CLEANROOM RECIRCULATION AIR HANDLING UNIT SPECIFICATION
1. Cleanroom Recirculation Air Handling Units Testing and Standards
1.1. Unit shall be completely factory assembled and tested prior to shipment and shall be listed per
UL 1995, as a complete assembly and shall be labeled as such. Fans shall be tested and rated in
accordance with AMCA Standard 210 for performance and in accordance with ANSI standards
of testing for sound power levels using the sound intensity method as referenced in AMCA
standard 320 for sound.. If the manufacturer cannot provide an ETL/UL sticker on the air
handler, it will be the sole responsibility of the contractor to arrange for local ETL or UL
approval and labeling.
1.2. The Unit Electrical Panel(s) shall be built in strict accordance to NEC Standards and shall bear an
appropriate label certifying compliance with UL Standard 508A.
1.3. The air handling equipment manufacturer shall provide single source responsibility for all
components for the unit whether specifically manufactured by the unit manufacturer or
obtained
outside and installed in the equipment with the exception of consumable items such as filters,
fan belts, etc., or as specifically warranted by the product manufacturer such as motors, VFD’s,
etc.
1.4. The attached schedules, tables and specifications are to be used as the selection criteria for the
air handling equipment to include Air Flow Rates, External Static Pressures and Water Flow
Rates. The following are to be equaled or bettered: Coil Face velocities and Filter Face
Velocities. The following are to be met within 5% of specified values: internal air pressure drops
using an AMCA leak testing machine with calibrated orifices, water pressure drops.
1.5. Additional Testing and Quality Assurance as explained in individual component / item sections
in the following paragraphs of this specification.
2. Submittals:
2.1. Submit shop drawings with product data.
2.2. Shop drawings shall indicate assembly weights, unit dimensions, required clearances,
construction details, and field connection details.
2.3. Product data shall indicate dimensions, weights, capacities, ratings, fan performance to include
fan curves, motor electrical characteristics to include motor technical data sheets, coil
capacities to include performance printouts with pressure drops (water & air), vibration
isolation, filter data sheets to include pressure drops, gauges and finishes.
2.4. Clearly identify any variations from contract documents.
2.5. Provide space on cover document for contractor and architect/engineer review stamps.
2.6. Revise & resubmit submittals as required.
3. Operation and Maintenance Data:
3.1. Submit installation, start-up and Operation & Maintenance Data.
3.2. Include instructions for rigging, lifting, bearing lubrication, filter replacement, motor and drive
replacement, and wiring diagram.
© CES Group, LLC CLEANPAK | 19855 SW 124th Ave, Tualatin, OR 97062 | 503.639.0113 | www.huntair.com
Last Rev: 2/12/2016 Page 1 of 10
3.3. Include a recommended spare parts list customized to each unit complete with appropriate tag
#, serial and / or part numbers along with a description to clearly identify the items.
4. Cabinet:
4.1. Casing Construction: Walls and roof to be (2”) (4”) (6”) (other) “Single Wall” or “Double Wall”
construction as indicated in the specification for each section of the unit. Cabinet is with a
minimum 16-gauge (or 14-gauge) A60 galvanized (G-90) (Alum) (SS) solid outer panel and a
minimum 20-gauge G90 galvanized, inner liner for double walls (solid, perforated…). Panels to
be of standing seam construction with seams turned inward to provide a smooth flush exterior.
Panels to be screwed (bolted) together on maximum 8” centers with minimum 5/16” zinc
plated screws (bolts) sealed with a continuous bead of silicone caulking applied between the
matching panel seams prior to assembly (sandwiched and sealed by the compression of the
panels), and with a final bead following assembly on both the exterior and interior panel seams
to produce an air tight unit. Wall to base skin and wall to roof panel seams shall be sealed with
1/2” x 1/8” Poron-Rubber strips and all exterior seams shall be continuously caulked to assure
leak-proof integrity of the unit housing. AHU unit housing shall be constructed to prevent
conditioned air bypass or mitigation through unit walls, roof and floor around any interior
partition or component blank-off walls such as for filters, coils or fan bulkheads. At the
discretion of the design engineer, the manufacturer may be required to perform casing leak
testing for purposes of demonstrating that the unit casing leakage rate at 1.5 times the design
maximum fan operating static pressure is less than .5% of design airflow. Such testing will be
performed at the manufacturer’s facility. At the sole discretion of the design engineer, such
testing shall be witnessed by an owner’s representative. A certified test report of such testing
shall be included in the O&M Manuals provided at the time of shipment of the equipment.
4.2. Insulation: Panels to be insulated with 2” - 3-pound double density pre-molded rigid board fireresistant with (matte face) (scrim-Kraft - PSK faced insulation. (Optional 1.5, 4.5, 6 pound
density or other). Insulation to meet NFPA 90A, NFPA 90B and ASTM E 84 requirements for
Flame Spread of 25 or less and Smoke Development of 50 or less. Insulation shall have a
thermal conductivity K factor of .23 Btu/hr/Sq. ft/degree F @ 75 F mean and provide the
following sound attenuation characteristics (per ASTM C 423 - Type “A” Mounting):
Octave bands
125 250 500 1k
2k
4k
8k
Absorption Coefficient .17 .80
1.16 1.15 1.11 1.10 1.05 (for 2” – 3#)
All cut edges of the board insulation shall be completely enclosed by the unit panels.
A finish bead of caulking will be applied over all foil to panel seams and/or inner liners
to main panel seams to completely encapsulate the insulation.
4.3. Interior liners: to be minimum 20-gauge G90 (304 SS or Alum) powder coated solid (perforated)
metal throughout the unit for the walls and roof except in the cooling coil section, humidifier
section and its immediate downstream plenum which will have solid 304 SS inner liners. A finish
bead of caulking will be applied between the liner and the interior panel seams to completely
seal the panel.
4.4. Roof panels: on units shall be flat with smooth exteriors the same as the side panels. All doors
and louvers shall have a formed rain shield extending a minimum of 1” from the wall to direct
water away from the door and louver openings.
4.5. Stiffeners of angle steel shall be supplied as required to maintain a casing deflection criteria of
1/100 at 1.5 times the working pressure.
5. Access Doors:
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Last Rev: 2/12/2016 Page 2 of 10
5.1. Access doors shall be (2.6”) double wall (thermal break) construction with (G-90 galvanized)
(304 Stainless Steel) (Aluminum) exterior panels and (G-90 galvanized) (Aluminum) (304
Stainless Steel) interior panel. Door jam & frame shall be constructed of extruded aluminum
with continuously welded corners for rigidity. Door panels shall be insulated with (2.6”)
expandable urethane foam insulation completely encapsulated and sealed between the door
panels and frame. Provide doors located and sized to allow for routine maintenance including
motor replacement and filter replacement, electrical components and any other sections or
components requiring access or maintenance.
5.2. Doors shall be provided with a minimum (2) dual acting heavy duty key locking composite
latches through 48” high, (3) latches through 72” high. Latches shall be operable from both the
interior and exterior of the unit. Door latches on doors into fan sections shall be provided with
a hasp or other mechanism to facilitate locking of the doors. Door hinge shall be heavy duty
Stainless Steel. Door shall be sealed with continuous hollow closed cell foam gasket.
5.3. Doors to be provided with double high performance closed cell replaceable neoprene bulb type
gasket seals around the entire perimeter of the door / frame.
5.4. Doors shall open against static pressure unless obstructed by internal components. If
obstructed by internal components on the positive sections requiring access, the doors shall
open with pressure and shall be provided with a safety restraining mechanism. Doors used to
access rotating equipment shall be provided with an OSHA approved safety latching mechanism
requiring a tool to open and shall also have a highly visible, permanently fixed, caution sign on
the exterior of the door. Doors with access to moving parts must also have locking hardware
and meet current UL mechanical protection guidelines. Standard door size shall be 24” wide by
60” high unless restricted by height or section width.
5.5. Doors shall be provided with (double) (thermal pane wire) glass viewing windows as called out
for on the unit drawings in the specifications. Minimum window size to be 9” x 9” with 12” x
12” provided door size permitting.
6. Bases:
6.1. Unit bases shall be constructed from structural steel channel iron or tubing around the entire
perimeter of the unit and provided with intermediate structural tubing, channel and angle iron
as required to support all internal components. All tubing, channel and angle joints shall be
solid welded. Bolted or formed channel bases are not acceptable.
6.2. Base shall be provided with removable lifting lugs minimum (4) per section, properly located to
assure uniform loading. Maximum spacing between lifting lugs shall be 120”.
6.3. Drain pans shall be 304 (3/16) Stainless Steel double-walled construction with solid welded
seams for complete water capture and containment. Pans under cooling coils shall extend a
minimum 12” passed the leaving face of the coil in direction of airflow. Drain Pans shall be fully
recessed in the unit floor and all headers and return bends shall be located over the drain pan
for collection of all condensate forming on headers and return bends. All coils shall be easily
removable without cutting or removing any portion of the drain pan. Pans shall be insulated
between the liner and the main pan. Pans shall be IAQ Double Sloping to a single drain. Drain
connection shall be a minimum 1-1/4” diameter MIPS thread extending out through the
channel base the same side as the coil connections unless other wised indicated on the
drawings. Pans shall be provided for cooling coils, humidifiers, outside air intakes and under
other components as required. Mastic coated drain pans are not acceptable as they are “nonCleanable”.
© CES Group, LLC CLEANPAK | 19855 SW 124th Ave, Tualatin, OR 97062 | 503.639.0113 | www.huntair.com
Last Rev: 2/12/2016 Page 3 of 10
6.4. All large openings (greater than one square foot) in the floor, including dampers openings, shall
be covered with a removable powder coated heavy gauge steel grating bolted in place suitable
for walking on which will prevent any personnel and large objects from falling through into the
space below. Grating shall be capable of supporting minimum 300 pounds.
6.5. Provide a perimeter collar around the entire unit and around each floor opening to insure unit
is watertight. The entire base shall act as a secondary drain pan to hold up to 1” of water.
6.6. All OSA (Outside Supply Air) openings shall have a recessed drain pan.
7. Coating:
7.1. All wall, roof, interior divider walls, racks, blank-offs and the Base Structure shall be coated with
a Dry Powder - Baked Polyester coating. Each cabinet panel, panel liner and interior partition
component is to be individually coated & baked following shearing, notching, punching, &
forming to provide 100% powder coverage over the entire finished piece to include the interior,
exterior and all metal edges.
The coating process is completed prior to assembly of the unit too unsure all joined surfaces
(panel to panel joints), are covered. Spray or brush applied coatings on the exterior of the
cabinet only are not acceptable. Powder Paint to have passed Salt Spray Resistance Test ASTM
B 117-90 Minimum 1500 Hours, Impact Test ASTM D 2794-90 up to 160 lbs and Humidity
Resistance Test ASTM D 2247-87 Minimum 1500-hour test w/ maximum blister 1/16 in/1 mm.
7.2. Powder Coated unit to be wet white (or Architect / Owner specified).
8. Fan Wall Technology (FWT)
8.1. The Fan Wall System, as manufactured by Huntair Inc., shall consist of multiple, direct driven,
arrangement 4 plenum fans constructed per AMCA requirements for the duty specified, (Class
I, II, or III). All fans shall be selected to deliver the specified airflow quantity at the specified
operating Total Static Pressure and specified fan/motor speed. The Fan Wall Array shall be
selected to operate at a system Total Static Pressure that does not exceed 90% of the specified
fan’s peak static pressure producing capability at the specified fan/motor speed. Each
fan/motor (cube) (cartridge) shall include an 11-gauge, A60 Galvanized steel intake wall, 14
gauge spun steel fan inlet funnel, and an (11 gauge G90 Galvanized steel motor support plate
and structure) (fully welded structural steel angle iron frame designed to support a pedestal
mounted arrangement 4 direct drive fan/motor assembly). The fan intake wall, inlet funnel,
and motor support structure shall be powder coated for superior corrosion resistance. All
motors shall be standard pedestal mounted type, (ODP) (TEFC) (TENV), T-frame motors
selected at the specified operating voltage, RPM, and efficiency as specified or as scheduled
elsewhere. All motors shall include isolated bearings or shaft grounding. Each fan/motor
cartridge shall be dynamically balanced to meet AMCA standard 204-96, better than category
BV-5, to meet or exceed Grade 0.55 residual unbalance.
8.1.1. The FWT array shall be provided with coplanar acoustical silencers that reduces the bare
fan discharge sound power levels by a minimum of 15 db re 10^-12 watts throughout
the eight octave bands with center frequencies of 125, 250, 500, 1000, 2000, 4000, and
8000 HZ when compared to the same unit without the silencers. The silencers shall not
increase the fan total static pressure, nor shall it increase the airway tunnel length of
the Air Handling Unit when compared to the same FWT unit without the silencer array.
8.1.2. Alternate manufacturers must submit acoustical data for review and approval prior to
the bid indicating that the proposed alternate equipment can meet all specified
© CES Group, LLC CLEANPAK | 19855 SW 124th Ave, Tualatin, OR 97062 | 503.639.0113 | www.huntair.com
Last Rev: 2/12/2016 Page 4 of 10
performance requirements without impacting the equipment performance or design
features including duct connection location, unit weights, acoustical performance, or
specified total fan HP for each FWT array. Proposals submitted which indicate a higher
connected fan HP than specified or scheduled will not be accepted.
8.2. The fan array shall consist of multiple fan and motor ”cubes”, spaced in the air way tunnel
cross section to provide a uniform air flow and velocity profile across the entire air way tunnel
cross section and components contained therein. Each fan cube shall be (individually wired to
a control panel containing a single VFD, as specified elsewhere, for the total connected HP for
all fan motors contained in the FWT array) (wired to an individual VFD as specified elsewhere
for each fan motor. Each individual VFD shall be controlled by a PLC. Wire sizing shall be
determined, and installed, in accordance with applicable NEC standards.
8.3. The Fan Wall array shall produce a uniform air flow profile and velocity profile within the
airway tunnel of the air handling unit not to exceed the specified cooling coil and/or filter
bank face velocity when measured at a point 12” from the intake side of the Fan Wall array
intake plenum wall, and at a distance of 48” from the discharge side of the Fan Wall intake
plenum wall.
8.4. Each fan/motor assembly shall be removable through a 30” wide, free area, access door
located on the (discharge) (inlet) side of the fan wall array.
8.5. FANWALL Technology Motor
8.5.1.Provide FANWALL Technology permanent magnet (PM) motors.
8.5.2.The motor running off a VFD motor shall have tested performance efficiencies equal to
those listed in the FANWALL PM motor columns in the table below.
Motor efficiency at
Nominal speed
Motor
HP
3
5
FANWALL
PM
motor
93.0%
92.0%
NEMA
Premium
induction
motor
89.0%
89.0%
Motor efficiency at reduced speed on system curve
67% speed
50% speed
33% speed
FANWALL
PM
motor
92.5%
93.0%
NEMA
Premium
induction
motor
84.0%
86.0%
FANWALL
PM
motor
90.5%
91.5%
NEMA
Premium
75.0%
79.0%
FANWALL
PM
motor
84.0%
87.0%
NEMA
Premium
induction
motor
58.0%
62.0%
8.5.3.The motor shall incorporate conical rotor and stator geometry to concentrate axial flux
paths and utilize all ferrite magnets. The motor shall have compact bobbin-type windings
(end-turns on the windings are not permitted).
8.5.4.The motor shall have NEMA T frame foot mounting and comply with NEMA MG1
dimensional requirements. External rotor motors are not permitted.
8.5.5.The motor shall be UL Listed and authorized to apply the UL mark. The motor windings
shall have a minimum voltage spike resistance rating of 2400V.
8.5.6.Each motor in the FANWALL unit shall be driven off a dedicated variable frequency drive
that is programmed and tested at the factory. Acceptable drives are the FANWALL
Technology Drive, ABB ACS355 and Yaskawa V1000.
8.5.7.The motor shall have permanently lubricated sealed or double-shielded ball bearings.
8.5.8.The motor shall incorporate a means to mitigate induced shaft currents to prevent
electrical arcing across bearing races and balls via a contacting grounding stick. Fiber type
grounding devices are not permitted.
8.6. Option: Each fan/motor “cube” will be provided with an individual back-draft damper. 6063T5 extruded aluminum frame and blades. Blades will have solid rubber blade edge seal.
Bearings shall have rubber shielded radial ball bearing, permanently lubricated.
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Last Rev: 2/12/2016 Page 5 of 10
8.7. Option: Each fan assembly shall be supplied with a complete flow measuring system, Huntair
Flow-Cone, which indicates airflow in Cubic Feet per Minute. The flow measuring system shall
consist of a flow measuring station with two static pressure taps and two total pressure tubes
located at the throat of the fan inlet cone. The flow measuring station shall not obstruct the
inlet of the fan and shall have no effect on fan performance (flow or static) or sound power
levels. A surface mounted indicator, located on the unit exterior, shall provide a (digital)
(analog) CFM readout, and/or a (4-20 ma) (0-10 volt) output control signal for use in the BAS
as specified elsewhere.
8.8. The manufacturer shall provide a complete spare FWT fan/motor assembly for emergency
replacement, one for each type of assembly provided on the project. Manufacturers for
alternate, single direct driven fan assembly provided in lieu of the specified Fan Wall shall
provide a spare motor and fan assembly and a five-year, parts and labor warranty for repair
and/or replacement at no additional expense to the owner. Such warranty coverage shall
include all freight charges for expedited shipment of emergency replacement parts, the cost of
any cranes or lifting devices, and any costs associated with air handling unit disassembly and
re-assembly, as required, for emergency replacement of any defective fan or motor.
9. Vibration Testing:
9.1. If factory witness testing is required, a Factory Balance test shall be performed on the fan
assembly to certify that the fan meets the G0.55 balance quality grade, or 0.022 mils/sec zeroto-peak vibration velocity.
Vibration measurements shall be taken in three orthogonal directions: One taken parallel to
shaft in the horizontal plane and two taken perpendicular to the shaft in the horizontal and
vertical planes.
9.2. During balancing, the fan shall be imposed with an operating resistance equal to the design
external static pressure.
9.3. A certificate of compliance signed by the manufacturers Quality Control Inspector shall be
attached to each fan assembly at the factory and incorporated into the operating and
maintenance manuals. Copies of the certified balancing reports shall be provided with the
unit O&M manuals at the time of shipment. Submittals that do not include compliance with
this requirement will be rejected.
10. Coils:
10.1. Chilled and Hot Water shall be of the aluminum plate ripple fin .008, and .010 (.006, .008
.0095, .016 aluminum or copper), extended surface rated in accordance with ARI 410 for
water, steam or ethylene/propylene glycol water mixture. The tubes shall have a minimum
.020-wall thickness (.025, .035 ) of seamless copper expanded into the fin collars to provide a
permanent mechanical bond. No metallic or thermal bonding materials are acceptable. Return
Bends shall be a minimum of one tube thickness greater than the main tubes .049 brazed
replaceable copper (or CuproNickel). “U” type shaped tubes is not acceptable. Coil headers
shall be non-ferrous seamless copper (cast iron headers are not acceptable), and provided
with brass or copper male pipe connections. Pipe connections shall be same end connections.
Each Coils supply & return connections shall be raised / lowered a minimum 6” from the
bottom / top of the coil to allow room for piping connection hookup especially between
stacked coils, coils near floors & coils near roofs. Each coil shall be provided with capped vent
& drain connections extended to the exterior of the cabinet. All coils shall be fully drainable
with no trapped tubes. Coils shall be counter flow design with connections either left or right
© CES Group, LLC CLEANPAK | 19855 SW 124th Ave, Tualatin, OR 97062 | 503.639.0113 | www.huntair.com
Last Rev: 2/12/2016 Page 6 of 10
hand as specified. The use of internal restrictive devices such as turbolater springs or ribbons
to obtain turbulent construction is not acceptable.
10.2. Coil casings shall be minimum 16 gauge galvanized (or 14 gauge, 12 gauge, or 304 Stainless
Steel), with formed 3/4” flanges (or 1-1/2”, 2” or custom) on all sides of the coil with the tube
sheets having pressed or extruded tube holes. The coil casing shall be reinforced so that the
maximum unsupported length is 60”. The reinforcements shall be of the same material as the
casing. Both ends of the coil to be sealed off from the main air stream by full height blank off’s
on both the entering air and leaving air sides. Blank off’s to be the same material as the coil
casing. Headers and return bends to be further insulated with a closed cell neoprene gasket
the full height & width of the coil casing to reduce condensation.
10.3. All coils are tested and rated in accordance with the Air Conditioning and Refrigeration
Institute (ARI) Standard 410 and certified in accordance with the ARI certification program. All
tubes shall be tested at a minimum 450 PSIG and all assemblies tested under water at 450
PSIG for a minimum of 5 minutes and rated for 450 PSIG working pressures. Individual tube
and core tests before installation of header are not considered satisfactory. Hydrostatic tests
alone will not be acceptable.
10.4. Stacked coils: (Option 1) mounted with integral stacking flanges on the coil (Option 2) to be
mounted in racks to allow individual coil removal without interference to other coils. Racks to
be designed to allow coil removal through the roof of the unit if required. All coils to be
removable from either side of the unit by easily removable end panels. Individual end panels
to be supplied for each coil on the Supply & Return side of the cabinet to allow single coil
piping breakdown for coil removal.
10.5. Coil Supply & Return piping connections extending through the cabinet wall shall be sealed by
(caulking) (Rubber Grommets with caulking) (double escutcheon plate) on the exterior of the
casing. The escutcheon plate shall have a rolled collar around the pipe opening to protect the
pipe and be equipped with an “O” ring rubber gasket between the collar and the pipe to
prevent chaffing and provide an air tight seal around the opening.
11. Filters: (Specifier Select)
11.1. Filters shall be arranged for Face, Rear or side loading as indicated on the detail drawings. Face
loading is preferred where space allows. Face or rear loading to be in gasketed Universal
Holding Frames. The filter rack assemblies to blanked off to the sides, roof and floor and
properly sealed to minimize filter bypass.
11.2. The filter Prefilter section shall be factory fabricated as an integral part of the air handling unit.
Filters to be arranged for face (rear) loading into a gasketed Universal holding frame. Filters to
be ...... % Efficient, UL Class 2 (or 1) as manufactured by...... ( ) sets of the filters to be
provided.
11.3. Intermediate and/or High Efficient filters. The filter section shall be factory fabricated as an
integral part of the air-handling unit. Filters to be arranged for face (rear) loading into a
gasketed positive sealing Universal Holding Frame. Filters to be ...... % Efficient, UL Class 2 (or
1) as manufactured by……. ( ) sets of filters to be provided.
11.4. Carbon / Chemical Filters. The filter section shall be factory fabricated for face (rear or side
loading), in a gasketed positive sealing Universal Holding Frame (or the filter manufacturers
tray system). Filters to be……….. as manufactured by ….( ) sets of filters to be provided.
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Last Rev: 2/12/2016 Page 7 of 10
11.5. HEPA Filters. The HEPA filter section shall be factory fabricated for Face Loading of the filters in
the proper HEPA Filter Frame matched to the filter. Filter to be…..% Efficient, UL Class 2 (0r
1) as manufactured by…… ( ) sets of filters to be provided.
11.6. Each filter bank to be provided with a Dwyer Series 2000 Magnehelic Air Filter Gauge with
adjustable signal flag. Gauges to be flush mounted. Exterior unit gauges to be covered with a
weatherproof enclosure to protect the gauge and prevent hazing of the glass.
11.7. Provide walk-in filter access sections upstream / downstream of each filter rack with adequate
space for filter service.
11.8. Filter banks to be sized so maximum filter face velocity does not exceed 500 fpm.
12. Lights/Control Wiring:
12.1. Provide vapor proof marine type 150-watt light fixtures in each accessible section complete
with a protective metal cage and sealed glass enclosure. Lights to be wired to a common
switch mounted in a weatherproof box adjacent to the fan access door complete with a
convenience outlet. Outlet shall have an indicator light. Power shall be 120v/1/60.
12.2. All wiring to lights shall be in conduit and internal to the unit. No external conduit runs for the
lights are allowed.
12.3. Air handler manufacturer shall allow a minimum 1.5” clearance above the entire width of each
interior bulk headers (coils, filters, fan blank off, etc.). This will be to allow wiring of any 110v
or 24v runs internally to the unit as required by the controls contractor and reduce the
number penetrations of the exterior panels.
12.4. If the unit requires splitting, junction boxes shall be furnished at each section to allow the
electrical contractor to make final connections in the field. Wiring to be clearly labeled at
junction points to facilitate reconnection.
13. Dampers:
13.1. Control Dampers:
Furnish and install, at locations shown on plans, or in accordance with schedules, Standard
(Low Leak) Dampers with published leakage data certified under the AMCA certified ratings
program. (Low Leak Dampers shall be rated less than 10 cfm per sq. ft. of area at 4-in. w.g.
pressure difference through a 48” x 48” damper). Standard Control Dampers shall be
constructed of Formed Steel (extruded Aluminum) blades and casing provided with vinyl or
rubber edge seals and stainless steel edge seals. (Low leak dampers shall be fabricated of
minimum 5” x 1” x .125” 6063T5 extruded aluminum hat channel with hat mounting flanges
on both sides of the frame. Blades shall be airfoil type extruded aluminum (maximum 6”
depth) with integral structural reinforcing tube running the full length of each blade. Blade
edge seals shall be extruded vinyl double edge design with inflatable pocket that enables air
pressure from either direction to assist in blade to blade seal. Blades shall be mechanically
locked in extruded blade slots, yet be easily replaceable in the field.) Adhesive or clip-on type
blade seals are not acceptable. Bearings shall be non-corrosive molded synthetic. Axles shall
be square or hexagonal (round is not acceptable) to provide positive locking connection to
blades and linkage. Linkage shall be concealed in the frame.
13.2. Smoke Dampers:
Furnish and install, at locations shown on plans, or in accordance with the schedules a Low
Leak Damper classified as a UL555S Leakage Class I smoke damper, the lowest leakage class
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Last Rev: 2/12/2016 Page 8 of 10
applicable for HVAC smoke control systems. The damper shall bear the UL Label attesting to
the same. As part of the UL qualification, the damper shall have demonstrated a capacity to
operate (to open & close) under HVAC system operating conditions, with pressures up to 4”
w.g. in the closed position, and 4,000-fpm air velocity in the open position. The damper also
fulfills the requirements for smoke dampers per NFPA90A and NFPA92A. Damper must be
equipped with the appropriate electric or pneumatic actuator and be rated as an assembly to
elevated temperatures of 250 degrees F, 350 degrees F or 450 degrees F. depending upon the
actuator selected. In addition, the damper must be factory furnished with the appropriate
damper actuator to provide fail-safe operation (the damper automatically goes to the desired
fail-safe position as fire interrupts power). The damper frame shall be a minimum .125” wall
thickness 5” x 1” 6063T5 aluminum extruded into a structural hat channel shape. The blades
shall be a maximum 6” wide; airfoil shaped 6063T5 heavy gauge single piece extruded
aluminum. Bearings shall be stainless steel sleeve turning in an extruded hole in the frame for
long life. Blade seals shall be silicone rubber mechanically locked into the blade edge
(adhesive or clip fastened seals are not acceptable) and shall be designed to withstand 450
degrees F. Jambs shall be non-corrosive aluminum compression type to further enhance
smoke management.
14. Sound Power Levels:
14.1. The sound power level at the air handling unit discharge, air intake (return air and / or OSA
intake), and casing radiated shall not exceed the values given in the table shown below, when
the unit is operating at maximum design airflow and static Pressure.
Maximum Octave Band sound Power Level in dB RE 10E-12 watts
Unit Tag # ( )
Octave Bands Center Freq. 125 250 500 1k 2k 4k 8k
Unit Inlet
Unit Outlet
Casing Radiated
14.2. It shall be the option of the contractor to provide a quieter fan, acoustical lining, sound traps
or other sound attenuating devices within the air handling unit to supplement the design in
order to meet the specified levels above.
14.3. The air handling units sound power data shall be submitted for approval. The submittal shall
include a complete description of the methods and procedures used to develop the sound
power levels being submitted.
15. Cleaning and Wrapping for Shipment:
15.1. Unit shall be cleaned vacuumed and cleaned both internally and on the exterior with a 50/50
IPA solution utilizing a non-shedding cloth.
15.2. Cleaned unit shall be shipped on an open flat bed truck (covered by a tarp to protect from
road contamination) (double wrapped in plastic and shall be covered by a tarp or enclosed to
protect from road contamination) at shipment.
16. Delivery, Storage & Handling:
© CES Group, LLC CLEANPAK | 19855 SW 124th Ave, Tualatin, OR 97062 | 503.639.0113 | www.huntair.com
Last Rev: 2/12/2016 Page 9 of 10
16.1. Unit shall ship with all openings securely covered with wood and / or nylon reinforced plastic
wrap and to be watertight. Each unit (will be covered by a tarp) and securely strapped down
on an open flatbed truck.
16.2. Units must be stored in a clean dry area and protected from the weather and construction
traffic. Carefully follow manufacturers’ storage instructions if installation does not
immediately follow arrival at the job site.
16.3. Follow manufacturers rigging guidelines for movement and installation of equipment.
17. Warranty:
17.1. Unit manufacturer to warrant it’s product to be free of defects in materials and workmanship
under normal use when installed and operated in accordance with factory recommendations
for a period of 18 months from date of shipment or 12 months after initial equipment startup, whichever occurs first. Equipment found to be defective should be replaced or repaired to
include all parts and labor. Component parts that require periodic replacement due to normal
wear such as filters, fan belts, etc. are not covered by the warranty.
© CES Group, LLC CLEANPAK | 19855 SW 124th Ave, Tualatin, OR 97062 | 503.639.0113 | www.huntair.com
Last Rev: 2/12/2016 Page 10 of 10