Design Guidelines and Standards Manual
University of Cincinnati
SECTION 15010D - BASIC MECHANICAL REQUIREMENTS
A.
SECTION INCLUDES
1.
2.
3.
4.
B.
Teamwork
Design Criteria
Energy Conservation
Acoustics
TEAMWORK
1.
Participants:
a.
b.
c.
d.
e.
f.
g.
2.
Major Functions (Not limited to this list)
a.
b.
c.
d.
C.
University Staff
Architect (Principal Coordinator of all Design Disciplines)
Civil Engineer
Electrical Engineer
Mechanical Engineer (HVAC, Plumbing & Fire Protection)
Structural Engineer
Other specialty consultants, as required
Translation of building user’s functional requirements into a n architectural
solution that incorporates the principles of energy conservation.
Coordination of (Continuing process from schematic design through
completion of project):
1.
University Master Plan
2.
Energy Design Elements
3.
Landscaping Design
4.
Engineered systems (building, mechanical, electrical, structural, etc.),
and architectural design.
Selection of systems, materials, and equipment
Design Cost Control: Responsible for on-going cost awareness, impact of
design decisions and prompt reporting of any difficulties to the University.
DESIGN CRITERIA
1.
General
a.
b.
c.
d.
Evaluate utility feed line size to buildings with regard to potential future
growth.
HVAC piping larger than 2-1/2 inches, shall be welded steel.
Piping in utility tunnels shall have aluminum jackets over the insulation.
Indoor Design:
1.
Winter: 72F DB, and 35% RH.
BASIC MECHANICAL REQUIREMENTS
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Design Guidelines and Standards Manual
University of Cincinnati
e.
f.
g.
h.
i.
2.
Plumbing
a.
b.
3.
2.
Summer: 72F, and 50% RH.
Outdoor Design:
1.
Winter: +1F (maximum)
2.
Summer: 92F DB and 73F WB
Occupancy:
1.
6:00 a.m. to 12:00 p.m., unless stated otherwise.
2.
Energy using equipment, serving the occupants, to remain operational
the full 18 hour operation.
3.
Special areas, serving animals, plants, or other research operations
may require 24 hour operation. Coordinate with the University.
Commissioning:
1.
Refer to the University’s Commissioning Standard
2.
The “commissioning plan” shall be developed during schematic
design to allow the proper attention, as the documents are developed.
Design Analysis Procedures
1.
Life Cycle Cost Analysis: Items which provide a return of less than
seven years are to be given a “Value Engineering” review, with
regard to the overall project and the project construction budget.
Evaluation shall be reviewed and coordinated with the University,
before implementing in the design.
Field Quality Control: Proper workmanship and installation of systems and
equipment is essential for energy efficient operation of facilities. It is
important for the designers to make timely visits to the construction site to
verify that construction is proceeding in accordance with the intent of the
design. It is equally important that the specifications adequately address
FIELD QUALITY CONTROL.
Domestic Hot Water
1.
Temperature: 120F. for normal service. Kitchens require 140F.,
and some glass washers and cage washers require 180F water.
Coordinate with the University.
2.
Energy source shall be economically evaluated, considering central
plant steam or electric power (gas is not to be considered).
Compressed Air
1.
Plant compressed air is available from both the East and West Central
Plants. Each building’s compressed air requirement shall be
economically evaluated to determine the most effective approach
(local or central plant).
Heating
a.
Central Utility Steam:
1.
Is generated at two utility plants. The west plant generate steam at
125 psig and the east plant generates 300 psig steam.
2.
The steam is distributed at 125 psig from both plants.
BASIC MECHANICAL REQUIREMENTS
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5/18/2000
Design Guidelines and Standards Manual
University of Cincinnati
Condensate is collected in an 8” main , which connects the two
campuses, and is returned to three different locations. The
condensate is pumped to either the west plant, at elevation 750 ft or
the east plant at elevation 830 ft.
Building Systems
1.
Each building shall have a duplex condensate pump. Since the steam
is generated at high pressure and reduced through pressure reducing
valves, the steam will be superheated. Therefore condensate pumps
must be able to handle 210F water.
2.
Steam supply pressure to each building shall be reduced through, at
least, one duplex reducing station. The valves shall be sized for 1/3
and 2/3 the total load, and with a manual valved bypass.
3.
Steam pressure within a building shall be below 25 psig.
4.
The building interface with the central steam system shall be through
steam to hot water heat exchangers (converters). Each building shall
have dual converter systems, each sized to provide 2/3’s of the
building load. Each of the converter systems shall be capable of
operating independently or together. The converter systems shall be
adequately valved to permit isolation of each pump, each heat
exchanger and each temperature control valve, such that maintenance
or service may be performed on any one of the those items, without
shutting the heating system down.
5.
All 100% outside air heating coils shall be vertical , steam, integral
face and by-pass coils.
6.
Any portion of the building exterior skin (walls or windows) that will
incur a design heat loss in excess of 500 btuh’s per lineal foot, shall
be heated by finned tube radiation or radiant panels.
3.
b.
4.
Cooling
a.
Central Plant Utility Chilled Water:
1.
Is generated at two utility plants. The East Plant, at elevation 782 ft.,
has a static pressure of 95 psig, and the distribution pumps add 85
psig. The West Plant, at elevation 760 ft., has a static pressure of 115
psig, and the distribution pumps add 65 psig. Therefore, the
components in the chilled water system shall be rated at 250 psig
operating pressure.
2.
Temperature of chilled water leaving the plant is 45F and must be
returned to the plant at 58 to 60 F.
3.
Chilled water is available, continuously, when the outside air
temperature is above 45F. The West Plant utilizes a waterside
economizer at outside temperatures between 35 and 45 F; which
permits distribution of chilled water at temperatures that may vary
above 45 F. At outside temperatures below 35 F., central chilled
BASIC MECHANICAL REQUIREMENTS
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5/18/2000
Design Guidelines and Standards Manual
University of Cincinnati
b.
5.
water cooling is terminated and the circulated water temperature will
rise to some thermal equilibrium that may reach 70F.
Building Systems
1.
Building entrance piping shall include a control valve in the return
line, which will respond to system return temperature. The return
temperature shall be managed to utilize the building diversity,
maintain cooling, and optimize the return water temperature. The
building piping shall be configured as a secondary loop, with a
crossover line located on the building side of the control valve (i.e.,
the control valve shall be located in the return line, on the central
system side of the crossover line). This crossover line ( commonly
referred to as a load “de-coupler” ) connects the building load return
line to the suction side of the building pumps, and the central system
supply line ties into the suction side of the building pumps. Refer to
Section 15970 - Controls and Section 15985 - Sequence of Operation,
for instrument description and control sequence.
2.
Where fan-coil systems are to be tied into the central plant system,
they shall be isolated by a plate and frame heat exchanger.
3.
All buildings shall have two chilled water pumps, each sized for
100% of the building load.
4.
Building chilled water pumps larger than 1000 gpm shall be
“horizontal split case” type.
Building Ventilation
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
Each building’s air distribution system shall be served by central station air
handling units, located in either a penthouse or the basement.
Each building shall be served by a minimum of two supply fans and matching
number of return air fans.
Fan type shall be determined by economic evaluation.
Air flow measurement shall be used to track supply, return and outside air
requirements.
Air handling units (AHU) that require a minimum outside air flow, shall have
the outside air intake split into a constant volume outside air section, separate
from the economizer damper section.
Variable Air Volume (VAV) systems are preferred; except in lecture rooms,
where multizone or constant volume systems are required to meet the
ventilation requirements.
Ventilation air handling systems shall be designed to comply with ASHRAE
62 (including latest edition with revisions) standard.
Building air handling units shall be built with access doors between each coil,
filter section and fan section.
There shall be a light in each section of the AHU, with a switch at the door.
AHU filters shall be 65% efficient (minimum), with prefilters; and shall be of
one (same) size throughout the building.
AHU’s with return air, shall have an air blender section.
BASIC MECHANICAL REQUIREMENTS
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Design Guidelines and Standards Manual
University of Cincinnati
l.
m.
n.
o.
p.
q.
r.
s.
D
Air velocity through filters and coils shall not exceed 500 fpm.
Individual chilled water coil height shall not exceed 42 inches.
Humidity may be controlled by a steam grid humidifier, utilizing central plant
steam and a single sensor point. DDC points shall not be cascaded.
Building intakes and exhaust shall be analyzed, so that the design will avoid
re-ingesting contaminated air. Consider location of vehicle exhaust, trash
storage areas and other near-by buildings.
Supply air ductwork shall be designed with external insulation (internal duct
lining is not acceptable), and not to exceed 2700 fpm air velocity.
Noise levels shall not exceed 35 NC. Lecture rooms and other special rooms
may require lower levels, and should be coordinated and verified with the
University.
Each office, lecture room and lab shall be served by an air terminal device
with a reheat coil that is electronically controlled and tied into the campus
wide control system.
Laboratory ventilator shall be 100% outside air, with an air change rate
(ACH) in the range of 8 to 12 changes per hour.
ACOUSTICS
1.
Refer to ASHRAE Handbook “Applications” for design guidance.
2.
Sound Level Criteria
Recommended
Type of Area
a.
b.
c.
RC Design Goals @
Offices
1.
Executive
2.
Conference rooms
3.
Private
4.
Open-plan areas
5.
Computer equipment rooms
6.
Public circulation
25 to 30
25 to 30
30 to 35
35 to 40
40 to 45
40 to 45
Hospitals and clinics
1.
Private rooms
2.
Wards
3.
Operating rooms
4.
Corridors
5.
Public areas
25 to 30
30 to 35
35 to 40
35 to 40
35 to 40
Schools
1.
Lecture and classrooms
2.
Open-plan classrooms
25 to 30
30 to 35 (2) b
BASIC MECHANICAL REQUIREMENTS
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5/18/2000
Design Guidelines and Standards Manual
University of Cincinnati
d.
Libraries
35 to 40
e.
Concert halls
10 to 20 (2) b
f.
Legitimate theaters
20 to 25 (2) b
g.
Recording studios
15 to 20 (2) b
h.
Movie theaters
30 to 35
i.
Animal Quarters
(2) b
j.
Laboratories
45 to 55
1.
2.
3.
E.
All RC ratings should be neutral, e.g. RC 35N. Identical NC (noise
criteria) values may be used when the occupancy can tolerate
background noise that may be somewhat rumbly, hissy or tonal.
Design goals may be increased by 5 points when noise intrusion from
other sources represents a limiting condition.
An acoustical expert should be consulted for guidance on these critical
spaces.
The design goals are the result of a consensus and, in some instances,
may be considered conservative. Depending on subjective response
and economic considerations, they may be increased somewhat where
the noise spectrum is balanced (similar to the slope of an RC rating
curve). Under no circumstances shall the RC exceed the 80 for any
space.
ENERGY CONSERVATION
1.
Energy Efficient Utilization: A primary consideration in the design of new and
renovated facilities.
2.
Comply with OBBC, section “Energy Conservation”.
3.
Evaluate alternative designs in concert with the University Master Plan
other involved design disciplines.
and
END
BASIC MECHANICAL REQUIREMENTS
15010 - D6
5/18/2000