CUSTOM-PACKAGED AIR-HANDLING UNITS
GUIDE SPECIFICATION
This guide is provided by XeteX to assist its sales reps and other specifying agents in preparing design
specifications for purposes of design/build projects. It is based on the broadly-accepted CSI MasterFormat.
Because many construction projects are now being accomplished on a design/build basis rather than hard
bids, a ready source of design options must be available that will satisfy a design engineer’s criteria.
MasterFormat specifications are numbered with 3 pairs of digits, which may be followed by an optional pair.
The first pair of digits indicate the Division, which is Level 1. All HVAC specifications are found in Division
23, which is the first pair of digits. The second pair of digits represents Level 2, followed by the third pair of
numbers, which is Level 3. These three pairs of digits may be followed by an optional 4th pair, used to
expand a Level 3 category.
All HVAC specifications fall under the MasterFormat Division: 23 00 00 Heating, Ventilating, and Air
Conditioning (HVAC). The general description of custom-packaged air-handlers is either “23 73 00 Indoor
Central-Station Air-Handling Equipment” or “23 75 00 Custom-Packaged Outdoor HVAC Equipment”.
Each of these divisions have multiple options that follow, and there are additional CSI MasterFormat
categories for specifying integral equipment in the unit. Examples:
MasterFormat Section 23 72 00 Air-to-Air Energy Recovery Equipment would be used to provide
specifications for Heat-Wheel, Heat-Pipe or Fixed-Plate Air-to-Air Energy Recovery Equipment.
MasterFormat Section 23 76 00 Evaporative Air-Cooling Equipment would be used to provide
specifications for all evaporative cooling hardware.
It will generally be necessary to write specifications for each of the components included in the air
handler. Note that the component specifications may be written either as separate sections in CSI
format (see the attached CSI MasterFormat Division 23 for correct CSI categories) or the component
specifications may be written into this section. When writing separate component specifications,
the written specification must indicate that is intended “for use as a component of the air handler(s)
in Division 23 XX XX of this document.”
When using this guide, many of the available options are shown in red and in brackets [ ]. Simply delete the
items that do not apply and remove the brackets. Change the color to black.
Text in this guide that is in blue and in parenthesis is optional information for the writer of the specification. It
should be deleted.
XeteX disclaimer: This copyrighted document is provided for use by all XeteX sales reps and other
specifying agents. Since the HVAC industry continues to evolve rapidly, certain data will become outdated
with time. XeteX assumes no responsibility nor liability resulting from the use of this document.
Specification Guide for Writing Section 23 75 00 Custom-Packaged, Outdoor, Central-Station AirHandling Units and 23 73 23 Custom Indoor Central-Station Air Handling Units.
Within Section 23 75 00 there are four sub-categories:
23 75 13
23 75 16
23 75 23
23 75 33
Custom-Packaged, Outdoor, Central-Station Air-Handling Units
Custom-Packaged, Rooftop Air-Conditioning Units
Custom-Packaged, Heating and Ventilating Makeup-Air Units
Custom-Packaged, Outdoor, Heating and Cooling Makeup Air-Conditioners.
The descriptor often does not adequately describe the product needed. In that case, choose the category
that is less than adequate but is still completely correct. Take the (correct but inadequate) CSI number and
add the additional requirements to the descriptor. Descriptors may have additions made, but existing
elements may not be taken away.
Descriptors are written in a form that provides a thumbnail description of the needed product. They list the
most important elements first, followed in declining order of importance by additional elements. In other
words,
Division 23 __ __ of the CSI numbering system is for HVAC products.
Section 23 75 __ is for Custom-Packaged Outdoor HVAC equipment.
Section 23 75 33 is for Custom-Packaged, Outdoor, Heating and Cooling Makeup Air-Conditioners.
Example: the design engineer needs a Custom-Packaged, Rooftop Air-Conditioning Unit, but also wants
indirect gas heat and energy recovery. In this case, use the CSI number 23 75 16, but add 2 digits to the
number to indicate it has been expanded. This would make the CSI category: 23 75 16.01 CustomPackaged, Rooftop Air-Conditioning Unit with Indirect Gas-Fired Heat and Energy Recovery. (This
descriptor should list all the hardware options required.)
[Note that the entire CSI category of 23 75 00 is for “Custom-Packaged Outdoor HVAC Equipment”. For any
custom-packaged air handler that is to be installed indoors, the first CSI category number that is completely
correct is 23 73 23 Custom Indoor Central-Station Air Handling Units.
Example: the design engineer needs a custom Indoor Central Air-Conditioning Unit but also needs Energy
Recovery. Use the existing CSI number 23 73 23 and add the additional requirements.
23 73 23 Custom Indoor Central-Station Air Handling Units will become:
23 73 23.01 Custom Indoor Central-Station Air Handling Units with Energy Recovery. (This descriptor
should list all the hardware options required).
Writing a Custom Air Handler Specification
Specification Heading and Descriptor
CSI MasterFormat Number: Determine the correct MasterFormat division number and provide a
descriptor. The first two digits will always be 23, indicating Division 23, Heating, Ventilating and Air
Conditioning.
The second two digits will be either 73 or 75. If the unit is a custom indoor air handler, use 73. If the
unit is a custom outdoor air handler, use 75.
If it is an Indoor Unit, indicate section 23 73 23 Custom Indoor Central-Station Air Handling Units.
Add the additional custom functions or hardware required to the descriptor and add two additional
digits to the number code. Example:
23 73 23.01 Custom Indoor Central-Station Air Handling Units with Heating, Cooling and Energy
Recovery
If it is an Outdoor Unit, select the description that best matches the needed equipment and is
completely correct:
23 75 13 Custom-Packaged Outdoor, Central-Station Air-Handling Units
23 75 16 Custom-Packaged, Rooftop Air-Conditioning Units
23 75 23 Custom-Packaged, Outdoor, Heating and Ventilating Makeup-Air Units
23 75 33 Custom-Packaged, Outdoor, Heating and Cooling Makeup Air-Conditioners
Add the additional custom functions or hardware required to the descriptor and add two additional
digits to the number code. Example:
23 75 13.01
Custom-Packaged Outdoor, Central-Station Air Handling Unit with Heating, Cooling and Energy
Recovery
PART 1 – GENERAL
1.1 DESCRIPTION: Provide a brief description of the needed product. Example:
This is a self-contained, custom-packaged [100% outdoor air] [mixed air] [self-contained] [indoor]
[outdoor] air handler having an indirect-fired gas duct heater, DX cooling and a heat wheel. It is to be
installed on a rooftop [on a curb provided and installed by this contractor]. [It is to be controlled by an
integral Direct Digital Control (DDC) controller.]
1.2 REFERENCES:
The provided equipment must comply with or meet the requirements of the following regulatory
organizations, regulations or standards:
AHRI 260 Sound Rating of Ducted Air Moving and Conditioning Equipment.
AHRI 430 Standards for Central Station Air Handling Units.
AHRI 920 Performance Rating of DX – Dedicated Outdoor Air System Units.
AHRI 1060 Performance Rating of Air-To-Air Energy Recovery Ventilation Heat Exchangers.
AMCA 500-D
Laboratory Methods of Testing Dampers & Louvers for Rating.
ANSI Z83.4
Non-Recirculating Direct Gas-Fired Heating and Forced Ventilation
Appliances For Commercial and Industrial Application.
ANSI Z83.8
Gas Unit Heaters, Gas Packaged Heaters, and Gas Utility Heaters.
ANSI/UL 900
Standard for Air Filter Units.
ASHRAE 52.2
Method of Testing General Ventilation Air-Cleaning Devices for
Removal Efficiency by Particle Size.
ASHRAE 62.1
Ventilation for Acceptable Indoor Air Quality
ASHRAE 84
Method of Testing Air-to-Air Heat/Energy Exchangers
ASHRAE 90.1
Energy Standard for Buildings Except Low-rise Residential Buildings.
ASTM B209
Aluminum and Aluminum Alloy Sheet and Plate.
ASTM E-84
Surface Burning Characteristics of Building Materials.
CSA 2.6
Gas Unit Heaters, Gas Packaged Heaters, and Gas Utility Heaters.
CSA 3.7
Non-Recirculating Direct Gas-Fired Heating and Forced Ventilation
Appliances For Commercial and Industrial Application.
CSA C22.2
Heating and Cooling Equipment.
NEMA
National Electrical Manufacturers Association.
SMACNA
HVAC Duct Construction Standards, 3rd Edition – 2005.
SMACNA
HVAC Air Duct Leakage Test Manual.
UL 181
Mold Growth and Humidity Test.
UL 1995
Heating and Cooling Equipment.
1.3 SCOPE: Describe the scope of the project. If there is more than one air handler, it should be indicated
here. Example:
Provide a self-contained unit designed and manufactured to meet the specific requirements of this
project.
1.3.1 SUMMARY: Provide a summary of the needed product. Show all the included elements of the
product. Example:
This section includes the specified unit with the following components and accessories:
1.3.1.1 [Indirect-Fired duct heater, [meeting specifications found in Section 23 55 13.16 Gas-Fired
Duct Heaters.]]
1.3.1.2 [Heat-Wheel Air-to-Air Energy Recovery Equipment, [meeting specifications as shown in
Section 23 72 13, Heat-Wheel Air-to-Air Energy-Recovery Equipment of this document.]]
1.3.1.3 [DDC controller, [meeting specifications as shown in Section 23 09 23 Direct-Digital Control
for HVAC.]]
1.3.1.4 [List additional hardware here.] (see the attached CSI MasterFormat list of section numbers
and titles for a complete list of appropriate specification numbers.)
1.4 QUALITY:
1.4.1 Components not manufactured in-factory shall be provided by manufacturers familiar to the
HVAC industry.
1.4.2 Unit shall be built in [1] [2] [3] [4] [5] [6] [7] sections or less. All units shipped in separate sections
or modules shall have [manufacturer] [factory authorized contractor] for on-site supervision. Rigging
and setting of units shall be performed by installing contractor. Field installed items including [gaskets]
[trim shields] [seam caps] [flashing] [ventilation hoods] shall be provided by manufacturer and installed
by manufacturer or factory licensed contractor. All field refrigeration piping or connections shall be
completed by factory personnel or factory licensed contractor including line evacuation, leak testing and
refrigerant charging. Units shall ship with a [one] [two] [three] [four] [five] year manufacturer warranty on
all parts.
1.4.3 Performances of all heating and cooling coils shall be certified by AHRI.
1.4.4 Unit construction shall comply with the ASHRAE 62.1 Standard or local building codes,
whichever takes precedence.
1.5 DELIVERY, STORAGE AND HANDLING:
1.5.1 Units shall be shipped with [integral lifting lugs welded to; formed metal lifting lugs extended from;
removable lifting lugs connected to] unit frame. Before leaving factory, all units and extra pieces shall
be wrapped, packaged, and sufficiently protected for transportation by truck and stored outside. Duct
connections shall be covered with wood to prevent ingress into unit. Lifting of equipment must use
spreader bars and must follow manufacturers lifting instructions.
1.5.2 Unit should be immediately inspected for any damages that may have occurred during
transportation by the installing contractor upon arrival. Care should be used when handling the unit to
avoid damaging any components, wiring or surface finish.
1.5.3 If unit is not to be immediately installed, unit shall be stored in a dry place protected from
weather, traffic and unauthorized personnel.
1.5.4 If unit is to be stored for any length of time, it shall be supported and cribbed along the full length
of the support channel and frame. Major support should be provided at the perimeter of unit and at the
furnace and coil sections. The unit can be supported on the angle iron perimeter frame but should not
be supported where there is no additional framing present underneath.
1.5.5 If unit is not to be installed and run immediately, the components should be inspected monthly. If
blower bearings require grease, the grease should be replaced monthly to prevent accumulation of
moisture. A Storage Maintenance Schedule is to be provided in the unit IOM.
1.6 OPERATIONAL REQUIREMENTS:
1.6.1 Unit shall be operated only after all components are tested, ducts connected and cleaned, and
filters installed. Unit shall only be run in its designed position, operating elsewhere can cause damage
and harm to unit and surrounding area.
1.7 APPROVED MANUFACTURERS:
1.7.1 Only manufacturers that specialize in production of self-contained packaged equipment and have
a minimum of [ten (10)] years of experience are approved to provide the specified equipment for this
project.
1.7.2 The following manufacturers are approved for this project, provided that they meet all of
the requirements of this specification:
1.7.2.1 XeteX
1.7.2.2 Aventus
1.7.2.3 [List of other manufacturers]
1.7.2.4 [Energy Labs]
1.7.2.5 [Haakon]
1.7.2.6 [Venmar]
1.7.2.7 [TMI Climate Solutions]
1.8 SUBMITTALS:
Submit shop drawings and product performance data for all components listed in this section and for all
integral components specified in other sections.
1.8.1 Drawings shall include accurately scaled CAD drawings of entire unit with plan and elevation
views. Any required sectioning shall be clearly noted and shown on all views.
1.8.2 Drawings shall include a schedule of required clearances for installation of the unit.
1.8.3 All technical data relevant to the provided unit shall be submitted including, but not limited to, all
data shown in the schedules accompanying the specification. The manufacturer shall note any
variances in scheduled performance data and/or other specified requirements.
1.8.4 Product performance data shall include unit dimensions, weights, capacities, component
performance data, electrical data, construction details, required clearances and service access
dimensions, field connection requirements and locations, total pressure drop within unit, included
gauges and sensors, performance of each blower, unit construction materials, and surface finish.
1.8.5 Performance data of each blower shall include performance curves showing the operating
condition as described on schedule. Sound power level at each octave shall also be included for each
blower.
1.8.6 Performance data for coils shall include selection sheets showing entering conditions, altitude, air
density, [glycol concentration,] fluid flow rate, fluid pressure drop, and leaving air conditions.
1.8.7 Performance shall include [EER] [IEER] [ISMRE] [MRE] [COP] at the designed unit operating
state.
1.8.8 The submittal shall contain detailed information about all drain connections, drain
locations, trap heights, piping and electrical chases, and all duct connections.
1.8.9 Submittal shall provide information on filters including pressure drop, efficiency, media
description, frame details, and filter gauge information.
1.8.10 Submittals shall include the recommended installation design and instructions from the
manufacturer.
1.8.11 Electrical data for each unit shall be included with full load amps for each component, maximum
circuit ampacity, breaker and disconnect sizing, transformer size, and wiring diagrams for the control
panel and complete unit wiring. Wiring diagram shall also include information of factory wired and field
wired components.
1.8.12 Omission of any of the above will result in an immediate return of submittal material without
review or consideration.
1.9 EXTRA MATERIALS:
Manufacturer shall provide [1] [2] [3] [X] total sets of [filters] [belts] [bulbs] [fuses]
PART 2 - UNIT SPECIFICATION
Manufacturer shall provide an [indoor] [outdoor] unit that is mounted on a [curb] [dunnage] [pad], in
accordance with the construction schedule. Unit shall include [supply and exhaust blowers] [EC motors]
[motors with VFDs] (see Section 23 34 XX for CSI specifications) [final filters] [low leakage shut off
dampers] [insulated shut off dampers] (see Section 23 33 13 Dampers for CSI specifications) [heatwheel air-to-air energy recovery unit] (see section 23 72 13 for CSI specifications) [sensible fixed-plate
air-to-air energy recovery unit] [enthalpic fixed-plate air-to-air energy recovery unit] (see Section 23 72
19 Fixed-Plate Air-to-Air Energy-Recovery Equipment for CSI specifications) [indirect-fired gas burner]
[direct-fired gas burner] (see section 23 55 13 Fuel-Fired Duct Heaters for CSI specifications); [fully
packaged direct expansion system] [...]
2.1 CABINET CONSTRUCTION
2.1.1 Unit Casing Performance
2.1.1.1 Leakage shall not exceed 1% of the rated unit CFM at +/- [6”] [8”] [10”] static pressure.
2.1.1.2 Panel deflection shall not exceed L/240 of panel length at +/- [6”][8”][10”] static pressure.
2.1.1.3 Casing insulation shall possess an R-value rating of [3.5/in] [4.0/in] [5.7/in] [6.9/in] of
insulation at center of panel.
2.1.1.4 [1”] [2”] [3”] [4”] [fiberglass] [mineral wool] [poly-iso foam board ] [injected foam] [thermal
break] [non-thermal break] walls shall be constructed with interior and exterior metal surfaces.
Other types of insulation will not be accepted. (see Section 23 07 16 HVAC Equipment Insulation
for CSI specifications)
2.1.1.5 Interior liner shall be [galvanized] [aluminum] [stainless steel] with a minimum thickness of
[GALV:] [16ga] [18ga] [20ga] [22ga] [ALUM:] [0.063”] [0.080”] [SS:] [16ga] [18ga] [20ga]. [Interior
shall also contain sound dampening material to reduce sound reverberations in [all fan sections]
[supply fan sections].]
2.1.1.6 Unit construction shall utilize insulation in all panels, posts, and corners. Casings that have
hollow portions and inconsistent R-values are not acceptable and will be rejected.
2.1.1.7 Exterior construction shall be [galvanized] [galvannealed] [aluminum] [stainless steel] with a
minimum thickness of [GALV:] [16ga] [18ga] [20ga] [ALUM:] [0.063”] [0.080”] [SS:] [16ga] [18ga]
[20ga]. Finish painted exterior shall bear an ASTM D5894 and D522 certification that is also ASTM
salt spray tested to 1250 hours or greater.
2.1.1.8 All joints shall be sealed with a high grade polyether sealant or silane modified polymer
(SMP) Adhesive Sealant conforming to ASTM C920, Type S, Grade NS, Class 50, Use T, NT, I, G
and A. AAMA 802.3 Type II Back Bedding Compound. USDA approved. [Silicon not acceptable].
2.1 ROOFS
2.1.1 Construction of the roof shall be identical to wall construction specified.
2.1.2 Unit roof for outdoor units shall be sloped to a minimum pitch of ½” per foot.
2.1.3 Roof shall have rain deflectors along all sides to prevent water streaming on unit walls.
2.1.4 Roofs greater or equal to 60” shall be peaked in the center and sloped to both sides of the unit
with a cap over the seam. Roofs less than 60” shall be sloped away from unit access.
2.1.5 Roof shall accommodate a minimum snow load of 30lbs per square foot with a total roof capacity
no less than 300lbs load for service and maintenance.
2.1.6 Outdoor roofs that are not sloped will not be accepted.
2.1.7 All outdoor roof duct connections shall be provided with a 1.5” duct flange above roof.
2.2 INSPECTION AND UNIT ACCESS DOORS:
2.2.1 Panels and doors shall be constructed of double-wall, [1”] [2] [3”][4”] injected foam insulated
panels.
2.2.2 All access doors shall use aluminum [thermal break] extrusion frame.
2.2.3 Hinges shall be full height stainless steel piano style.
2.2.4 Door handles shall be glass fiber reinforced, UV rated, nylon polyamide handle with roller cam
latches to ensure proper compression.
2.2.5 All unit doors shall be installed to open against internal section operating pressure. Units will not
be accepted if doors are hinged incorrectly.
2.2.6 [Testing ports shall be included in door locations as required to measure pressure drop across
[critical components; all access doors]. [Ports shall be thermally broken with an integrated screw-on
cap.]
2.2.7 [A door rain deflector shall be provided above all access doors and made from same material as
the exterior casing.]
2.2.8 [Door interlock switches shall be provided with a minimum NEMA 3R rating on all doors noted on
submittal drawing. Switches shall be a single pole double throw with a sealed roller plunger actuator.]
2.3 UNIT FLOOR:
2.3.1 Floor shall be constructed with minimum [16ga] [14ga] [12ga] [galvanized steel] [aluminum]
[stainless steel] [tread plate] with [2”] [3”] [4”] [foam] [mineral wool] insulation. All panels shall be
caulked and sealed to base.
2.3.2 Floor shall be thermally isolated from the welded base frame members. Construction without a
thermally isolated floor shall not be accepted. Floor panels shall also be constructed to prevent oil
canning.
2.3.3 [Floor shall have an upturned lip with fully welded seams capable of holding 2” of water.
Penetrations through floor other than those noted in submittal shall not exist. Construction allowing
screws or bolts to penetrate the floor shall not be allowed. Each section shall be capable of retaining a
minimum of 1 ½” of water without leakage.]
2.3.4 All internal equipment shall be a minimum 2 inches from floor for housekeeping.
2.3.5 All floor openings shall have support around entire perimeter.
2.3.6 Over all openings in the floor, [fiberglass] [stainless steel] [galvanized] floor grates shall be
provided by factory for final installation.
2.4 UNIT FRAME AND BASE RAIL:
2.4.1 Unit shall be mounted on a [3”] [4”] [5”] [6”] [8”] tall structural [steel c-channel] [aluminum cchannel] [angular iron] with cross supports spaced at regular intervals. The frame shall be provided with
[welded] [removable] [extended] lifting lugs. Manufacturer shall provide curb angle welded to the base
for outdoor curb mounted units.
2.4.2 Entire unit frame shall be continuously welded at each intersection. Spot welded or tack welded
frames shall not be accepted and will be rejected.
2.4.3 [Unit Base frame shall be fully assembled in factory and sectioned per unit drawing. Welded base
frame sections shall be moved to location and rejoined by contractor.]
2.5 CONDENSATE DRAIN PAN:
2.5.2 Drain pans shall comply with Standard ASHRAE 62.1
2.5.3 Drain pans shall be provided in all cooling coil, humidifier, energy recovery or any other
component with the likelihood for water droplet fallout.
2.5.4 All pans shall be double sloped and pitched towards a MPT drainage connection. Underside of all
pans shall be insulated with a dense spray urethane to prevent condensation.
2.6 ENERGY RECOVERY
2.6.1 [Unit shall be supplied with a sensible flat plate heat exchanger.] [General requirements for the
flat plate heat exchanger are:] (see CSI Division 23 72 19)
2.6.1.1 Flat plate heat exchanger shall meet or exceed performance scheduled on drawings.
2.6.1.2 Provide heat exchanger with a maximum face velocity as scheduled. Face velocity
calculations shall be based on the finned area of the exchanger.
2.6.1.3 The plates of the exchangers shall be [aluminum] [stainless steel]. Plates made from
aluminum alloys, carbon steel, plastic, fiber or other material(s) will not be accepted. Exchanger
shall be constructed with (CAN PICK MULTIPLE) [powder coated frame] [epoxy coated plates]
[closed cutting edges] to protect from corrosion.
2.6.1.4 Drain Pans shall be double sloped construction and in compliance with ASHRAE 62.1.
2.6.1.5 Heat exchanger shall be a cross flow arrangement.
2.6.1.6 Performance data derived from laboratory testing or heat exchanger conditions shall be in
accordance with ASHRE Standard 84. Performance shall be rated with AHRI Standard 1060 testing
procedures.
2.6.1.7 The sensible plate exchanger shall be listed in the AHRI Certified Product Directory. The
exchanger shall bear the AHRI Certified Product Seal.
2.6.1.8 Sensible effectiveness, pressure drop, exhaust air transfer ratio (EATR) and outside air
correction factor (OACF) ratings shall be clearly documented with performance testing conducted in
accordance with ASHRE Standard 84 and AHRI Standard 1060.
2.6.1.9 EATR shall be certified 0.1% at differential pressures up to 1.6” in.w.g.
2.6.1.10 Plates shall be die formed with positive/negative dimple stamping that provides a
discontinuous channel design. Plate profiles that produce laminar flow shall not be accepted.
2.6.1.11 Plate heat exchanger shall be assembled into a strong, self-supporting frame made of
aluminum corner extrusions and 20 gauge galvanized steel endplates. Endplates shall be insulated
for winter frost control.
2.6.1.12 Plate heat exchanger shall withstand a pressure differential of 7.2”w.g. without significant
change in its performance or pressure drop. Sensible heat exchanger shall withstand temperatures
up to 190°F.
2.6.1.13 The unit shall have minimum 2" MERV 8 filters for the outdoor and return air paths before
the flat plate to keep plates clean and reduce maintenance.
2.6.2 [Unit shall be supplied with a flat plate heat exchanger capable of transferring sensible and latent
energy. General requirements for enthalpy flat plate heat exchanger are:] (see CSI Division 23 72 19)
2.6.2.1 Flat plate heat exchanger shall meet or exceed performance listed on unit schedule.
2.6.2.2 Enthalpy flat plate shall have no moving parts and shall be used in a crossflow orientation.
Airflow channels shall be composed of a 100% polymer membrane coated substrate. Exchanger
shall be assembled into a strong, self-supporting frame made of aluminum extrusions and
aluminum sheet endplates. Endplates shall be insulated for winter frost control.
2.6.2.3 Sensible effectiveness, latent effectiveness, total effectiveness, pressure drop, exhaust air
transfer ratio (EATR) and outside air correction factor (OACF) ratings shall be clearly documented
with performance testing conducted in accordance with ASHRE Standard 84 and AHRI Standard
1060.
2.6.2.4 Exchanger shall have an EATR of less than 0.5% at 1” in.w.g. as tested to AHRI 1060.
2.6.2.3 Exchanger shall not degrade or promote growth of mold and bacteria.
2.6.2.4 Heat exchanger shall be able to tolerate temperatures between -22°F to 140°F without
increasing EATR or decrease performance. Exchanger shall be freeze tolerant to 150 freeze thaw
cycles while maintaining 0.5% EATR.
2.6.2.5 The unit shall have minimum 2" MERV 8 filters for the outdoor and return air paths before
the flat plate to keep plates clean and reduce maintenance.
2.6.2.6 Exchanger shall be flame proof and comply with UL 723 with a flame spread index no more
than 25 and smoke index less than 50.
2.6.2.7 [Unit shall be provided with a full face and bypass damper capable of 100% air bypass]
2.6.3 [Unit shall be supplied with a rotary heat exchanger capable of transferring sensible and latent
energy. General requirements for the rotary wheel heat exchanger are: (see CSI Division 23 72 13)
2.6.3.1 Rotary heat exchanger shall meet or exceed performance listed on unit schedule.
2.6.3.2 Heat exchanger shall be provided with a maximum face velocity less than 1000 feet per
minute. Face velocity calculations shall be based on the fluted area of the exchanger.
2.6.3.3 Performance data derived from laboratory testing or heat exchanger conditions shall be in
accordance with ASHRE Standard 84. Performance shall be rated with AHRI Standard 1060 testing
procedures.
2.6.3.4 The wheel exchanger shall be listed in the AHRI Certified Product Directory. The
exchanger shall bear the AHRI Certified Product Seal.
2.6.3.5 Sensible effectiveness, latent effectiveness, total effectiveness, pressure drop, exhaust air
transfer ratio (EATR) and outside air correction factor (OACF) ratings shall be clearly documented
with performance testing conducted in accordance with ASHRE Standard 84 and AHRI Standard
1060.
2.6.3.6 [Rotary heat exchanger shall include a purge section to reduce amount of air crossover.]
2.6.3.7 Exchanger shall utilize a permanently bonded 3 angstrom molecular desiccant sieve.
Wheel depth shall be a minimum of 8” (200 mm) in depth to provide high efficiency and
effectiveness.
2.6.3.8 The unit shall be provided with an AHRI certified rotary wheel air-to-air heat exchanger in a
cassette frame complete with seals, drive motor and drive belt. The energy recovery wheel shall be
an integral to unit air handler. Bolt-on energy recovery units that require field assembly and section
to section gasketing, and sealing are not acceptable.
2.6.3.9 The wheel performance, pressure drop, and effectiveness shall be AHRI certified per AHRI
Standard 1060.
2.6.3.10 The unit shall have minimum 2" MERV 8 filters for the outdoor and return air paths before
the wheel to help keep the wheel clean and reduce maintenance.
2.6.3.11 The matrix design shall have channels to reduce cross contamination between the outdoor
air and the exhaust air. All diameter and perimeter seals shall be provided as part of the cassette
assembly and shall be factory set. Drive belt(s) of urethane shall be provided for wheel rim drive
without the need for external tensioners or adjustment.
2.6.3.12 Wheel frame construction shall be a welded hub, spoke and rim assembly of stainless,
plated and/or coated steel and shall be self-supporting.
2.6.3.13 Wheel bearings shall be selected to provide an L-10 life in excess of 200,000 hours.
Wheels shall be connected to the shaft by means of taper lock hubs.
2.6.3.14 [The control of the energy recovery wheel shall be an integral part of the air handler unit’s
DDC controller. The DDC controller shall have visibility of the outdoor air temperature, leaving
wheel temperature, return air temperature, and exhaust air temperature. These temperatures shall
be displayed at the air handler’s DDC controller LCD display. All of these temperatures shall be
made available through the BACnet interface.]
2.6.3.15 [The air handler unit with the energy recovery wheel shall incorporate the economizer
operation. The energy recovery wheel shall have a bypass damper. When the unit is in the
economizer mode of operation the energy recovery wheel shall stop and the bypass dampers shall
be opened. The outdoor air shall be drawn through the bypass dampers to reduce the pressure
drop of the outdoor airstream.]
2.6.3.16 [The air handler unit’s DDC controller shall provide frost control for the energy recovery
wheel. When a frost condition is encountered the unit controller shall stop the wheel. When in the
frost control mode the wheel shall be jogged periodically and not be allowed to stay in the stationary
position.]
2.6.4 [Unit shall be supplied with a desiccant wheel for dehumidification. General requirements for the
rotary wheel heat exchanger are:] (see CSI Division 23 72 13)
2.6.4.1 Rotary heat exchanger shall meet or exceed performance listed on unit schedule.
2.6.4.2 Heat exchanger shall be provided with a maximum face velocity less than 1000 feet per
minute. Face velocity calculations shall be based on the finned area of the exchanger.
2.6.4.3 Desiccant wheel shall be a high capacity desiccant captivated in a perimeter band with 10
radial spokes. Cassette shall be designed for 10 years of continuous use with minimal
maintenance. Cassette shall be composed of corrugated fiberglass with no more than 4% of the
media being organic.
2.6.4.4 Desiccant wheel media shall be capable of withstanding spot temperatures of up to 2,000
degrees F without mechanical failure. This is a safety feature, intended to mitigate damage in the
event of a gas-fired duct heater over-firing.
2.6.4.5 Rotor media shall comply with ASTM E-84 and tested with ASHRAE guidelines for
performance.
2.6.4.6 Wheel shall be driven by a tensioned timing belt or a drive sprocket and chain.
2.6.4.7 All seals shall be made of a high temperature rubber to ensure positive sealing.
2.6.4.8 Heat exchanger shall be 304 stainless steel for both the frame and face panels.
2.7 AIR FILTRATION (see CSI Division 23 41 00)
General Requirements for Air Filtration Section:
2.7.1 Provide a minimum efficiency reporting value (MERV) according to ASHRE 52.2.
2.7.2 Filter segments shall be provided with filters and frames as scheduled and shall not exceed a
face velocity of [300] [400] [500] [600] feet per minute.
2.7.3 Provide filter holding frames arranged for flat or angled orientation with access doors as indicated
on drawings. Filters shall be accessible from minimum one side or removable from an access plenum.
2.7.4 Filter racks shall be constructed from [galvanized steel] [stainless steel] [aluminum] [with
retention clips].
2.7.5 Filter media shall be in compliance with UL 900 Standards.
2.7.6 [MERV 8 (20%), [2”] [4”]]
2.7.6.1 [Filter shall be constructed of high strength beverage board frame treated with a water
resistant coating. Filter media shall be bonded to metal grid to promote rigidity and shall
have 15 pleats per foot or more.]
2.7.7 [MERV 11 (65%), [4”] [6”] [12”]]
2.7.7.1 [Filter shall be constructed of a recycled plastic frame with plastic struts that allows for a
ridged and light weight frame. Filter media shall be a high efficiency synthetic that doesn’t rely upon
electrostatic charge to increase efficiency. Media shall be bidirectional and oriented in a [single, flat
panel] [v-bank] [multi panel] configuration.]
2.7.8 [MERV 13 (85%), [2”, 4”, 6”, 12”] (choose ONE of the following options:)
2.7.8.1 [Filter shall be constructed of high strength beverage board frame treated with a water
resistant coating. Filter media shall be synthetic and bonded to metal grid to promote rigidity and
shall have 15 pleats per foot or more.]
2.7.8.2 [Filter shall be constructed of a recycled plastic frame with plastic struts that allows for a
ridged and light weight frame. Filter media shall be a high efficiency synthetic that doesn’t rely upon
electrostatic charge to increase efficiency. Media shall be bidirectional and oriented in a [single, flat
panel] [v-bank] [multi panel] configuration.]
2.7.9 [MERV 14 (95%), [4”] [12”]]
2.7.9.1 [Filter shall be constructed of a recycled plastic frame with plastic struts that allows for a
ridged and light weight frame. Filter media shall be a high efficiency synthetic that doesn’t rely upon
electrostatic charge to increase efficiency. Media shall be bidirectional and oriented in a [single, flat
panel] [v-bank] [multi panel] configuration. Filter shall withstand temperatures of 160°F.]
2.7.10 [MERV 15 (95%), [6”] [12”]]
2.7.10.1 [Filter shall be constructed of a recycled plastic frame with plastic struts that allows for a
ridgid and light weight frame. Filter media shall be a high efficiency synthetic that doesn’t rely upon
electrostatic charge to increase efficiency. Media shall be bidirectional and oriented in a [single, flat
pane] [ v-bank] [multi panel] configuration. Filter shall withstand a burst strength of + [8] [25] in.w.g.
and temperatures of 160°F.]
2.7.11 [MERV 16 (95%),12”]
2.7.11.1 [Filter shall be constructed of a recycled plastic frame with plastic struts that allows for a
ridged and light weight frame. Filter media shall be a high efficiency synthetic that doesn’t rely upon
electrostatic charge to increase efficiency. Media shall be bidirectional and oriented in a [single, flat
panel; v-bank, multi panel] configuration. Filter shall withstand a burst strength of + 25 in.w.g. and
temperatures of 160°F.]
2.7.12 [HEPA 12” [99.7%] [99.9%] [99.99%]]
2.7.12.1 [Filter shall be constructed of a polyurethane sealed extruded aluminum frame with a
manufacturer installed [two-part gel seal; minimum 0.25” neoprene gasket]. Filtration media shall be
constructed with moisture resistant glass microfibers with aluminum separators for support and air
resistance. Filter shall withstand a minimum of 250°F.]
2.7.13 [Aluminum Mesh (MERV 8, 20%), [1”] [2”] [3”] [4”]]
2.7.13.1 [Filters shall be a water washable metal mesh constructed out of [aluminum] [galvanized]
[stainless steel] for both filter media and frame. [Aluminum filters shall be able to withstand
temperatures of 250°F] [Galvanized filters shall be able to withstand temperatures of 450°F]
[Stainless steel filters shall be able to withstand temperatures of 900°F].]
2.8 FANS (see CSI Division 23 34 00)
2.8.1 All fan curves shall be provided with specified operating point clearly plotted.
2.8.2 Fans shall be balanced to mitigate vibration.
2.8.3 [Fan assembly shall be mounted on [1” spring] [2” spring] [1” restrained spring] [2” restrained
spring] [1” seismic spring] [2” seismic spring] isolators for reduction of noise and vibration to building.]
2.8.4 Fans shall be arranged in [a single] [an array] fan configuration.
2.8.5 All fans shall be [directly driven] [belt driven] by a premium [inverter duty] efficiency motor. Motors
shall be [open drip proof] [totally-enclosed, fan cooled] [electronically commutated] [explosion proof] in
design [with grounding rings].
2.8.6 Fan impellers shall be [a plenum type backwards curved airfoil] [a plenum type backwards
inclined airfoil] [a plug style backwards curved airfoil] [a double width, double inlet housed backwards
curved airfoil] [a double width, double inlet housed backwards inclined airfoil] [a double width, double
inlet housed forward curved airfoil] [a single width, single inlet housed backwards curved airfoil] [a
single width, single inlet housed backwards inclined airfoil] [a single width, single inlet housed forward
curved airfoil] and constructed out of [steel] [aluminum] [composite].
2.9 COILS
2.9.1 [Water Coils]
2.9.1.1 Water coils shall be provided in compliance with AHRI Standard 410. Coils shall be rated to
pressures of 150 psig. All coils shall be manufacturer-tested to at least 315 psi while submerged in
water.
2.9.1.2 Water coils must be leak-tested by means of applying a minimum of 5 psig compressed
nitrogen after coil installation and then must be left with a 5 psig charge of compressed nitrogen for
shipment.
2.9.1.3 Coils shall meet or exceed scheduled performance [with XX.X% [propylene] [ethylene]
glycol]].
2.9.1.4 Fins shall be a plate-fin design using [aluminum] [copper] that cover entire tube surface
with self-spacing collars. Fin surface shall be a formed [flat] [waffle] [sine-wave] to provide superior
energy transfer. Fin thickness shall be [0.0075”] [0.0060”] and available in a uniform density
between 6 to 14 fins per inch.
2.9.1.5 Tubing and return bends shall be constructed from UNS 12200 seamless copper and
annealed with a maximum grain size 0.040 mm. Tubes shall be mechanically expanded into fins to
form an interference fit.
2.9.1.6 Headers shall be constructed from UNS 12200 copper. Header end caps shall be dieformed and installed on the inside diameter of header such that the landed surface is three times
the header wall thickness. Coils shall be equipped with a factory installed air vent located at the
highest point available on the header.
2.9.1.7 Coil casing and endplate shall be fabricated from [galvanized steel] [aluminum] [304
stainless steel] [316 stainless steel]. All tube sheet cutouts shall be oversized to allow for free
thermal expansion. Coils 50 inches or greater shall be fabricated with intermediate tubing supports
constructed of same material and gauge of end plates.
2.9.1.8 All coils shall be brazed with a filler material that is a minimum 5% silver in joining header
and core tubes.
2.9.1.9 [Coils shall be provided with a corrosion resistant [e-coat] [electrofin] [epoxy] [Blygold]
coating.]
2.9.2 [Steam Coils] (see CSI Division 23 82 16.12)
2.9.2.1 Steam heating coils shall be provided in compliance with AHRI Standard 410. Coils shall be
safety listed to withstand supplied saturated steam pressures of 350 psig or more. All coils shall be
manufacturer tested to at least 315 psi while submerged in water.
2.9.2.2 Fins shall be a plate-fin design using [aluminum] [copper] that cover entire tube surface
with self-spacing collars. Fin surfaces shall be a formed [flat] [waffle] [sine-wave] shape to provide
superior energy transfer. Fin thickness shall be [0.0075”] [0.0060”] and available in a uniform
density between 6 to 14 fins per inch.
2.9.2.3 Tubing and return bends shall be constructed from UNS 12200 seamless copper and
annealed with a maximum grain size 0.040 mm. Tubes shall be mechanically expanded into fins to
form an interference fit.
2.9.2.4 Headers shall be constructed of seamless UNS C12200. Header end caps shall be dieformed and installed on the inside diameter of header such that the landed surface is three times
the header wall thickness.
2.9.2.5 Coil casing and endplate shall be fabricated from [galvanized steel] [aluminum] [304
stainless steel] [316 stainless steel]. All tube sheet cutouts shall be oversized to allow for free
thermal expansion. Coils 50 inches or greater shall be fabricated with intermediate tubing supports
constructed of same material and gauge of end plates.
2.9.2.6 All coils shall be brazed with a filler material that is a minimum 5% silver in joining header
and core tubes.
2.9.2.7 [Coils shall be provided with a corrosion resistant [e-coat] [electrofin] [epoxy] [Blygold]
coating.]
2.9.3 [Evaporator Coil] (see CSI Division 23 82 16.13)
2.9.3.1 Evaporator coils shall be safety listed to withstand pressures of 600 psig or more. All coils
shall be manufacturer tested to at least 550 psig while submerged in water. If refrigerant piping is
split, coils shall be shipped with a nitrogen charge to prevent moisture ingress.
2.9.3.2 Fins shall be a plate-fin design using [aluminum] [copper] that cover entire tube surface
with self-spacing collars. Fin surface shall be a formed [flat] [waffle] [sine-wave] to provide superior
energy transfer. Fin thickness shall be [0.0075”] [0.0060”] and available in a uniform density
between 6 to 14 fins per inch.
2.9.3.3 Tubing and return bends shall be constructed from UNS 12200 seamless copper and
annealed with a maximum grain size 0.040 mm. Tubes shall be mechanically expanded into fins to
form an interference fit. Micro channel tubing is not acceptable. Tubing shall be internally enhanced
rifled-type.
2.9.3.4 Headers shall be constructed of seamless UNS 12200 copper. Header end caps shall be
die-formed and installed on the inside diameter of header such that the landed surface is three
times the header wall thickness.
2.9.3.5 Coil casing and endplate shall be fabricated from [galvanized steel] [aluminum] [304
stainless steel] [316 stainless steel]. All tube sheet cutouts shall be oversized to allow for free
thermal expansion. Coils 50 inches or greater shall be fabricated with intermediate tubing supports
constructed of same material and gauge of end plates.
2.9.3.6 All coils shall be brazed with a filler material that is a minimum 5% silver in joining header
and core tubes.
2.9.3.7 [Coils shall be provided with a corrosion resistant [e-coat] [electrofin] [epoxy] [Blygold]
coating.]
2.9.4 [Hot Gas Reheat Coil]
2.9.4.1 Hot gas reheat coils shall be safety listed to withstand pressures of 600 psig or more. All
coils shall be manufacturer tested to at least 550 psi while submerged in water. If refrigerant piping
is split, coils shall be shipped with a nitrogen charge to prevent moisture ingress.
2.9.4.2 Fins shall be a plate-fin design using [aluminum] [copper] that cover entire tube surface
with self-spacing collars. Fin surface shall be a formed [flat] [waffle] [sine-wave] to provide superior
energy transfer. Fin thickness shall be [0.0075”] [0.0060”] and available in a uniform density
between 6 to 14 fins per inch.
2.9.4.3 Tubing and return bends shall be constructed from UNS 12200 seamless copper and
annealed with a maximum grain size 0.040 mm. Tubes shall be mechanically expanded into fins to
form an interference fit. Micro channel tubing is not acceptable. Tubing shall be internally enhanced
rifled-type.
2.9.4.4 Headers shall be constructed of seamless UNS 2200 copper. Header end caps shall be dieformed and installed on the inside diameter of header such that the landed surface is three times
the header wall thickness.
2.9.4.5 Coil casing and endplate shall be fabricated from [galvanized steel] [aluminum] [304
stainless steel] [316 stainless steel]. All tube sheet cutouts shall be oversized to allow for free
thermal expansion. Coils 50 inches or greater shall be fabricated with intermediate tubing supports
constructed of same material and gauge of end plates.
2.9.4.6 All coils shall be brazed with a filler material that is a minimum 5% silver in joining header
and core tubes.
2.9.4.7 [Coils shall be provided with a corrosion resistant [e-coat] [electrofin] [epoxy] [Blygold]
coating.]
2.9.5 [Condenser Coil]
2.9.5.1 Condenser coils shall be safety certified to withstand 750 psig. Coils shall be manufacturertested to at least 550 psig using dry nitrogen, submerged under water.
2.9.5.2 If refrigerant piping is split for shipment, coils shall be shipped with a nitrogen charge to
prevent moisture ingress.
2.9.5.3 Fins shall be of plate-fin design using either aluminum or copper that cover the entire tube
surface with self-spacing collars. Fin surfaces shall be a formed [flat] [waffle] [sine-wave] design to
provide superior energy transfer. Fin thickness shall be [0.0075”] [0.0060”] and shall be installed in
a uniform density between 6 and 14 fins per inch.
2.9.5.4 Tubes and return bends shall be constructed from seamless UNS C12200 copper,
conforming to ASTM B224 and ASTM E527. Properties shall be O50 Light annealed, with a
maximum grain size of 0.040 mm. Tubes are to be mechanically expanded into the fins for
maximum heat transfer. Tubing is to be internally enhanced rifled-type. Micro channel tubing is not
acceptable.
2.9.5.5 Headers shall be constructed of seamless UNS C12200 copper material sized to match
specified connection size. Headers are to have finished integral spin-closed ends designed to
withstand test pressure.
2.9.5.6 Coil casing material shall be [G90 galvanized steel, 16 gauge minimum thickness]
[aluminum] [304 stainless steel] [316 stainless steel]. Intermediate tube supports shall be provided
on all coils having 50” or longer fin length.
2.9.5.7 All coils shall be brazed with a minimum 5% silver content filler material to ensure joint
integrity.
2.9.5.8 [Coils shall be provided with a corrosion resistant [e-coat] [electrofin] [epoxy] [Blygold]
coating.]
2.10 CONDENSING SECTION:
2.10.1 Outdoor coils shall be plate fin type, constructed out of formed aluminum. Fins shall extend the
full length of the piping and shall be mechanically bonded. Each coil shall be tested from manufacturer
with high pressure air while submerged in water. Coil tubes shall be standard construction; microchannel shall not be accepted.
2.10.2 All condensing section coils that are split for shipment are to be charged with pressurized
nitrogen.
2.10.3 Condensing fan shall be an axial aluminum construction, 7 sickle blade design with fluted
edges, and a fan manufacturer produced high efficiency nozzle housing. All fans shall include a
protective cage to protect against accidental contact and damage.
2.10.4 Condensing fans shall be directly driven with an electrically commutated motor without need of
a variable frequency drive. Fans shall be proportionally controlled to maintain head pressure of
refrigerant circuit.
2.10.5 Unit shall employ scroll compressors. (see CSI Division 23 61 19) Compressors shall be
[digitally controlled] [VFD driven] to provide efficient turn-down. Refrigeration system shall incorporate
the following safeties:
2.10.5.1 High pressure
2.10.5.2 Low pressure
2.10.5.3 Minimum off time
2.10.5.4 Maximum on time
2.10.6 Each refrigeration circuit shall contain:
2.10.6.1 Line vibration absorber
2.10.6.2 Site glass
2.10.6.3 Thermal expansion valve [electronic expansion valve]
2.10.6.3 Filter drier
2.10.6.4 Head pressure control
2.10.6.6 [Hot gas bypass]
2.10.6.7 [Hot gas reheat valve]
2.10.7 Each circuit shall be dehydrated and factory charged with R-410A refrigerant and oil.
2.10.8 Each compressor and condenser fan motor shall be furnished with contactors and inherent
thermal overload protection.
2.10.9 All openings in condensing section shall be covered with [bird screen] [hail guard] [cottonwood
screen]
2.11 [INDIRECT-FIRED NATURAL GAS BURNER] (see CSI Division 23 55 13.16)
2.11.1 Provide furnace module listed by Intertek Testing Services (ITS / ETL), a Nationally Recognized
Testing Laboratory (NRTL) as a recognized component, to the current edition of ANSI Z83.8 / CSA 2.6.
Duct furnace module shall provide a minimum combustion efficiency of 80%.
2.11.2 The duct furnace modules shall be listed for either outdoor installation (or) for indoor installation
in accordance with Category I and Category III venting systems without need for additional power
venting.
2.11.3 Gas-fired duct furnace(s) provided shall have a tubular heat exchanger constructed of [409
stainless steel] [304 stainless steel]. Heat exchanger tubes shall be mechanically secured to vestibule
panels and design shall be suitable to withstand 3.0” w.c. total external static pressure.
2.11.4 Duct furnace modules shall be listed for application downstream of refrigeration and cooling
systems and shall provide means for removal of condensate that occurs in the heat exchanger tubes
during cooling operation. Heat exchanger tubes shall have integral formed dimpled restrictors to provide
for an unobstructed drainage path and tubes shall be formed to provide a positive pitch to promote
condensate drainage. Drainage shall be configured so that burners are not exposed to condensate.
2.11.5 Duct furnace module shall employ:
2.11.5.1 In-shot gas burners, with integral carryovers, [operating at 1:1 turndown] [capable of
operation at [2:1] [5:1] [10:1] turndown with modulating controls.]
2.11.5.2 An induced-draft combustion air blower to provide for positive venting of flue gases
2.11.5.3 Combustion air pressure switch to prove air supply for combustion
2.11.5.4 Direct spark ignition of the gas burners with remote flame sensor to prove carryover
across all burners
2.11.5.6 Listed combination gas valve incorporating redundant (two) electric safety shut-off valves,
manual shut-off , and gas regulator which regulates gas pressure to burner supply manifold.
2.11.5.7 An automatic reset type high limit switch to limit maximum outlet air temp to less than 250
°F
2.11.5.8 Manual reset flame rollout switch(es)
2.11.5.9 A Class II step down transformer to provide 24 VAC control voltage at selected supply
voltage
2.11.5.10 Duct furnace shall incorporate a direct spark ignition control module that is design
certified by a NRTL to ANSI Z21.20 and CAN/CSA-C22.2. The control shall provide 100% safety
shut-off.
2.11.5.11 A minimum 15 second pre-purge to provide a minimum of four (4) air changes
2.11.5.12 A maximum 0.8 second flame failure response time
2.11.5.13 Two additional ignition retrials preceded by an inter-purge period
2.11.5.14 A minimum 30 second post-purge
2.11.5.15 An automatic reset after one hour should a lockout occur
2.11.5.16 An LED indicator light to provide a flash code to identify operating condition of control
2.11.5.17 An alarm-capable contact
2.11.5.18 A 1/8” NPT tapped test gauge connection in the gas manifold for measuring gas pressure
2.11.5.19 A union fitting downstream of gas control to facilitate installation and service
2.11.5.20 Provision for attachment of a vent system to exhaust flue gases to outdoors.
2.11.5.21 All electrical components shall be listed or recognized by a NRTL (ETL, UL, CSA, etc.).
2.12 [DIRECT-FIRED NATURAL GAS BURNER] (see CSI Division 23 55 13.16)
2.12.1 Provide direct gas-fired heat module manufactured as a recognized component to the current
edition of ANSI Z83.4 / CSA 3.7 Standard. The final determination of the safety and suitability of this
product for the specific application shall be the responsibility of the manufacturer.
2.12.2 The heat modules may be used for indoor installation in accordance with the National Fuel Gas
Code ANSI Z223.1 (NFPA 54) in the United States and Can/CGA-B149 Installation Code in Canada
and all applicable local codes and ordinances.
2.12.3 Heat module shall provide 100% efficiency of combustion and a minimum thermal efficiency of
92%.
2.12.4 Direct gas-fired heat modules shall be used for pull-through applications.
2.12.5 Direct gas-fired heat module(s) provided shall have a stainless-steel burner with aluminum
burner head casting. Burner assembly shall be mechanically secured to vestibule panels and design
shall be suitable to operate as low as 0.35” to 1.2” w.c. differential pressure range or air velocity as low
as 1500 to 3500 fpm.
2.12.6 Profile plate openings are sized according to specific application requirements.
2.12.7 Additionally, heat module shall employ:
2.12.7.1 Gas burners, with integral carryovers, capable of operation at 30:1 turndown with
modulating controls.
2.12.7.2 A profile plate opening sized according to specific application requirements.
2.12.7.3 Burner circulating air pressure switches to prove air supply for combustion and operation.
2.12.7.4 Flame safeguard of the gas burners with integral flame sensing to prove carryover across
burner assembly.
2.12.7.5 Listed gas valve(s) incorporating electric safety shut-off valves, and/or manual shut-off,
and/or proof of closure, and/or visual indication, and/or gas regulator.
2.12.7.6 An automatic reset type high limit switch set to 185°F.
2.12.7.7 Class II step down transformer(s) to provide 24 VAC control voltage at selected supply
voltage.
2.12.7.8 A 1/8” NPT tapped test gauge connection in the gas train for measuring gas manifold
pressure.
2.12.7.9 A 1/8” NPT tapped test gauge connection in the gas train for measuring inlet supply gas
pressure.
2.12.7.10 A union fitting upstream and downstream of gas control to facilitate installation and
service.
2.12.7.11 Provision for attachment of a vent system to exhaust gas from the gas vent valve
according to national or local codes.
2.12.7.12 All electrical components shall be listed or recognized by a NRTL (ETL, UL, CSA, etc.).
2.12.7.13 Heat modules and burners provided are for use on natural or propane gases as specified
at the time of order.
2.12.7.14 Manifold and gas train built to ANSI, FM, UL, IRI/GAP, or local codes as specified at the
time of order.
2.13 DAMPERS
2.13.1 Control dampers: Dampers shall be [opposed] [ parallel]-blade, with a leakage Class 1A of
which the leakage rate shall not exceed 3 cfm/sq. ft. (15 L/s m2) at 1 in. w.g. (249.09 Pa) pressure
differential when tested in accordance to AMCA 500. Dampers shall be provided with [galvanized]
[aluminum] [stainless steel] [airfoil] [formed] [single] [multi] piece blades with a [metal compressible] [
extruded silicone] type jamb seal with TPE blade seals.
2.13.2 Control dampers meeting the following specifications shall be furnished and installed where
shown on plans and/or as described in schedules.
2.13.3 Damper blades shall be [galvanized steel] [aluminum] type. Linkage shall be blade-to-blade
concealed in jamb (out of the airstream) to protect linkage and reduce pressure drop and noise.
2.13.4 Damper frame shall be [galvanized steel] [aluminum] Bearings shall be corrosion resistant,
permanently lubricated, synthetic sleeve type rotating in extruded holes in the damper frame for
maximum service. Axles shall be square and positively locked into the damper blade.
2.13.5 The damper manufacturer's submittal data shall certify all air leakage and air performance
pressure drop data is licensed in accordance with the AMCA Certified. Damper air performance data
shall be developed in accordance with the latest edition of AMCA Standard 500-D.
2.14 ACTUATORS
2.14.1 Actuators for [outdoor] [return] [recirculation] [exhaust] [bypass] shall be controlled with a [spring
return] [non-spring return] [modulating] [2 position] actuator.
2.14.2 Actuators shall be direct coupled which don’t require a crank arm. Actuators shall be designed
so that they may be used for either clockwise or counter clockwise fail-safe operation. Actuators shall
be driven by a brushless direct current motor which shall keep run time consistent, and independent of
torque.
2.15 LIGHTS
2.15.1 LED Lights: Factory shall provide IP65, low profile LED lighting strips in locations noted in
submittal drawings. Low voltage wiring shall be completed by factory and wired to switch easily
accessed from exterior of unit.
2.15.2 [Marine Light: Factory shall provide vapor proof pendant, marine type light fixture with clear
globe, and metal guard. Factory shall wire each section to a separate 120 volt switch easily accessed
from exterior of unit.]
2.15.3 UV LIGHTS
2.15.3.1 UV Lights: A UV lighting system shall be factory installed [before] [after] [the cooling coil to
prevent build-up on coil] [in supply plenum]. UV bulb shall not be covered on any side and shall be
coated to contain glass and chemicals should lamp break.
2.15.3.2 [Each bank of UV lights shall have its own radiometric monitor that tracks lamp run-time
and lamp performance. Monitor shall be interfaceable with building management system. ]
2.16 BIPOLAR IONIZATION:
2.16.1 Bipolar Ionization: A needle point bipolar ionization system shall be factory installed. Ionization
system shall be corrosive resistant and able to interface with building management system. Ionization
should be mounted [return] [downstream of coil] [leaving unit] [supply plenum] and shall not introduce
ozone or byproducts from the system.
2.17 HUMIDIFIER:
2.17.1 Humidifier: A tube-in-tube construction humidifier shall be provided internal to unit. Humidifier
shall be the final component in supply air stream to prevent damage to other components.
2.17.2 Humidifier shall be designed for short absorption applications and to be directly injected into air
stream. Unit shall comply with ARI 640, “Standard for Commercial and Industrial Humidifiers”.
2.17.3 Humidifier shall have a steam dispersion panel consisting of a (one) horizontal stainless steel
header supplying steam to a bank of closely spaced 3” (7.6 cm) OR 6” (15.2 cm) OR 9” (22.9 cm) OR
12” (30.5 cm) vertical tubes 3” (7.6 cm) OR 6” (15.2 cm) for mini units), as necessary to meet
absorption distance requirements, and to reduce condensation losses.
2.17.4 Humidifier shall have a single horizontal stainless steel header to provide steam to vertical
distributor tubes and to reduce condensation losses. Dual header systems are not acceptable.
2.17.5 Header design is primarily round tube to minimize pressure drop. Square headers are not
acceptable. (Full-size units only).
2.17.6 Steam inlet and condensate return are to be located on the same side and at the bottom of the
header to allow single point entry and floor mounting.
2.17.7 Headers are to be 304 stainless steel construction.
2.17.8 Vertical stainless steel distribution tubes shall be used to promote condensate evacuation.
Horizontal distributor tubes are not accepted.
2.17.9 All tubes shall be [409] [304] stainless steel construction.
2.17.10 Stainless steel nozzle inserts shall be used to ensure condensate free steam is discharged
from the center of the distribution tubes. Systems without nozzle inserts, or other than stainless steel,
are not acceptable.
2.17.11 Stainless steel nozzle inserts shall have metered orifices, sized to provide even distribution of
the discharged steam, spaced for optimum steam absorption.
2.18 UNIT HOODS
2.18.1 Weather hoods shall be same material and thickness as unit exterior skin with ¼” square
galvanized mesh bird screen. Outdoor intake hoods and louvers shall be designed in accordance of
ASHRAE 62.1.5.5.2
2.18.2 Limit water penetration through the intake to 0.07 oz/ft2-h (21.5 g/m2-h) of inlet area when
tested using the rain test apparatus described in Section 58 of UL 1995.
2.18.3 Use rain hoods sized for no more than 500 fpm (2.5 m/s) face velocity with a downward-facing
intake such that all intake air passes upward through a horizontal plane that intersects the solid
surfaces of the hood before entering the system.
2.18.4 Manage the water that penetrates the intake opening by providing a drainage area and/or
moisture removal devices.
2.19 UNIT LOUVERS
2.19.1 Outdoor air intakes that are part of the mechanical ventilation system shall be designed to
manage rain entrainment in accordance with ASHRAE 62.1.5.5.2
2.19.2 Select louvers that limit water penetration to a maximum of 0.01 oz/ft2 (3 g/m2) of louver free
area at the maximum intake velocity. This water penetration rate shall be determined for a minimum
15-minute test duration when subjected to a water flow rate of 0.25 gal/min (16 mL/s) as described
under the Water Penetration Test in AMCA 500-L or equivalent. Manage the water that penetrates the
louver by providing a drainage area and/or moisture removal devices.
2.19.3 Select louvers that restrict wind-driven rain penetration to less than 2.36 oz/ft2-h (721 g/m2-h)
when subjected to a simulated rainfall of 3 in. (75 mm) per hour and a 29 mph (13 m/s) wind velocity at
the design outdoor air intake rate with the air velocity calculated based on the louver face area.
2.20 ELECTRICAL
2.20.1 Unit wiring shall comply with UL standards. All electrical components shall be listed or
recognized by a NRTL (ETL, UL, CSA, etc.). All wiring and electrical components provided with the unit
shall be labeled according to the electrical diagram provided for easy identification. The unit shall be
provided with a factory wired weatherproof control panel. Unit shall have a [single] [multi] point power
terminal block for main power connection. A terminal strip shall be provided for low voltage control
wiring. Supply fan motors shall have contactors and external overload protection. Space shall be
provided for field wiring entrance.
2.20.2 A [single] [multiple] [non–fused] [fused] disconnect switch shall be provided for disconnecting
electrical power at the unit.
2.20.3 Unit shall be provided with factory mounted
2.20.3.1 [Branch short circuit protection]
2.20.3.2 [115 -volt control circuit transformer and fuse] [115-volt convenience outlet]
2.20.3.3 [System switches]
2.20.3.4 [Remote panel]
2.20.3.5 [Unit split electrical connections]
2.20.3.6 [Phase protection relay]
2.20.3.7 [Insert other electrical options (Verify with XeteX)]
2.21 CONTROLS
2.21.1 Unit control equipment and sequence of operation shall be provided as specified in Section
[Insert section location; controls schematic; schedule]. Controls shall be provided by [unit manufacturer]
[controls contractor]
2.21.2 [Provide a complete integrated microprocessor based Direct Digital Control (DDC) to all unit
functions including temperature control, monitoring, unit safety protections, and diagnostics. The
controls system shall consist of all required items including but not limited to [temperature sensors]
[pressure sensors] [humidity sensors] [keypad/display user interface]. In addition to the DDC controller,
a remote user terminal shall be provided that mirrors the functions and displays of the DDC.]
2.21.3 Controls interface shall connect to [terminal strip for BAS to interface with unit components] [unit
control board with [BACnet IP] [BACnet MSTP] [LonTalk] [ModBus] connectivity].
PART 3 - EXECUTION
3.1 INSTALLATION
3.1.1 Install equipment per industry standard, applicable codes, and manufacturer’s instructions.
3.1.2 Units shall not be used for temporary heating, cooling, or ventilation prior to complete inspection
and startup performed per this specification without manufacturer’s authorization.
3.1.3 Equipment shall be mounted on [curb] [dunnage] [concrete pad] in accordance with local codes.
Mounting unit on anything but approved curb, dunnage, or pad will not be allowed. If unit is mounted on
a curb, the curb is to be leveled on the underside, providing a level bearing surface with uniform support
for the air handler.
3.1.4 Unit shall be installed plumb and level. Connect piping and ductwork according to the
manufacturer’s instructions.
3.1.5 Installation of units shall be done with manufacturers recommended clearances for access and
coil pull.
3.1.6 One complete set of filters shall be included with unit for testing, balancing, and commissioning.
Provide additional [no] [1] [2] [3] [4] additional filter sets at time of transfer to owner.
3.1.7 Provide and install seismic restraints and anchors per applicable local building codes.
3.1.8 All piping and electrical connections shall be completed per manufacturer’s instructions. Insulate
all plumbing associated with the drain pan drains and connections. Insulate any piping that may freeze
or be affected by environment.
3.2 DELIVERY, STORAGE, AND HANDLING:
3.2.1 FIELD QUALITY CONTROL
3.2.1.1 Unit(s) shall be stored per manufacturer’s written recommendations.
3.2.1.2 Unit(s) shall be stored indoors in a warm, clean, dry location where unit(s) will be protected
from the weather, construction traffic, dirt, dust, water, and moisture. If units(s) is to be stored for
more than 1 month, manufacturer’s instructions for unit storage shall be followed.
3.2.1.3 Rig and lift units in accordance to manufacturer’s instructions.
3.2.1.4 Engage a factory authorized test to verify all connections, controls, and unit performance.
3.3 FIELD INSPECTION
3.3.1 A manufacturer authorized technician shall perform an inspection of unit and installation location
prior to start-up. Authorized technician shall inspect, record and report the following as a minimum:
3.3.1.1 Damage of any kind.
3.3.1.2 Level and plumb of installation location.
3.3.1.3 Proper reassembly and sealing of unit segments at shipping splits.
3.3.1.4 Tight seal around perimeter of unit at roof curb.
3.3.1.5 Installation of shipped-loose parts, which may include filters, air hoods, bird screening, and
mist eliminators.
3.3.1.6 Completion of electrical, ductwork and piping.
3.3.1.7 Tight seals around wiring, conduit and piping penetrations through unit casing.
3.3.1.8 Supply of electricity from the building’s permanent source.
3.3.1.9 Integrity of condensate trap for positive and negative pressure operation.
3.3.1.10 Condensate traps fabricated in compliance with instructions in the unit IOM and charged
with water.
3.3.1.11 Proper removal of shipping bolts, restraints, wrapping.
3.3.1.12 Verify full range of motion in damper blades and linkages.
3.3.1.13 Complete installation of control system including end devices, field installed devices, and
wiring.
3.3.1.14 Cleanliness of unit(s) interior and connecting ductwork.
3.3.1.15 Proper service and access clearances.
3.3.1.16 Calibration and testing of filter gauges and switches.
3.4 CLEANING
3.4.1 Clean unit interior prior to operation, including the removal of all tools, debris, dust and dirt.
3.5 DOCUMENTATION
3.5.1 INSTALLATION, OPERATION AND MAINTENANCE MANUAL
Manufacturer shall provide a single manual containing detailed information regarding the
installation, operation, maintenance, and safety of the unit. The installation portion of the manual
shall include detailed information on factory-recommended locations of electrical and piping
penetrations and provide factory-recommended techniques for making the penetrations. It shall
provide maintenance information on [filter replacement] [motor and drive maintenance] [damper
and actuator maintenance ] [cleaning procedures] [control sequence] and other required
maintenance for all unit components. It shall provide recommended maintenance schedules to
include Start-Up Maintenance, Seasonal Maintenance and Periodic Maintenance. Manual shall be
shipped with the unit and available electronically upon request.
3.5.2 Provide list of all spare parts upon request.
XeteX Guide Spec Rev_00
Copyright Mar, 2022