment shall be provided with insulation:
• Air eliminators
• Boilers
December 1998
P. 15-15
DIVISION 15
MECHANICAL SYSTEMS
•
•
•
•
•
•
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
Chilled water pump bodies
Hot water storage tanks
Heat exchangers
Cold surfaces of chillers
Flue pipe
Engine exhaust
15330 FIRE SUPPRESSION SYSTEMS
Fire suppression systems shall be provided per BOCA code, unless exempted by local
code. A fire standpipe protection for buildings during construction shall be referenced to
the requirements of the code, the fire department, and/or the underwriters, Factory
Mutual.
Submittals and Approvals
All devices and equipment installed in the systems shall be approved and listed by
Underwriters Laboratories and/or Factory Mutual.
The Design Consultant should make early contact with the University’s Fire Safety
Specialist (in the University EH&S Office).
Prior to final approvals by the University, the Design Consultant shall submit plans and
specifications to the insurer for approval. These approvals shall then be submitted to the
University.
The Contractor’s final shop drawings and specifications shall be submitted to United
States Fidelity and Guaranty Company (USF&G) for approval prior to submittal to the
University Architect for approval.
All projects involving street-pressure sprinkler systems, street-pressure fire standpipe
systems, or fire pumps require hydrant tests on the mains in all streets that can be used to
feed the building. The University will provide flow test data on request.
All sprinkler lines shall be equipped with an inspector’s test connection piped directly
into a drain capable of handling discharge from a fully-opened test valve.
Materials
All control valves shall be of butterfly indicator type or outside stem and yoke (OS&Y)
type.
P. 15-16
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
15410 PLUMBING PIPING
Piping shall be pitched and valves installed to facilitate complete drainage of the system.
All piping run within the building shall be concealed in the finished portions of the
building in pipe spaces, ceilings, or furred chases and exposed only in mechanical rooms
and where shown on the drawings.
No pipe shall pass in front of or interfere with any openings, doors, or windows.
Headroom in front of openings and doors shall in no case be less than the top of the
opening. No pipe shall pass in front of or interfere with clearances around mechanical
equipment.
Piping shall not pass exposed through electrical rooms or be erected over any switchboard
or other electrical gear (except as may be required by local code for fire suppression).
Pipe sizes shall be indicated on the plans at each change in direction and at all branch
take-off locations.
Two-in. clearance shall be provided between insulated piping and other obstructions.
No union shall be placed in a location that will be inaccessible. Unions shall be installed
adjacent to all equipment for repair and replacement.
Flexible piping connections shall be provided at piping connections to all rotating
mechanical equipment, and at piping connections to all equipment mounted on vibration
isolators. Connectors shall have a pressure rating suitable for the piping systems in which
they are installed.
Dielectric unions shall be provided between dissimilar materials for electrolysis control.
Bypasses
Bypasses shall be installed around water meters, control valves, and pressure-reducing
stations serving critical areas (to be reviewed with the University Project Manager). Ball
or butterfly valves shall be used.
No other equipment is to be provided with a bypass unless approved by the University
Project Manager.
Sleeves
All pipes passing through masonry construction shall be fitted with sleeves. Each sleeve
shall extend through its respective floor, wall, or partition and shall be cut flush with each
wall surface unless otherwise specified. Sleeves shall be two pipe sizes larger than the
pipe when un-insulated and of sufficient size to allow for the insulation without binding.
Floor sleeves in mechanical rooms shall extend 4 in. above the finished floor; for all other
spaces, the floor sleeves shall be a minimum 1 in. above the finished floor.
Sleeves in load-bearing and masonry walls, floors, and partitions shall be standard weight
steel pipe finished with smooth edges. For other than masonry partitions, through
suspended ceilings, and for concealed vertical piping, sleeves shall be No. 22 USG
December 1998
P. 15-17
DIVISION 15
DESIGN AND CONSTRUCTION STANDARDS
MECHANICAL SYSTEMS
FACILITIES MANAGEMENT SERVICES
galvanized steel. No sleeve is required where an opening is core-drilled through concrete
floors or ceilings.
Space between sleeves and pipes shall be filled with fireproofing material and caulked.
Where pipes pass through waterproofed floors or walls, the design of the sleeves shall be
such that waterproofing can be flashed into and around the sleeves.
Sleeves through exterior walls below grade shall have the space between pipes and
sleeves caulked watertight or fitted with a “link-seal.”
One-piece chrome-plated escutcheon plates shall be installed with setscrews at sleeves for
all pipes exposed in finished areas.
Where pipes pass through fire-rated partitions, the annular space around the pipes shall be
sealed and/or filled with fireproofing sealers.
System and Equipment Drains
All piping shall be arranged to completely drain the system. Drain locations shall be
indicated on the drawings.
Where sectionalizing valves are installed, a drain shall be installed on the downstream
side of the valve to drain that section of the system.
All cooling tower drains and overflow shall be piped to a sanitary system (not onto the
roof).
All system and equipment drains and air vents shall be piped to a floor drain.
Welding
All welding shall be done in accordance with the American Welding Society (AWS).
All boiler, pressure vessel, and gas piping welding must be done by certified welders.
Pressure Tests
All piping must be tested prior to receiving insulation.
Prior to filling the systems, all joints and potential leak sources shall be painted with a
water-power blue line caulk mixture and allowed to dry.
During the test, each joint shall be inspected visually.
Test pressures shall be a minimum 1.5 times system operating pressure or as specified by
the Design Consultant.
Pressure tests shall be witnessed by a University representative.
P. 15-18
December 1998
DESIGN AND CONSTRUCTION STANDARDS
DIVISION 15
FACILITIES MANAGEMENT SERVICES
MECHANICAL SYSTEMS
Identification
Three-fourth in. wide, adhesive-backed vinyl cloth labels shall be used on all piping 2 in.
and smaller. Label lettering shall identify both the medium being conveyed and the
direction of the flow.
Labels shall be spaced on maximum 15-ft centers, as well as at branch take-offs, and on
either side of wall penetrations. Labels shall be positioned for easy viewing.
Identification Symbols and Colors for Plumbing Piping
Service
Symbol
Field Color
Service
Symbol
Field Color
Fire line
Fire
Red
Domestic hot water
return
SCWS
Green
Sprinkler line
Spr.
Red
Deionized water supply
DI
Green
Sanitary waste
SW
Blue
Drinking water supply
DWS
Green
Sanitary vent
SV
Blue
Drinking water return
DWR
Green
Soil stack
San. S.
Blue
Gas
Gas
Yellow
Soil vent
San V.
Blue
Vacuum
Vac.
Gray
Down spout
Rain
Blue
Compressed air
(laboratory)
Air
Brown
Domestic cold water
supply
CWS
Light brown
Compressed air
Air
Dark blue
Domestic hot water
supply
HWS
Dark brown
Soil, Waste, and Vent Piping
Cast Iron
Cast iron soil pipe and fittings shall be service weight with hub and spigot conforming to
ASTM A-74 and ANSI A112.5.1. Having no hub is also acceptable.
Cast iron soil pipe shall be supported every 5 ft and at every joint. Hangers shall also be
installed at branch locations and where lines change directions. Stacks and risers shall be
supported at the base by concrete piers and by riser clamps at floor level.
Joints shall be made with neoprene, compression-type gaskets conforming to ASTM
C564.
The University prefers neoprene vent roof flashing with stainless steel damps.
PVC or CPVC piping shall be used for fused joints and drainage water vent (DWV)
fittings.
Galvanized Steel
Waste lines from kitchens, laundries, and other areas where very hot water is used shall
be Schedule 40, galvanized ASTM A 53 piping with cast iron drainage fittings.
December 1998
P. 15-19
DIVISION 15
MECHANICAL SYSTEMS
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
Acid Waste Lines (Under Floor/Under Ground to First Manhole)
Acid-resistant underground waste and vent lines shall be cast iron hub and spigot alloyed
with approximately 14% silicon and shall conform to ASTM D651-48. Piping shall be
Durion or equal.
Joints in acid-resisting pipe shall be made with caulking lead conforming to ASTM B 29.
The need for acid-neutralizing sumps will be determined by the pH of the discharge.
Measurements below the acceptable range set by the local sewage authority shall dictate
the need for acid neutralization.
Acid waste lines within the building shall be glass or mechanical “end-filled” laboratory
line at the discretion of the University Project Manager.
Water Piping
Copper tubing shall be used for all water piping and shall be type L hard drawn. Joints
shall be made with no-lead solder.
Before being placed into service, all new water lines, except those used exclusively as fire
lines, shall be disinfected in accordance with American Water Works Association
(AWWA) standards. Final connections to existing water lines shall not be made until this
procedure is completed satisfactorily.
Water Hammer Arrestors
Water hammer arrestors shall be installed on cold water piping to toilet rooms where
flush valves are used. The arrestors shall be the hydropneumatic type and shall be sized
properly to control water hammer. These should be Absorbtion or equal.
Any quick-acting automatic valves supplying equipment shall also have water hammer
arrestors installed.
Cold Water Make-Up Piping
All cold water piping shall be type L hard drawn seamless copper tubing.
All cold water piping joints shall be soldered, using no lead.
Parallel filters shall be provided on all incoming make-up water lines.
15430 PLUMBING SPECIALTIES
Electric Drinking Water Cooling Systems
Electric water coolers shall be wall mounted, semi-recessed and shall be supported by
carriers similar to Josam No. C-352.
The coolers shall be equipped with a basin of 18-8 stainless steel, bubbler, water valve,
pressure regulator, and a sealed refrigeration system with air-cooled condenser.
P. 15-20
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
The front panel of a unit shall be removable and units shall be so constructed that the
refrigeration unit can be removed without moving the cooler from the wall.
No “hot water for coffee” type dispensers shall be permitted.
In public areas the water cooler shall be accessible to the handicapped.
Deionized Water
Current piping is stainless steel. Polypropylene is adequate for new extensions. If users
need higher quality water than what is available (1 meg-ohm/0.997 micro-moh at the
fixture), polishers shall be added in the laboratory.
Eyewash
An eyewash shall be installed in labs that have at least one fume hood.
Where corrosive materials are used in a laboratory, the eyewash shall be installed within
10 feet of the corrosive process.
The eyewash instrument shall be dual-port eyewash, which can be operated hands-free,
such as Kewaunee model No. W0934-00, or an approved equal.
The installation shall allow flow regulation on the eyewash and provide drainage for any
spillage. Tempered water at the eyewash is also recommended.
Safety Showers
Safety showers shall be installed within laboratories where space allows.
As a minimum, there should be a safety shower 10 feet from the laboratory (in the
hallway).
The shower shall be equipped with a continuous flow valve. Tempered water is
recommended. Drainage shall be provided for the safety shower.
15440 PLUMBING FIXTURES
Water Closets
Water closets shall be wall hung where walls are masonry backed up with adequate wall
hanger (a Zurn 300-lb support device has feet bolted to the floor and wall support). Floormounted water closets shall be used with non-masonry walls, or in replacement work.
Water closets shall be vitreous china with water-saver fixtures.
Wall-hung water closets shall be American Standard Afwall EL 1.6 #2257.103 with
Olsonite seat.
Floor-mounted water closets shall be American Standard Madera EL 1.6 10-in.
#2234.015 with Olsonite seat. Cadet #3043.1.2 shall be used at accessible locations.
December 1998
R
P. 15-21
DIVISION 15
DESIGN AND CONSTRUCTION STANDARDS
MECHANICAL SYSTEMS
FACILITIES MANAGEMENT SERVICES
Flush valves shall be Sloan Royal flushometer valves.
Urinals
Urinals shall be wall hung, vitreous china with Zurn 300 support device. Urinals shall be
similar to American Standard Washbrook 1.0 #6501.1.1 with stainless steel strainer.
Allbrook 1.0 #6541.132 shall be used at accessible locations.
Flush valves shall be Sloan Royal flushometer.
Lavatories
Lavatories shall be wall hung, vitreous china, American Standard Lucern #0355.012, or
drop-in china sink bowl (American Standard Aqualyn #0476.028) for use with corian
countertops. Mildew-resistant caulking shall be used around the bowl.
Lavatory carriers shall be of the institutional type with support plate, bearing plate steel
uprights, and block bases for supporting lavatory fixtures with concealed hangers.
Carriers shall be similar to Josam C-356.
Lavatory supply and waste lines shall enter the wall to allow for easier cleaning and better
sanitation.
At least one hose bib shall be provided on the hot and cold water supply under one
lavatory in each restroom.
Faucets shall be Chicago faucets: 4-in. center #802A faucet, #317 4-in. blade handles,
E12VP aerator, #245 Control-A-Flo cartridge, polished chrome plate finish (CP); #327A
non-removable grid drain or #337 offset at an accessible sink; #1005 or #1006 keyed
stop, chrome finish.
Single Showers
Shower heads shall be self-cleaning, water-saver, and vandal-proof type solidly attached
to the shower stall.
Shower controls shall be Powers Series 420, thermostatically controlled, with chromeplated metal levers.
Showers shall have Dole flow controls, limiting water flow to 2 gpm, installed between
the mixing valve and the showerhead.
Gang Showers
Showerheads and controls shall be the same as for single showers.
Piping supplies shall be from below the floor.
Units shall be manufactured by Bradley or equal.
P. 15-22
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
Antifreeze Hose Bibs
Antifreeze hose bibs are needed adjacent to all building entrances for the purpose of
washing down walks and entrances. Key type shall be used.
Service Sinks
Service sinks shall be similar to Stonite Precast Terrazzo Mop Service Basins as
manufactured by Stonite Products Company. Service basins shall be 24 in. square with 3in. wide and 12-in. high shoulders and shall be cast as a single unit of terrazzo. The sides
of the service basins installed against any wall shall be provided with stainless steel tiling
flanges cast integral with the basin and extending 2-in. above the shoulders. The exposed
side of the service basin shall be provided with integral cast stainless steel caps extending
over the top of the shoulder and extending at least 1.5 in. down the sides. A 3-in. drain
connection with stainless steel strainer plates and traps shall be provided. Counter
flashing shall be installed as required.
Service sink fittings shall be equal to Chicago faucet No. 897 with bucket hook, wall
brace, 0.75-in. threaded hose connection, vacuum breaker, and integral stops.
Roof Drains
Roof drains shall be Zurn or equal.
The drain body, horizontal rain leaders, and the first vertical 18 in. of roof penetrations
shall be insulated.
Laboratory Equipment
Where laboratory equipment is shown on the general construction drawings, this
equipment shall also be shown on the mechanical and electrical drawings. The equipment
shall bear the same identification numbers on all sets of drawings.
15453 PUMPS
General
Standby pumps shall be provided for all hot water heating and chilled water circulating
systems.
All pumps shall have bronze impellers.
Pump schedules shall indicate system served, operation (primary or backup), gpm, pump
head, rpm, motor horsepower, location, make and model number, and electrical
characteristics.
A single gage shall be connected to the discharge and suction side of each pump and
across the strainer so that the differential pressure can be observed. No trumpet valve is
allowed.
December 1998
P. 15-23
DIVISION 15
DESIGN AND CONSTRUCTION STANDARDS
MECHANICAL SYSTEMS
FACILITIES MANAGEMENT SERVICES
Section 15985 provides temperature control requirements.
Pumps – Closed Coupled
Closed-coupled pumps are not permitted over 0.5 hp.
Pumps – Base Mounted, End Suction
Pumps shall be electric-motor-driven, centrifugal, single-suction, single-stage pumps.
Pumps shall be bronze fitted, with bronze impeller, with close-grained semisteel
vertically split casing (125 psi), provided with mechanical seals designed for the
operating conditions shown on the plans. Pumps shall be provided with sleeve bearings
and an oil reservoir. A drop-out coupling shall be provided.
Pumps shall have a sleeve bearing, specially selected for quiet operation at 1750 rpm. The
motor size shown on the drawing shall be the minimum acceptable. A pump motor should
operate within the service factor of the motor, providing that the service factor is
acceptable to the pump manufacturer. The motor shall not exceed the nominal hp at the
specified delivery and head.
Discharge increasers shall be concentric and located at the pump discharge nozzle.
Suction pipe reducers shall be eccentric, located at the pump suction nozzle and at least
five diameters of straight pipe shall be installed before the inlet or along the sweep elbow.
(Suction diffusers in lieu of straight pipe section may be used.) A 0.75-in. drain shall be
provided from each base plate to the nearest floor drain.
Pumps shall be selected so that the ratio of impeller diameter to the maximum diameter
possible in the casing shall not exceed 0.85. A purge cock shall be provided in the casing
and gage tappings shall be provided in pump suction and discharge.
All piping connections to pumps shall be supported independently so that no strain is
imposed on the pump casing.
Pumps installed on “slab-on grade” shall be mounted on a 6-in. high concrete pad with
anchor bolts. The space between pad and base shall be grouted to eliminate all voids.
Pumps shall have rear pull-out design for removal of the impeller without disturbing the
motor alignment or piping.
Pumps installed on supported slabs shall be provided with concrete inertia subbases with
spring isolators.
Pumps shall be B&G, Taco, Armstrong, or equal, as approved by the Design Consultant.
In-Line Pumps
Pumps shall be centrifugal and single-stage, complete with motor, mechanical seals,
bronze fittings, bronze impellers, and a flexible coupler with safety guard. The pumps
shall also be dynamically and hydraulically balanced.
The pump motor shall be supported independently.
P. 15-24
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
Constant Pressure Pumps
Where constant pressure pumps are required on the potable water system, they shall be
installed in duplicate and be similar to Peerless Pumps’ Variable Frequency Drive
pumping system.
15460 WATER HEATERS
The design shall include steam-fed capability for winter use, and gas-fired capability for
summer use. Electric water heaters shall be storage type, to be used only in building
locations that are remote to steam/gas utilities.
Instantaneous hot water generators shall contain a cupronickel coil (10% nickel) and all
the auxiliaries required for the above type generator with the exception of the circulating
pump. The steam control valve on instantaneous hot water generators shall be air-loaded
(if air is available) or steam-actuated. Self-contained valves are not acceptable.
Instantaneous hot water generators shall be similar to those of Leslie, Constantemp,
Armstrong, or Graham companies.
15481 COMPRESSED AIR SYSTEMS
Air Compressors
Existing compressor capacity shall be verified before tying in new devices.
When after coolers are specified on air compressors, they shall be air-cooled or shall be
cooled with recirculating process water. Water cooling through equipment to a drain is
not permitted.
Compressed Air Piping
Compressed air piping above grade shall be Schedule 40, black steel conforming to
ASTM A 53. Fittings shall be malleable screwed end.
15488 NATURAL GAS SYSTEMS
Natural gas piping is available to some, but not all, campus buildings. The University
Project Manager shall review whether new service is required.
15510 HYDRONIC PIPING
Manual vents are standard but automatic vents can be considered in special situations.
Where vent location is high or otherwise inaccessible, the following procedure can be
followed: Install valve at vent chamber, then extend 0.375-in. tubing to the nearest janitor
sink or mechanical room floor drain and terminate with a ball valve. Use automatic water
December 1998
P. 15-25
DIVISION 15
MECHANICAL SYSTEMS
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
feed set to maintain proper system pressure. Add cold water makeup at the air vent line
above an air-eliminating device.
Glycol systems shall be equipped with a mix-and-fill tank with manual fill capabilities,
hose bib from domestic water for tank filling, and tank level alarm. Direct-connect city
makeup lines to glycol systems are NOT permitted.
Provisions shall be made for draining and air venting of all water coils.
All new hot water and chilled water systems that are independent of the central systems
shall be arranged for shot feed chemical treatment. In each such system, the equivalent of
one Calgon 100L Mircomet pot feeder shall be provided, including pressure gage and
flow indicator. The pot feeder to the system shall be hard-piped; using a hose is NOT
acceptable.
The University will provide all treatment chemicals except for chemicals for the flushing
system. A University representative will supervise chemical treatment.
After all items of equipment have been connected to the system (but prior to connecting
to existing systems and prior to acceptance by the University), the hot and chilled water
system shall be chemically cleaned as follows:
1. Drain and refill the system using trisodium phosphate, 1 lb for every 50 gal in the
system.
2. Fill, vent, and circulate the system with this solution, allowing it to reach design or
operating temperatures.
3. After circulating a few hours, the system should be drained completely, strainers
removed and cleaned, dirt legs and pockets opened and cleaned, and then refilled with
fresh water. Immediately notify the University Project Manager.
Reduced pressure principal backflow preventers shall be installed on all make-up water
lines. Drains shall be piped to the nearest floor drain.
Hot Water, Chilled Water, Vent Piping
All supply water piping shall be graded up and return graded down in the direction of the
flow. At all high points in the piping system, manual air vents shall be installed to
eliminate air pockets at initial fill.
All water piping 2.5 in. and larger shall be black steel pipe, ASTM A 53, Grade B.
Pressure requirements shall be met. Piping 2 in. and smaller shall be copper, type L, hard
drawn.
All water piping that is 2 in. and smaller shall be screwed or soldered as applicable; water
piping that is 2.5 in. and larger shall be welded, flanged, or Victaulic (with rolled, not
grooved, fittings).
P. 15-26
December 1998
DESIGN AND CONSTRUCTION STANDARDS
DIVISION 15
FACILITIES MANAGEMENT SERVICES
MECHANICAL SYSTEMS
Identification Symbols and Colors for Water Piping
Service
Symbol
Field Color
Hot water heating supply
HWS (Zone No.)
Burnt orange
Hot water heating return
HWR (Zone No.)
Burnt orange
Hot water heating expansion line
HW Exp.
Burnt orange
Hot water heating drain
HW Drain
Burnt orange
Chilled water supply
CHWS (System No.)
Dark green
Chilled water return
CHWR (System No.)
Dark green
Condenser water supply
Cond. Sup.
Light green
Condenser water return
Cond. Ret.
Light green
Flow arrows shall be provided every 10 feet and at each change in the direction of the
pipe and at take-offs.
Refer to ANSI A13-1, latest version, for size of lettering.
Hydronic Specialties
Strainers
Construction startup strainers shall be fine mesh. After one month of operation, the
strainer shall be changed to a larger mesh specified for normal use.
Strainers ahead of circulating pumps shall be large mesh (at least 0.1875 in.) and stainless
steel construction. All strainers shall be valved and capped for blowdown.
Air Separators
Air separators shall be installed in each hydronic system. They shall be full line size.
Air separators 2 in. and larger shall have tangential inlets and outlets and be ASME rated.
These separators shall be similar to those of Bell & Gossett Rolairtrol.
Expansion Tanks
Tanks shall be steel, ASME constructed, complete with inlet, drain, overflow, aircharging valve, airtrol fitting, and make-up connections. Expansion tanks shall be
diaphragm type.
Expansion tanks shall have no direct connection to the air system.
A Chicago quick-disconnect fitting shall be provided. It should have a shut-off valve for
compressed air, which is necessary for manual charging of the system.
December 1998
P. 15-27
DIVISION 15
DESIGN AND CONSTRUCTION STANDARDS
MECHANICAL SYSTEMS
FACILITIES MANAGEMENT SERVICES
Flow Meters
Flow meters shall be installed at all terminal equipment and air handling units, as well as
any horizontal branches from the building risers (to balance at each floor level).
For lines 2 in. and under, meters shall be similar to Armstrong circuit balancing valve
with vernier controls.
For lines 2.5 in. and larger, a venturi-type measuring device shall be used.
Gage Piping
All gage piping on steam systems shall be steel (Schedule 40 on low pressure and
Schedule 80 on high pressure).
Gage cocks (low pressure) or ball valves (high pressure) shall be provided for isolation.
Cooling Coil Condensate Drain Piping
All cooling coil condensate drain piping shall be Schedule 40 PVC with solvent weld
joints.
Section 15790 describes appropriate trap sizing.
No piping shall be less than 1-in. in diameter.
Cleanouts shall be provided as required.
15520 STEAM AND STEAM CONDENSATE PIPING
Steam Piping
All steam piping shall be graded down in the direction of flow 1 in. in 40 ft. At all low
points in the steam piping system, a drip station shall be installed. Offsets and bends shall
be provided wherever possible to allow for expansion and to control pipe movement.
Anchors and expansion joints shall be provided as required and detailed on the drawings.
Steam piping shall be Schedule 40 black steel, ASTM A 53, Grade B.
Joints 2 in. and smaller shall be screwed; joints 2.5 in. and larger shall be welded or
flanged. All high-pressure piping shall be welded.
All steam pipe strainers and traps shall be removed and cleaned prior to acceptance by the
University.
TO BE ACCEPTABLE, ALL CLEANING WORK IN THIS SECTION MUST BE
WITNESSED BY THE UNIVERSITY PROJECT MANAGER.
Drip legs shall be, at a minimum, half the size of the steam main, 18 in. in length with a
blowdown valve at the bottom. The trap line connection shall be located in the center of
the drip leg.
Calculations for expansion joints shall be documented, as described in Section 15010.
P. 15-28
December 1998
DESIGN AND CONSTRUCTION STANDARDS
DIVISION 15
FACILITIES MANAGEMENT SERVICES
MECHANICAL SYSTEMS
Gasket material shall be included in the specifications for each class of pipe. Submittals
are required for high-pressure steam applications.
Section 15250 of this document provides the requirements for insulation.
Identification Symbols and Colors for Steam Piping
Service
Symbol
Field Color
Service
Symbol
Field Color
Steam, high pressure
Steam – 175
Green
Condensate return
from:
Steam, high pressure
Steam – 125
Yellow
High pressure steam
Cond. – 175
Yellow
Steam, high pressure
Steam – 100
Yellow
High pressure steam
Cond. – 125
Yellow
Steam, intermediate
pressure
Steam – 65
Yellow
High pressure steam
Cond. – 100
Yellow
Steam, intermediate
pressure
Steam – 25
Yellow
Intermediate steam
pressure
Cond. – 65
Yellow
Steam, intermediate
pressure
Steam – 15
Yellow
Intermediate steam
pressure
Cond. – 25
Yellow
Steam, low pressure
Steam – 5
Yellow
Intermediate steam
pressure
Cond. – 15
Yellow
Condensation Pump
Discharge
Cond. – PD
Yellow
Low steam pressure
Cond. – 5
Yellow
Steam Condensate Return Piping
All gravity return condensate lines shall be pitched down toward the direction of flow,
in. in 30 ft.
1
All condensate return lines in buildings shall be Schedule 80 black steel, ASTM A 53,
Grade B.
Joints 2 in. and smaller shall be screwed; joints 2.5 in. and larger shall be welded or
flanged.
Steam and Condensate Specialties
Traps and strainers shall be installed with isolation valves and telltale drains to facilitate
cleaning and maintenance and to check proper operation of the trap.
For low-pressure drips, float and thermostatic traps shall be used.
For high-pressure drips, thermodynamic, or float and thermostatic traps shall be used.
For modulating service, float and thermostatic traps with vacuum breakers shall be used.
Pressure-Reducing Valves
The Main Steam Pressure Control Stations shall consist of an air-operated diaphragm
control valve and a remotely-adjustable external air-operated pressure control pilot. Air
lines shall be provided under ATC.
December 1998
P. 15-29
DIVISION 15
DESIGN AND CONSTRUCTION STANDARDS
MECHANICAL SYSTEMS
FACILITIES MANAGEMENT SERVICES
The diaphragm control valve shall have a flanged cast bronze body with a 250 psi
pressure rating. It shall have hardened stainless steel trim with a stellited seat ring. The
valve shall be single seated and suitable for dead-end service with a 250 psi pressure drip.
It shall operate on a 0 to 22 psi air signal from the control pilot and be normally closed
(air to open).
The air-operated pressure control pilot shall be of the differential type suitable for
readjustment from a remotely-located air loading panel.
The pressure controller shall be capable of maintaining an outlet pressure within plus or
minus 0.5 psi when passing flow from zero to the maximum specified, regardless of
gradual inlet pressure variations.
The Steam Pressure Controller shall consist of a diaphragm control valve, type DDL or
GPK, and a control pilot, type UDDV, and a remote panel loader, type PPF, all as
manufactured by the Leslie Company. The remote panel loader shall have integral filters
or be preceded by strainers.
Valves shall be as manufactured by the Leslie Company, or an approved equal.
Consideration shall be given to two-stage reduction when required by pressure and twostage parallel reduction when required by varying load conditions.
15530 REFRIGERANT PIPING
Refrigerant liquid and suction piping shall be type L, hard drawn ACRS tubing.
A nitrogen purge shall be maintained when soldering all joints. Copper-to-copper joints
shall be made with a brazing alloy similar to Sil-Fos. Copper-to-brass joints shall be
made with silver solder.
Main piping fittings for dryers, sight glasses, expansion valves, and controls shall be flare
or compression-type fittings.
Prior to being charged with refrigerant, the system shall be evacuated to 500 microns and
held for at least 24 hours under this vacuum.
Double-suction risers shall be employed on systems with capacity reduction and where
required by lift.
Precharged lines are not acceptable.
Identification Symbols and Colors
for Refrigerants
P. 15-30
Service
Symbol
Field Color
Freon 11
Freon 11
Purple
Freon 12
Freon 12
Purple
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
Refrigerant Specialties
Isolation valves shall be provided at all specialties.
Refrigeration
Installations shall be complete with dryers, sight glass, and thermostatically-controlled
solenoid valves for pump down operations.
Where defrost units are required, they shall be operated electrically with adequate space
provided to replace defrost elements. Defrost shall not be limited to electrical units. In
larger installations, hot gas defrost is preferred.
Installations shall be provided with necessary protective devices including, but not
limited to, electric overload devices, low-suction pressure cutouts (manual reset), high
head pressure cutouts (manual reset), low-lube oil pressure cutouts (manual reset), oil
traps, crankcase heaters, and antirecycling.
Condensing systems shall be designed for 0 °F ambient conditions, using variablefrequency fans.
15540 HVAC PUMPS
Chiller run-around pumps shall be constant-volume. They shall be decoupled from the
distribution loop, and as load is added to the system, decoupled from the distribution loop
via a primary/secondary piping bridge. The distribution loop shall be sized for a 15 °F
water temperature drop and served by variable-speed pumps. Load-side pumps shall be
typically constant-volume, but variable-speed pumps may be warranted in some cases.
15545 CHEMICAL WATER TREATMENT
The Design Consultant shall contact the University HVAC foreman for current
requirements.
15582 STEAM CONDENSATE RETURN UNITS
Steam condensate pumps shall be duplex type with cast iron receivers (not steel).
Steam-powered pumps can be considered, and shall be reviewed with the University
Project Manager on a project basis.
15680 WATER CHILLERS
When tie-in to existing central chilled water has been determined to be not feasible (by
consensus between the Design Consultant and the University), selection of a new chiller
shall be reviewed with the University Project Manager at the conceptual design stage.
December 1998
P. 15-31
DIVISION 15
DESIGN AND CONSTRUCTION STANDARDS
MECHANICAL SYSTEMS
FACILITIES MANAGEMENT SERVICES
The Life Cycle Cost Analysis model provided by the University shall be used as the basis
of the selection.
Sufficient clear space shall be allowed, equal to the length and width of the machine for
tube pull clearance.
Refrigerant selection shall be discussed with the University Project Manager prior to
equipment selection.
A beam with a minimum 4-ft clearance shall be provided above the chiller or sufficient
clear space shall be allowed above and around the machine for using a gantry for
compressor replacement.
Section 15170 describes motor inrush current and voltage drop requirements for starting.
The acceptability of across-the-line starters shall be reviewed case by case.
The chiller control package shall control run-around and injection pumps, and shall be
interfaced with the University DDC system for remote start/stop and chilled water
setpoints.
15711 FACTORY-FABRICATED COOLING TOWERS
An induced-draft cooling tower is preferred; a forced-draft cooling tower can be
considered where space is an issue.
Forced-draft units shall be similar and equal to Baltimore Air Coil “V” line with PVC fill.
The units shall have complete winterization capability, including heat tracing of piping.
Cooling tower location must be approved by the University.
Indoor sumps are required where year-round cooling is necessary.
Water conditioning equipment for the cooling tower shall be compatible with the
University’s current water treatment program (molybdate-based). The University
Operations Department will provide specifications.
Chemicals shall be provided by the University.
Cooling towers shall be selected at 95 °F DB, 78 °F WB
Lakos-type particulate separators shall be provided on condenser water systems.
15755 HEAT EXCHANGERS
Steam-to-water converters shall have steam in the shell and water in the tubes. ASME
rating is required. Tubes shall be 90-10 cupronickel, ASTM B 111, and velocity shall be
less than 5 ft/sec.
Sufficient clear space (no less than the entire length of the converter) shall be provided to
allow for tube bundle removal. Tube bundles shall be straight or “U” tube design.
P. 15-32
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
Vacuum breakers shall be installed in the piping for modulating steam supply. There shall
be a minimum 12-in. drip leg to trap inlet. Vacuum breakers shall be provided on the
shell.
Converters shall be selected at 2 psig steam supply and 0.0005 fouling factor.
Using a simple check valve for a vacuum breaker is not acceptable. Hoffman Model No.
69 shall be used.
“Once-through” air systems shall be considered for heat recovery applications.
15781 PACKAGED HEATING AND COOLING AIR HANDLING UNITS
Fans and motors of 5 ton and larger shall be on a common spring isolation base or rail.
All fans 0.75 hp and above shall be Class II fans.
Casing shall be double-walled, with hinged access doors.
Mixed air chambers shall have motor-operated dampers.
A full access section width casing with access door shall be used to separate the chilled
and preheat coils.
Compressor staging shall be a function of unit size, with off-loading capability
considered.
Dampers shall have edge seals and be low-leakage (2%) type.
There shall be access doors to all components.
There shall be interface with the University DDC system for remote start/stop and an
alarm for compressor failure.
All units shall have a dedicated set of minimum outside air dampers for ventilation
requirements. The dampers shall be two-position, and a second set of modulating outside
air dampers shall be provided, as required, for economizer operation or tracking with
exhaust air.
Use of “air blenders,” which provide good outside return air mixing, should be
considered.
15782 ROOFTOP HEATING AND COOLING UNITS
The Design Consultant shall obtain permission from the University Project Manager
before designing packaged rooftop units for University projects.
Air-cooled packaged air conditioning equipment shall be equipped with low ambient
cooling to permit operation to 0 °F ambient temperature.
All units shall have a dedicated set of minimum outside air dampers for ventilation
requirements. The dampers shall be two-position, and a second set of modulating outside
December 1998
P. 15-33
DIVISION 15
DESIGN AND CONSTRUCTION STANDARDS
MECHANICAL SYSTEMS
FACILITIES MANAGEMENT SERVICES
air dampers shall be provided, as required, for economizer operation or tracking with
exhaust air.
Rooftop package air conditioners 5 ton and larger shall be mounted on structural steel
channel curbs with curb vibration isolation rails. Smaller units may be mounted on the
manufacturer’s prefabricated curbs.
Details and catalog cuts of the unit shall be submitted prior to design. Units must be
manufactured for that application.
Where steam or hot water is not available, a gas-fired heat exchanger shall be used. (An
electric heating coil is NOT acceptable.)
A full access section width casing with door shall be used to separate the chilled and
preheat coils.
Casings shall be double-walled, with hinged access doors where available as an option.
15790 AIR COILS
Separate drain pans for each stacked cooling coil shall be provided.
A schedule shall be shown on the construction documents with the trap detail, indicating
the trap depth dimensions for each coil location (this shall not be left for the Contractor to
calculate). The formula used as the basis for these dimensions shall be shown on the
schedule as well.
Access doors shall be provided on the upstream side of all coils.
Clearance shall be provided for the full-finned width of the coil for removal.
Cooling coil face velocities shall be designed for 425 fpm and shall not exceed 500 fpm.
Water coils shall be fully drainable.
Air vents shall be provided at the highest point.
Hose and drain valves shall be provided with isolation valves.
Steam coils shall be piped to prevent freeze-ups. This shall include vacuum breakers and
adequate drip leg-to-trap inlet, which may dictate that units be mounted on an angle iron
frame above the housekeeping pad.
100% outdoor air preheat coils shall be of the steam distributing type with external face
and bypass control, as manufactured by Wing Coils, or an approved equal. Coils shall be
double trapped. Control valves shall not be the modulating type for preheat application.
If reheat is required for dehumidification, a dual hot water coil arrangement can be used,
splitting the temperature rise between the two coils.
Hot water shall be used for all reheat coils and all preheat coils with less than 75%
outside air requirement.
Water coils shall be piped in counterflow configuration.
P. 15-34
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
On runaround loop applications, appropriate corrosion-resistant coating shall be provided
for any corrosive atmosphere.
Chilled water coils shall be designed for a 15 °F water temperature drop.
Tube-wall thickness, fin material, fin spacing (with a maximum of 10 fpi), shall be
reviewed based on application with the University.
All cooling coil casings and condensate drain pans shall be stainless steel.
15831 FAN COIL UNITS
Ceiling-hung fan coil units shall be avoided wherever possible. However, if the use of
ceiling-hung units is deemed necessary, then such units shall be made as accessible as
possible, preferably installed in corridor ceilings and ducted to the rooms they serve.
Vertical floor-mounted units are acceptable alternatives where necessary because of
ceiling height limitations for concealing ductwork, and so forth.
Specified control valves may be sent to the fan coil manufacturer to be factory-mounted.
Fan coils shall be sized so that the NC level does not exceed the recommended levels
given in Table 2, Chapter 43 of the ASHRAE Systems and Applications Handbook, latest
edition.
When fan speed control is not specified, fan speed switches (low-medium-high) are
required.
Four-pipe fan coil systems are preferred to two-pipe.
Finish shall be submitted to the University representative with a color chip for approval.
15832 FINNED-TUBE RADIATION
A commercial-grade 16-gage face enclosure shall be used. A residential-grade enclosure
is not permitted. The finish shall be submitted to the University Project Manager with a
color chip for approval.
Finned-tube radiation shall be designed for an average hot water temperature of 180 °F or
1 psig steam supply, to be reset with the outside air temperature.
Finned-tube radiation shall be selected to be consistent with the existing perimeter
radiation type.
December 1998
P. 15-35
DIVISION 15
DESIGN AND CONSTRUCTION STANDARDS
MECHANICAL SYSTEMS
FACILITIES MANAGEMENT SERVICES
15835 UNIT HEATERS
Isolation valves shall be provided on each item.
Unit heaters shall be designed for an average hot water temperature of 180 °F or 1 psig
steam supply, to be reset with the outside air temperature.
Design drawings shall indicate all selection criteria.
The heater finish, with a color chip, shall be submitted to the University Project Manager
for approval.
Inverted flow units shall be used for all floor-mounted units.
15840 UNIT VENTILATORS
Unit ventilators shall not be used.
15850 FANS AND EXHAUST SYSTEMS
When return air fans are required in variable-volume systems, flow measuring stations
shall be provided in the supply and return ducts to ensure proper tracking of the supply
and return fans.
All fans, including power ventilators over 20 in. in diameter, shall be belt-driven with
solid sheaves, as described in Section 15170.
When available, permanently-lubricated bearings shall be used, with a minimum 200,000hr life. On others, extended lube shafts, 0.126-in. steel tubing and flush plugs with relief
set at 5 psig shall be specified.
The fan schedule on the drawing shall be complete, giving area served, fan location,
method of control, and performance characteristics. Controls must not be placed in public
areas. If fans are interlocked, the schedule shall indicate the unit with which the fan is
interlocked.
Fans shall be AMCA rated for sound and air performance.
All fans shall be statically and dynamically balanced and test run at the factory.
The motor horsepower shall not be less than 120% of fan bhp, non-overloading.
Fume Hood Exhaust Systems
Specific requirements for laboratory and industrial exhaust systems shall be reviewed
with the University Project Manager and the University EH&S Office.
Fume hood exhaust systems shall be designed in accordance with the American
Conference of Governmental Industrial Hygienists (ACGIH) and ANSI Laboratory
Exhaust Standards Z 9.5, latest edition.
P. 15-36
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
All systems shall have an adequate supply of make-up air tempered to room temperature.
Total make-up air quantity shall not exceed that required to maintain the specified
pressure relationship for the space (0.05 in. wc, negative static pressure relative to the
corridor or adjacent non-laboratory spaces). Temperature control of the space shall not
depend on exhaust air bypass through the hood.
A specialized hood/exhaust washdown and duct system shall be provided where
perchloric acid is used.
Fume hood exhaust fans shall have acid-resistant coating, two coats air-dried “Heresite”
or equal. Design static shall not be less than 1-in. static pressure. Spark resistance is
required for explosive atmospheres. Where design conditions do not permit the use of
coatings, requirements shall be discussed with the University Project Manager.
Exhaust fans serving fume hoods shall be located at the discharge end of the system to
minimize the amount of positively-pressurized ductwork
Exhaust fans shall discharge at a sufficient height above the roof level to provide safe
discharge and dilution of hazardous chemicals, as outlined in Chapter 15, “Airflow
Around Buildings,” in the latest edition of the ASHRAE Fundamentals Handbook. Exit
velocity shall be 3,000 fpm (minimum).
Duct systems and fans serving hoods used with combustible materials shall be of sparkproof construction and shall not be PVC coated.
Type 316 stainless steel ducts using mechanical joints with silicone seal or galvanized
ductwork coated with PVC shall be used depending on the chemicals being conveyed in
the system.
Hoods, fans, and discharges shall be tagged for type of service and fume hoods shall be
tagged with a fan service tag.
Exhaust fans and ductwork handling toxic fumes and/or radioisotopes shall have a selfadhering CAUTION sticker attached.
Existing terra cotta tile exhaust risers at Mellon Institute are of questionable condition
with regard to how tightly they may be sealed. Some have been noted to have low leakage
rates and others have higher leakage rates. The Design Consultant shall provide flexibility
in the sizing of new exhaust fans by oversizing the motors by 25%, but should pick a fan
that can operate at either the design cfm or a higher cfm (in case leakage is encountered).
An extra sheave shall be specified so that the fan can be properly balanced at no
additional cost to the University.
The preferred system design for multiple hoods is to manifold them with variable-volume
control. Where there is a central manifold exhaust system, as a minimum, one fan shall
provide stand-by with the capacity to match one of the remaining fans.
The OSHA requirement for a face velocity monitor on all fume hoods shall be adhered to.
All laboratory hoods and safety cabinets shall be equipped with visual and audible alarms
to warn laboratory workers of unsafe air flows.
December 1998
P. 15-37
DIVISION 15
DESIGN AND CONSTRUCTION STANDARDS
MECHANICAL SYSTEMS
FACILITIES MANAGEMENT SERVICES
Controls and dampers shall be of a type that, in the event of failure, will fall open to
assure continuous draft.
In accordance with NFPA Standard 45, automatic fire dampers shall not be used in
laboratory hood exhaust systems. Fire detection and alarm systems shall not be
interlocked to automatically shut down laboratory hood exhaust fans.
Auxiliary air supply hoods shall not be used.
15854 CENTRAL STATION AIR HANDLING UNITS
All air handling units shall have, at minimum, a dedicated set of two-position outside air
dampers for ventilation requirements plus a second set of modulating outside air dampers,
as required, for economizer operation or tracking with exhaust air.
A full coil section width casing with access door shall be used to separate the chilled and
preheat coils.
Schedules shall include area served, location, total and sensible cooling capacities,
entering and leaving temperatures (air and water) for all coils, motor horsepower, voltage,
heating capacities, steam pressure, team coil condensation rate, fan rpm, total air quantity,
outside air, and external and internal static pressures.
Insulated casings and plenums shall be specified for all units, including those serving heat
and vent applications. Casings for heat and vent applications shall have space for
installation of future cooling coil.
Units shall be installed to allow removal of all coils and filters. Clearance equal to fullfinned width of coil shall be provided to facilitate removal.
Units shall be mounted on internal vibration isolators and concrete housekeeping pads.
Units shall have a mixing box and filter box or a combination filter/mixing box properly
sized so as not to exceed the filter manufacturer’s recommended face velocities. Low
leakage dampers (2%) shall be provided for mixing box dampers.
Air blending-devices shall be installed on all central station air-handling units where air
stratification is a potential problem.
All cooling coil drain pans shall be stainless steel.
15860 CENTRIFUGAL FANS
Fan wheels shall be of backward inclined or airfoil design and shall be non-overloading.
Precision-ground shafts shall be sized so that the first critical speed is at least 25% over
the maximum operating speed.
Bearings shall be heavy duty self-aligning or roller pillow block type and selected for a
basic rating fatigue life (L-10) of 80,000-hour minimum, at maximum speed.
P. 15-38
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
The assembled fan shall be factory-tested and fan vibration shall not exceed 0.15 in./sec
peak velocity.
15865 TUBULAR CENTRIFUGALS
Wheels shall be non-overloading air foil centrifugal type.
Static and dynamic balance shall match the wheel cone and fan inlet cone.
Welded steel vanes for air straightening shall be provided for the fan discharge.
Bearings shall have a minimum 200,000-hour life at maximum operating speed.
15870 POWER VENTILATORS
Power ventilators shall have non-overloading, backward inclined centrifugal wheels.
Direct-drive motors may be used for wheels of diameter smaller than 20 in. and shall be
matched to fan load. For wheels 20 in. and greater in diameter, a belt drive shall be used.
Drives shall be sized for a minimum of 150% of driven horsepower.
Birdscreen of 0.5-in. galvanized wire mesh shall be installed.
A NEMA 1 disconnect switch shall be factory-wired to the motor.
15886 AIR FILTERS
Filters for comfort systems serving offices, classrooms, and other noncritical areas shall
be 50% efficiency cartridge filters, where space allows.
Filters for systems serving critical laboratory areas, animal rooms, and special areas will
be dictated by project requirements. The Design Consultant shall review specific
requirements with the University Project Manager.
Filters shall have separate holding frames with side access and slide-out frames properly
sized in accordance with the filter manufacturer’s guidelines. Frames shall be located to
permit removal of the entire frame for filter replacement.
Filter sections shall be provided with a filter differential pressure gage.
15891 METAL DUCTWORK
General
Duct sizes shown shall be the inside clear dimension.
ASHRAE and/or SMACNA shall be used as a guide.
Pressure classification shall be specified on the drawings.
All metal ductwork shall be crossbroke to ensure rigidity.
December 1998
P. 15-39
DIVISION 15
DESIGN AND CONSTRUCTION STANDARDS
MECHANICAL SYSTEMS
FACILITIES MANAGEMENT SERVICES
All rectangular elbows with a depth greater than 18 in. shall have double thickness
turning vanes.
Every branch duct shall include a 45° transition (no splitter dampers required).
Inlet and discharge ductwork configuration shall conform to the SMACNA HVAC Duct
Design Manual.
Two-in. wide, adhesive-backed vinyl cloth labels shall be used on all ductwork. Label
lettering shall identify both the medium being conveyed and the direction of flow.
Dampers
Dampers shall be installed in all branch ducts for balancing and shall be indicated on the
drawings. All balancing shall be done with branch duct dampers and NOT with diffuser
dampers.
Ducts whose smallest dimension is 8 in. or greater shall have multi-leaf opposed blade
volume dampers with manual quadrants calibrated to show the position of the damper.
Damper blade widths shall not exceed 6 in. Quadrants shall be oriented so that the handle
is parallel to the direction of air flow, when the damper is wide open.
Access Doors
Hinged access doors shall be installed at all automatic dampers, fire dampers, reheat
coils, and other apparatus requiring inspection and servicing.
Doors shall be suitable for the pressure classification and shall open against static
pressure in a duct.
Doors shall be fully gasketed and insulated when installed in insulated ductwork.
Door sizes shall be specified to be adequate for the intended purpose.
Flexible Connections
Flexible connections shall be provided at connections to ALL moving equipment.
Flexible Ductwork
Flexible ductwork shall not exceed 6 ft in length.
Fire Dampers
Fire dampers shall be installed where required by BOCA and NFPA.
Temperature rating of fusible links shall be 160 °F.
Frames shall be large enough so that there will be no obstruction to airflow when the
dampers are open. Construction and arrangement of fire dampers shall be as approved in
each case prior to installation. Access shall be provided for replacement of links and so
labeled.
P. 15-40
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
Fire dampers shall be UL approved and so labeled and installed, and shall comply with
the requirements of BOCA and NFPA 90A.
15920 SOUND ATTENUATORS
Section 15010 discusses sound pressure level requirements. Analysis shall be required for
both supply and return systems. Self-generated noise shall be taken into account in the
designer’s calculations.
Drawings shall indicate velocity, static pressure loss, and decibel attenuation through
octave bands.
Laboratory testing shall be performed by an independent laboratory.
15930 AIR TERMINALS
Variable Air Volume Boxes
Variable air volume (VAV) systems shall typically be zoned so that three to five offices
are ganged on a thermostat/box. Offices grouped together shall be ganged in a logical
manner, such as having the same floor area, building face exposure, and similar internal
loads.
VAV boxes shall have a minimum position setting for ventilation air requirements. Use
of reheat coils on the boxes for temperature control shall be minimized to special
circumstances, such as interior spaces with the potential for no internal load.
VAV boxes with perimeter radiation shall be sequenced from the same room thermostat
to ensure that the systems do not “fight” each other.
VAV boxes that are DDC type shall have factory-installed controls.
The schedule shall include minimum and maximum cfms, noise criteria (NC) levels, and
coil ratings.
When multiple boxes are used to serve a single zone, all shall be controlled from a single
thermostat.
Location of all boxes shall be accessible for maintenance.
Box controls shall be pressure independent. No system-powered boxes shall be used.
15932 AIR OUTLETS AND INLETS
As part of the design and shop drawings, the submittal shall include a complete tabulation
of these devices identified by room number and model, velocity, cfm, throw, pressure
drop, sound level and flow factor, and/or core area in square feet. The submittal shall also
include the manufacturer’s recommendations for air balancing procedures for the devices
submitted.
December 1998
P. 15-41
DIVISION 15
MECHANICAL SYSTEMS
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
Aluminum shall be specified for damp or wet atmospheres.
Use of self-controlled diffusers is not permitted without University approval.
Where possible, balancing dampers shall be located at the branch take-off instead of at
the diffuser to reduce air noise. Where this is not possible, the damper at the diffuser shall
be screwdriver operated.
Air supply to laboratories must keep temperature gradients and air turbulence to a
minimum, especially near laboratory fume hood faces and biological safety cabinets.
Diffusers shall be located so that they do not affect air flow patterns at the fume hood
face.
Outside air intakes shall be located to prevent entrainment of relief air, exhaust air, or
fume hood effluent. Wind tunnel tests shall be performed to assure the adequacy of the
design configuration where multiple buildings are located on the same site.
15970 HVAC CONTROLS
Static pressure control for variable-volume systems shall consist of a high quality sensor,
located by the Design Consultant on the drawings. If the system is DDC- controlled, the
transmitter shall be capable of controlling as low as 0-0.1 in. wc if necessary, at  0.5%
accuracy, comparable to the Dwyer series 607, or an approved equal.
With a DDC system, the freezestat and smoke detectors shall be hardwired to alarms, in
case of failure or malfunction of the DDC system. These sensors shall work
independently of the DDC system, but alarm the DDC system as long as the DDC system
is on line.
All pneumatic air shall be in copper tubing. Polyethylene tubing is allowed only for the
final 12 in. for connections to devices. Polyethhylene tubing is allowed in raceways or
conduit, in exposed mechanical spaces. Tubes shall be labeled at both ends.
15975 CONTROL SYSTEM EQUIPMENT
DDC controls are justified where more than two controllers are required. Otherwise, the
ATC system shall be pneumatic, with the exception that an extra set of contacts shall be
provided on the equipment motor starter (and a current switch for proofing), so that it can
be interfaced with the campus DDC system (by the University), for on/off control.
The DDC system shall be as manufactured by Johnson Control (Metasys), or American
Auto Matrix (AAM), unless otherwise notified. This applies to all major construction
projects, however the DDC controls typically are limited to central equipment, with all
terminal equipment controlled pneumatically. Other projects may require compatibility
with the existing ATC system.
All materials and equipment used shall be standard components regularly manufactured
for automatic temperature control purposes.
P. 15-42
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
All product and types shall have been thoroughly factory-tested and field-tested for
reliability and accuracy.
DDC work shall be bid separately under Division 18 (to be provided later), and the scope
limited to setting the panel, programming, and making final connections. All else shall be
accomplished by the Controls Contractor, which is bid under Division 15.
Supervision and checkout of the ATC system shall be by engineers/technicians employed
by the respective DDC or Controls Contractor. Checkout must be witnessed by the
University Project Manager or a designee.
Work Included
The Contractor shall furnish and install all material required for a complete and useable
automatic temperature control system.
The ATC system shall include: all control wiring, power wiring between the sensors,
actuators, valves, control panels, and other miscellaneous devices directly associated with
the ATC system.
Control dampers shall be furnished by the Controls Contractor and installed by the
Mechanical Contractor.
Control valves and wells for immersion elements shall be furnished by the Controls
Contractor and installed by the Mechanical Contractor.
Power wiring to the local ATC panel and wiring between fan motor holding coils and the
local ATC panel shall be the responsibility of the Electrical Contractor and coordinated
with Division 16. Control wiring shall be the Controls Contractor’s responsibility; the
DDC Contractor shall be responsible for power wiring any panels that are not shown on
bid documents at no cost to the University.
Submittals
The Design Consultant and the University shall review shop drawings concurrently. Two
complete sets will be required by the University for review.
The Design Consultant shall obtain the University’s review comments prior to forwarding
comments to the Contractor.
Submittals shall include the following:
• Written sequence of operation, which shall conform with the intent of the Specified
Sequence of Controls in the bid documents
• System schematic diagrams, including flow diagrams (DDC systems) and control
diagrams (pneumatic systems)
• Component list, including the manufacturer’s model numbers
• Wiring diagrams, including interlock wiring details
• Panel layoutinterior wiring interconnections and exterior panel face layout
December 1998
P. 15-43
DIVISION 15
MECHANICAL SYSTEMS
•
•
•
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
A separate control valve submittal that includes valve location, model number, design
flow, capacity factor (CV), and corresponding pressure drop at the design flow
A separate control damper submittal
A factory-printed specification sheet for review (for each device proposed)
Approval of submittal is required prior to installation of any equipment or part of a
system.
Equipment
The University has standardized on two DDC systems to be used on campus: AAM and
Metasys. If the renovation is within a building where one of these systems is well
established, the established system shall be specified as a proprietary system for the
renovation. If no system is established, both systems shall be specified competitively.
The architecture of the DDC system shall include distributed (standalone) controllers
compatible with the Metasys or AAM system, wired back to the central system.
A reduced copy of the schematic of the system served shall be installed on the face of the
control panel under an 11-in. x 17-in. plastic sheet.
15985 SEQUENCE OF OPERATION
Typical Control Sequences
The bridge control valve shall close when the “load side” circulating pump is off. The
conditions for the pump shutting off may vary, but normally when airside economizers
are available for off-season cooling, these pumps can shut off below 50 °F ambient
temperature.
Airside economizers shall be provided on all air handling units over 2000 cfm for free
cooling capabilities when outside air conditions warrant. Controls for economizer cycle
shall be based on dry bulb comparison of return air to outside air. Enthalpy control is not
required.
For VAV applications, the discharge air temperature shall automatically reset upwards
(based on a schedule from 55 °F to 65 °F) during colder outside air temperatures (say
75 °F to 30 °F).
Laboratory Fume Hood Controls
Laboratory exhaust control shall be based on room pressurization control (by TSI) for
new buildings (where air leakage from the room can be minimized), and fan tracking for
existing structures.
Fume hood face velocity control shall be based on closed-loop design, as manufactured
by Tech Air or Autoflow, Inc. (with parallel tube pitot-type sensor).
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DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
The fume hood control system manufacturer shall provide all the laboratory controls
including the air handling control, radiation controls, and room temperature controls as
well as the fume hood face velocity control and laboratory air flow tracking/room
pressure control system.
Each laboratory shall have individual room control.
Humidification Control
Humidification is not required unless needed to protect sensitive equipment or animals. In
laboratories where equipment may be operating below the dewpoint of the air supply, the
make-up air system shall be equipped with a reheat coil and controls to provide dehumidification capabilities year round. This is the case in biology laboratories that have
freezers and water-cooled equipment that may sweat on days when the outside
temperature is cool, but the air is 100% saturated with moisture.
15990 TESTING, ADJUSTING, AND BALANCING
Maintenance Manuals
Three complete copies of the Maintenance Manual labeled as described here shall be
submitted to the University for approval in as many three-ring loose-leaf binders as
required. The copies shall be submitted a minimum of two weeks prior to any instructions
and demonstrations to University personnel.
The manuals shall be typewritten and include a table of contents. The information shall be
arranged in a logical order for use by the University in maintaining the project.
The manuals shall include but not be limited to the following:
1. Table of Contents
2. Materials list with place of purchase
3. List of normally replaced items, such as filters, fuses, belts, seals, screens, etc.,
indicating style, rating, size, etc., and place of purchase
4. Installation, servicing, maintenance, and operating instructions for all systems and
components with the place of original purchase and name, address, and phone number
of the person servicing the system
5. Manufacturers’ guarantees and warranties
6. Approved copies of shop drawings, including component wiring diagrams and ATC
wiring piping diagrams of all installed systems indicating all connections, color
coding, functions, locations, and so on. Approved as noted shop drawing submittals
shall be corrected to incorporate all approval notes prior to inclusion in maintenance
manuals.
7. Schedule of all motors, starters, and controllers under this Contract with the following
information included:
December 1998
P. 15-45
DIVISION 15
DESIGN AND CONSTRUCTION STANDARDS
MECHANICAL SYSTEMS
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FACILITIES MANAGEMENT SERVICES
Location
All nameplate data
Overload rating and manufacturer’s number
Actual full-load amperes
Overcurrent protection
8. System and equipment startup, seasonal changeover, and seasonal shutdown with
prestart checklists and precautions
9. System and equipment troubleshooting guides
10. Reference documents that include a construction drawings list, a record set of
drawings list, and test and balance records
11. Testing and balancing procedures for each system and system components
12. Copies of all inspection certificates and approvals from all inspection agencies
13. A copy of an approved balancing report. Where duct leakage has been deemed
critical, test documentation shall be included in the balancing report.
Instruction/Demonstration
Instruction manuals shall be furnished to University personnel a minimum of two weeks
prior to any instructions and demonstrations.
At the completion of the work, the Contractor shall instruct and demonstrate to those
University employees who will have charge of the equipment, the care, adjustment, and
operation of all parts of the system. Such instruction shall cover a minimum period as
determined by the University, eight hours per day, after the University has taken over the
operation of the building, except as mentioned previously, and shall be arranged for at the
University’s convenience.
University maintenance and operations personnel shall be given a minimum two-week
notice of scheduled instruction date.
Startup
The Contractor shall arrange for special startup service from the equipment manufacturer,
or an appointed agent, for the following equipment:
• Chillers
• Pumps
• Cooling towers
• ATC systems
• Boilers
• Air handling units
The startup shall include, but not necessarily be limited to:
• Alignment and balance
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December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
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DIVISION 15
MECHANICAL SYSTEMS
Lubrication
Electrical connections, voltage, rotation
Motor amperage readings
Pump discharge and suction readings
Chiller head and suction readings
Chiller head and suction pressures
Condenser water flow and temperature
Chilled water flow and temperature chiller lock, sequences and safety controls
Water systems
Supervision of flushing and cleaning
Performance of pH readings
University maintenance and operations personnel shall be notified at least two weeks
prior to scheduled startup dates to observe procedures. This does not preclude the
requirements for operating instructions.
Following startup, the manufacturer shall submit a report of findings to the Contractor,
with a copy to the University. If the work is state funded, the report shall also be
submitted to the State Department of General Services.
Testing and Balancing
All testing, adjusting, and balancing (TAB) shall be done in accordance with the National
Environmental Balancing Bureau (NEBB) or Associated Air Balance Council (AABC).
On major construction projects, as determined by the University, the balancing
subcontractors must be NEBB-certified.
Procedures
Environmental systems, including all equipment, apparatus, and distribution systems,
shall be tested and balanced in accordance with the AABC or NEBB procedural
standards. Fume hood testing shall be in accordance with the procedure outlined in the
AABC manual.
All instruments used for measurements shall be accurate, and calibration histories for
each instrument shall be available for examination. Calibration and maintenance of all
instruments shall be in accordance with the requirements of AABC or NEBB.
Accuracy of measurements shall be in accordance with AABC or NEBB standards.
During the operating tests of the chilled water system, the Contractor shall provide, if
necessary, a false load equal to full capacity on the chiller and submit data on gpm flow,
pressure drop, inlet and outlet temperatures of chilled water, amperage of chiller, and
ambient air temperature at condenser.
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DIVISION 15
MECHANICAL SYSTEMS
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
In addition, the Contractor shall check the operation of all automatic temperature control
equipment; verify all thermostat, aquastat, airstat, etc., set-points and operations; and
enlist the aid of the control subcontractor to make necessary adjustment where required.
Reports
Three copies of the final reports shall be submitted on applicable AABC or NEBB
Reporting Forms for review and approval by the Design Consultant and the University
Project Manager.
Each individual final reporting form submitted shall bear the signature of the person who
recorded the data and the signature of the testing and balancing supervisor of the
performing firm.
If more than one certified firm performs the TAB work, all final reports shall be
submitted by that certified firm having managerial responsibility.
Identification of all types of instruments used and their last dates of calibration shall be
submitted with the final report.
The final test report shall include appropriate reference to all problems regarding the
system(s) encountered prior to, during, and after testing and what action was taken to
correct the problem(s), including noise and vibration problems.
Each report shall include a print (or sketch) reduced in size, showing all supply, return,
and exhaust air outlets for easy reference to report data.
An approved copy of the balancing report shall be included in the maintenance manual
submittal.
Fan Sheaves
The fans shall be balanced and the unit sheaves shall be left approximately in the midrange of adjustment. The Contractor shall, where necessary, change the originallyfurnished sheaves to achieve this mid-range adjustment.
It is not acceptable for a balancing contractor to indicate that the system has been
balanced as far as the existing sheaves, etc. as required.
Pressure Vessels
All pressure vessels shall be installed in accordance with the requirements of the
Commonwealth of Pennsylvania, Department of Labor and Industry Code for Unfired
Pressure Vessels.
Tanks and pressure vessels shall be inspected, stamped, and certified to be constructed in
accordance with the above code and the ASME Code for Unfired Pressure Valves.
Operating certificates shall be turned over to the University upon completion of the
project.
P. 15-48
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 15
MECHANICAL SYSTEMS
Acceptance of Completed ATC Installation
Upon completion of the installation, the ATC Contractor shall start up the system
and shall perform all necessary testing and run diagnostics to ensure proper operation,
including piping systems testing and hydrostatic testing. All piping shall be tested prior to
receiving insulation.
Prior to filling the systems, all joints and potential leak sources shall be painted with a
water and powder blue line caulk mixture and allowed to dry. During the test, each joint
shall be visually inspected. The Design Consultant shall specify test pressures.
December 1998
P. 15-49