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HVAC Air Distribution Devices

Rev8
IssuedAug 29, 2026
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1 Scope

NOTE This standard covers the selection basis, performance criteria, materials, construction, finish, installation, and field verification of room-side air distribution devices - the outlets and inlets at which a ducted or plenum air system meets an occupied space. (1.1)
NOTE Devices covered are supply outlets of every common face configuration, return and exhaust inlets, and transfer openings between spaces, together with the frames, cores, integral dampers, equalizing grids, and finishes furnished as part of the device assembly. (1.2)
NOTE The following are outside the scope of this standard: (1.3)
  • Air terminal units, fan-powered boxes, and their controls upstream of the device, covered by Air Terminal UnitsAir Terminal UnitsResolves to the current adopted revision.sync/air-terminal-units
  • Duct construction, sealing, hangers, and leakage testing, covered by HVAC DuctworkHVAC DuctworkResolves to the current adopted revision.sync/hvac-ductwork
  • Air-handling unit casings, coils, and filter sections, covered by Air Handling UnitsAir Handling UnitsResolves to the current adopted revision.sync/air-handling-units
  • System-wide testing, adjusting, and balancing procedure and report format, covered by Testing Adjusting And BalancingTesting, Adjusting, and Balancing for HVACResolves to the current adopted revision.sync/testing-adjusting-and-balancing
  • Exterior intake and relief louvers set in the building envelope
  • Kitchen exhaust hoods and grease-laden exhaust terminations
  • Fire dampers, smoke dampers, and combination fire and smoke dampers furnished as standalone assemblies rather than integral to a device
  • Unidirectional-flow outlets and terminal HEPA filter housings serving cleanrooms and critical containment spaces
  • Radiant ceiling panels and chilled beams, whose primary thermal exchange is not by air delivery
1.4 Aerodynamic and sound performance cited for any device under this standard shall be derived from testing in accordance with ANSI/ASHRAE 70.
1.5 Occupied-space sound levels attributed to air distribution devices shall be estimated in accordance with ANSI/AHRI 885.
1.6 Air diffusion performance in the occupied zone shall be evaluated by the Air Diffusion Performance Index method of the ASHRAE Handbook - Fundamentals, Space Air Diffusion chapter.

2 Referenced Standards

2.1 Equipment, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
2.2 Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
Standard Title
ANSI/ASHRAE 70 Method of Testing the Performance of Air Outlets and Air Inlets
ANSI/ASHRAE 113 Method of Testing for Room Air Diffusion
ANSI/ASHRAE 55 Thermal Environmental Conditions for Human Occupancy
ANSI/ASHRAE 62.1 Ventilation and Acceptable Indoor Air Quality
ASHRAE Handbook - Fundamentals Space Air Diffusion chapter (ADPI, throw, terminal velocity, characteristic room length)
ANSI/AHRI 885 Procedure for Estimating Occupied Space Sound Levels in the Application of Air Terminals and Air Outlets
ANSI/ASA S12.2 Criteria for Evaluating Room Noise
NFPA 90A Standard for the Installation of Air-Conditioning and Ventilating Systems
ASTM E84 Standard Test Method for Surface Burning Characteristics of Building Materials
ASTM A653 Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process
ASTM A1008 Standard Specification for Steel, Sheet, Cold-Rolled, Carbon, Structural, High-Strength Low-Alloy and High-Strength Low-Alloy with Improved Formability
ASTM A240 Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications
ASTM B209 Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate
ASTM B221 Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
ASTM B244 Standard Test Method for Measurement of Thickness of Anodic Coatings on Aluminum by Eddy-Current Method
ASTM D3359 Standard Test Methods for Rating Adhesion by Tape Test
UL 555 Fire Dampers
UL 555S Smoke Dampers
ICC A117.1 Accessible and Usable Buildings and Facilities

3 Submittals

3.1 Action Submittals

3.1.1 The Contractor shall submit the following for the Engineer of Record's review and return before any device covered by the submittal is procured:
  • Manufacturer product data for each device type, covering face configuration, face and neck dimensions, frame style, base material, finish, core type, and integral accessories
  • Rated performance data for each scheduled device at its scheduled airflow, reporting throw to the 50, 100, and 150 fpm terminal velocities, total pressure at the neck, and radiated sound power, each identified as derived from ANSI/ASHRAE 70 testing
  • Occupied-space sound level estimate for each scheduled device prepared per ANSI/AHRI 885, stating the room correction values used
  • Air Diffusion Performance Index calculation for each typical space type, showing the outlet selected, its position, its scheduled airflow, the characteristic room length used, and the resulting index
  • Finish sample in the specified color for each combination of base material and finish supplied
  • Frame cross-section detail for every ceiling and wall construction into which devices are installed, showing the interface with the finished surface
  • Device schedule keyed to the mechanical drawings, listing tag, device type, face size, neck size, scheduled airflow, frame style, finish, and integral damper
  • Independent support detail for each device whose installed weight exceeds 20 lb
Action Submittals Requiredcheckbox
☑ Product data for each device type
☑ Rated performance data at scheduled airflow
☑ Occupied-space sound level estimate per AHRI 885
☑ ADPI calculation for each typical space type
☑ Finish sample for each material and finish combination
☑ Frame cross-section detail for each ceiling and wall type
☑ Device schedule keyed to the mechanical drawings
☐ Independent support detail for devices over 20 lb
3.1.2 No device shall be released for fabrication or procurement until the submittal covering it has been reviewed and returned.
3.1.3 Where the Contractor proposes a device from a manufacturer other than the one on which the design was based, the submittal shall include a side-by-side comparison of throw, total pressure, and sound power at the scheduled airflow for the proposed and the scheduled device.

3.2 Closeout Submittals

3.2.1 Before final acceptance of the air distribution system, the Contractor shall submit the following:
  • As-built device schedule recording every field substitution together with the review documentation for it
  • Operation and maintenance instructions for removable cores, pattern controllers, and integral dampers, including the procedure for restoring a setting disturbed during maintenance
  • Record of the final integral damper position, pattern controller position, and core orientation at each device
  • Balancing report extract listing the measured airflow at each device, coordinated with Testing Adjusting And BalancingTesting, Adjusting, and Balancing for HVACResolves to the current adopted revision.sync/testing-adjusting-and-balancing
  • Manufacturer warranty documentation covering material and finish
Closeout Submittals Requiredcheckbox
☑ As-built device schedule recording field substitutions
☑ Operation and maintenance instructions for cores, controllers, and dampers
☑ Record of final damper, controller, and core settings at each device
☑ Balancing report extract listing measured airflow at each device
☑ Manufacturer warranty documentation for material and finish

4 Quality Assurance

4.1 Manufacturer Qualifications

4.1.1 Devices shall be produced by a manufacturer that has continuously produced air outlets and inlets for commercial service for not less than five years.
4.1.2 The manufacturer shall publish a catalog covering the full range of devices supplied to the project, including rated performance at each cataloged neck size.
4.1.3 The manufacturer shall maintain replacement cores, pattern controllers, and integral damper assemblies for the devices supplied for not less than ten years after the date of Substantial Completion.

4.2 Basis of Published Performance Data

4.2.1 Published aerodynamic performance shall be derived from testing in accordance with ANSI/ASHRAE 70, and the data sheet shall identify that standard as the basis.
4.2.2 Published sound power shall be derived from testing in accordance with ANSI/ASHRAE 70, and any occupied-space sound level shown shall identify the ANSI/AHRI 885 room correction values used to produce it.
4.2.3 A device whose published performance is not traceable to ANSI/ASHRAE 70 testing shall not be substituted for a scheduled device.
NOTE Sound power and occupied-space sound pressure are different quantities: sound power is a property of the device measured in a laboratory, while the level a listener experiences depends on room absorption, the number of devices, and the distance from the device to the listener. ANSI/AHRI 885 is the method that converts the first into an estimate of the second. (4.2.4)

4.3 Appearance Consistency Within a Visible Ceiling Area

4.3.1 Within any continuous ceiling area visible from a single vantage point, all devices of the same category shall be supplied by one manufacturer.
NOTE Face pattern, border profile, corner detail, and color tint vary between manufacturers by amounts that are invisible on a submittal sheet and obvious in an installed ceiling, which is why the single-source requirement is written per visible area rather than per project. (4.3.2)

4.4 Installed Device Mock-Up

4.4.1 The mock-up requirement for the project shall be as indicated in the datasheet.
Installed Device Mock-Upradio
● Not required
○ One device of each type installed in the actual ceiling assembly with the specified finish
○ One device of each type plus one complete ceiling bay including lighting and sprinkler devices
4.4.2 Where a mock-up is required, the Contractor shall install it before releasing the balance of the device order, and the Architect and the Engineer of Record shall review it for finish match, frame fit, and alignment with the ceiling module.
4.4.3 Where the parties disagree whether an installed mock-up meets the finish match and frame fit requirements, the Architect shall make the initial determination.

5 Room Air Distribution Strategy

5.1 The strategy by which conditioned air is introduced into and removed from the occupied space determines which device families are usable, and it shall be as indicated in the datasheet.
Room Air Distribution Strategyselect
Overhead mixing
Displacement ventilation
Underfloor air distribution
Stratified ventilation in high-bay spaces
NOTE In an overhead mixing system the supply jet is deliberately made energetic enough to entrain and mix the whole room volume, so comfort is governed by throw and by the residual velocity that reaches the occupied zone. (5.2)
NOTE In a displacement or underfloor system the supply air is introduced at low velocity near the floor and rises by buoyancy as it collects heat from occupants and equipment, so comfort is governed by the temperature and velocity of the air at ankle level and by the vertical temperature gradient. (5.3)
NOTE Where ceilings are tall, cooling loads are moderate, and the floor-to-return path is unobstructed by full-height partitions, a displacement outlet delivers ventilation air to the breathing zone before it has mixed with room air, and it does so at a lower supply-to-room temperature difference than an overhead system requires. (5.4)
5.5 Where displacement ventilation is selected and the space sensible cooling load exceeds 30 Btu/h/ft² of floor area, the Engineer of Record shall document the supply air temperature and the resulting floor-level air temperature and speed at the design load.
5.6 Where displacement or underfloor distribution is selected, return and relief openings shall be located at or near the ceiling so the buoyant plume is not short-circuited back into the supply path.

6 Throw, Terminal Velocity, and Occupied-Zone Air Motion

NOTE Throw is the distance from a supply outlet to the point at which the jet has decayed to a stated terminal velocity, and it is the single characteristic that most directly determines whether a room mixes or stagnates. (6.1)
NOTE Three terminal velocities are published for most supply outlets, and each answers a different question: the 150 fpm distance indicates how far the jet stays attached to the ceiling and washes a perimeter surface, the 100 fpm distance indicates the practical reach of the jet across the room, and the 50 fpm distance indicates how far residual motion carries before it falls into the occupied zone. (6.2)
6.3 The terminal velocity at which throw is scheduled and verified shall be as indicated in the datasheet.
Terminal Velocity Basis for Scheduled Throwrange
fpm
50100150
6.4 For overhead mixing systems, the scheduled throw of each supply outlet shall place the jet boundary at the stated terminal velocity within one outlet spacing of the perimeter wall or of the boundary of the opposing outlet, measured at the ceiling plane.
6.5 Air speed within the occupied zone attributable to the supply outlets shall not exceed the limit indicated in the datasheet at the scheduled airflow, evaluated against the draft criteria of ANSI/ASHRAE 55.
Maximum Occupied-Zone Air Speed from Supply Outletsrange
fpm
20304050607080
6.6 Where the occupied zone is evaluated by field measurement rather than by calculation, air speed and air temperature shall be measured in accordance with ANSI/ASHRAE 113.
NOTE Selecting a supply outlet by neck size and airflow alone, without checking throw and sound at that airflow, is the most common origin of the draft and noise complaints that surface after occupancy. (6.7)

7 Air Diffusion Performance Index

NOTE The Air Diffusion Performance Index is the percentage of measurement points in the occupied zone at which the effective draft temperature - a combined measure of local air temperature deviation and local air speed - falls inside the comfort band. It reduces the interaction of throw, room geometry, and load to a single number that can be compared across outlet selections. (7.1)
7.2 Air diffusion performance shall be calculated for each typical space type in cooling mode, and the outlet type, quantity, position, and scheduled airflow shall be adjusted until the index meets the target indicated in the datasheet.
Air Diffusion Performance Index Target for Cooling Moderange
%
707580859095
NOTE An index of 80 is the value ASHRAE research identified as satisfying most occupants of a space with uniform activity and clothing levels, which is why it serves as the reference point rather than as a ceiling. (7.3)
7.4 Where the space sensible cooling load exceeds 30 Btu/h/ft² of floor area, the ratio of throw to characteristic room length shall be selected from the ASHRAE Handbook - Fundamentals tables for the outlet type rather than by proportioning from a lower-load selection.
NOTE Where the target index exceeds 90, meeting it generally calls for more outlets than the scheduled airflow alone requires, or for pattern adjustment at each outlet, because the index becomes sensitive to small departures from the ideal throw ratio. (7.5)
NOTE The index is defined for cooling-mode operation and does not describe heating-mode distribution, which is governed instead by whether the warm jet penetrates to the occupied zone. (7.6)

8 Heating-Mode Supply Air Distribution

NOTE Supply air warmer than the room is buoyant, so it resists the downward component of a ceiling outlet's discharge and tends to remain as a stratified layer against the ceiling while the occupied zone stays cold. (8.1)
8.2 Where a ceiling supply outlet serves both heating and cooling, the Engineer of Record shall verify that the heating-mode jet reaches the occupied zone at the design heating supply temperature.
8.3 Where a ceiling supply outlet serves both heating and cooling in a space with a ceiling height above 12 ft, the outlet shall be furnished with a field-adjustable pattern controller, or heating-mode distribution shall be documented by a separate calculation.
8.4 Where the space is heated by a source other than the ceiling supply outlets, such as perimeter radiation or radiant panels, the outlets need only satisfy the cooling-mode criteria of this standard.

9 Device-Generated Sound

9.1 The occupied-space sound level attributable to each device at its scheduled airflow shall not exceed the limit indicated in the datasheet.
Maximum Device-Generated Sound Level in the Occupied Space (NC)range
152025303540455055
9.2 Where a lower sound limit is indicated for a specific space, that limit shall govern in that space.
NOTE Sound criteria vary by how the space is used, and the ranges commonly applied are: (9.3)
  • NC 25 to NC 30 for performance spaces, recording and broadcast rooms, and executive offices
  • NC 30 to NC 35 for private offices, classrooms, conference rooms, and patient rooms
  • NC 35 to NC 40 for open offices, libraries, retail sales areas, and restaurants
  • NC 40 to NC 45 for corridors, lobbies, and light industrial spaces
  • NC 45 to NC 50 for kitchens, gymnasiums, and mechanical and service areas
9.4 The method used to convert published device sound power into an occupied-space level shall be as indicated in the datasheet.
Occupied-Space Sound Level Estimating Methodradio
● Published device sound level using the AHRI 885 default room correction
○ Project-specific AHRI 885 calculation by the Engineer of Record
NOTE The default room correction embedded in published selection tables assumes a room of ordinary absorption with the listener a stated distance from the device, so it understates the level reached in a hard-surfaced, reverberant space such as an atrium, a lobby, or a natatorium. (9.5)
9.6 Where the project-specific estimating method is selected, the calculation shall use the room absorption, device quantity, and listener distance of the actual space, and shall be included in the action submittal.
9.7 Where an integral damper is throttled, it generates sound that the device's own rating does not include, so the sound estimate shall be made at the throttled position expected at final balance rather than at the wide-open position.
9.8 Sound criteria expressed as NC values shall be evaluated by the tangent method of ANSI/ASA S12.2 where field measurement is performed.

10 Airflow Resistance at the Device

10.1 The total pressure required to deliver the scheduled airflow through the device is the device's contribution to the system resistance the fan must overcome, and it shall not exceed the limit indicated in the datasheet at the scheduled airflow.
Maximum Device Total Pressure at Scheduled Airflowrange
in. w.g.
0.020.050.0750.10.150.20.250.30.40.5
NOTE Device pressure, sound, and throw move together: forcing a given airflow through a smaller neck raises all three at once, so a limit set tight enough to protect fan energy also constrains how far the selection can be pushed for throw. (10.2)
10.3 The total pressure of each device at its scheduled airflow shall be included in the fan external static pressure calculation for the system it serves.
10.4 Where an integral damper is provided, the pressure used in the fan calculation shall be the pressure at the throttled position expected at final balance.

11 Supply Outlet Types

11.1 Square and Rectangular Face Outlets

NOTE A square or rectangular face outlet discharges a horizontal jet in one, two, three, or four directions across the ceiling, where it attaches to the ceiling surface and decays along the throw distance. (11.1.1)
NOTE The discharge pattern is fixed by the core installed in the outlet, and one-way, two-way, and three-way patterns are used where an adjacent wall or a neighboring outlet would otherwise be washed by the jet. (11.1.2)
11.1.3 The discharge pattern of each square and rectangular face outlet shall be selected so that no jet is directed at a wall closer than the throw to the scheduled terminal velocity, and so that opposing jets from adjacent outlets do not collide within the occupied zone.
11.1.4 Where a square or rectangular face outlet serves a space in heating mode with no other heat source, it shall be furnished with a pattern controller capable of a downward discharge.

11.2 Round Face Outlets

NOTE A round face outlet discharges radially through a full circle and produces a uniform horizontal throw in every direction, which suits an open area with no near wall on any side. (11.2.1)
11.2.2 A round face outlet shall not be located closer to a wall than its throw to the scheduled terminal velocity unless it is furnished with a sectored core that blanks the discharge toward the wall.

11.3 Linear Slot Outlets

NOTE A linear slot outlet discharges through one or more narrow continuous slots and produces a long, thin jet, which suits washing a glazed perimeter, articulating the edge of a soffit, and running in line with linear light fixtures in an exposed ceiling. (11.3.1)
NOTE The number of slots changes the trade between reach and sound at a fixed airflow: adding slots at the same total airflow lowers the discharge velocity through each, which reduces generated sound and shortens throw, while removing slots does the reverse. (11.3.2)
11.3.3 Inactive lengths within a continuous linear slot run shall be blanked off internally by the manufacturer so that the exposed slot appears continuous while air is discharged only along the active length.
11.3.4 Sections joined to form a continuous linear slot run shall be aligned with concealed splines or alignment pins so that no offset between adjacent sections is visible along the run.
11.3.5 End conditions at the extremities of a continuous linear slot run shall be coordinated with the Architect before fabrication.
11.3.6 Where a linear slot outlet serves a space in both heating and cooling modes, it shall be furnished with a pattern controller that biases the jet horizontally in cooling and downward in heating.

11.4 Swirl Outlets

NOTE A swirl outlet imparts rotation to the discharge, which induces room air into the jet at a high rate and collapses the temperature difference within a short distance of the outlet. (11.4.1)
NOTE Where ceilings are high enough that a horizontal-discharge outlet would over-throw the space, or where the supply-to-room temperature difference is large, the rapid induction of a swirl outlet brings the jet close to room temperature before it descends into the occupied zone. (11.4.2)
11.4.3 Where swirl outlets are used with a variable-air-volume system, the selection shall be verified at the minimum scheduled airflow as well as at the maximum, because the induction that makes the outlet work falls off with discharge velocity.

11.5 Displacement Outlets

NOTE A displacement outlet has a large free area and discharges at a face velocity low enough that the supply air spreads across the floor as a shallow layer rather than as a jet. (11.5.1)
11.5.2 Displacement outlets shall be located so that no seated occupant is within the near-floor spreading zone published by the manufacturer for the scheduled airflow.
11.5.3 Displacement outlets shall be protected from impact where they are floor-mounted in circulation paths, by a bollard, a recess, or a reinforced face section.
NOTE Furniture, full-height partitions, and stored material placed against a displacement outlet defeat the floor-level spreading the outlet depends on, so the clear zone in front of the outlet is a coordination item with the furniture layout rather than a property of the device. (11.5.4)

11.6 Light-Fixture-Integrated Outlets

NOTE A light-fixture-integrated outlet combines a luminaire body and a slot outlet in one ceiling unit, discharging along the long edges of the fixture from a duct collar at its back. (11.6.1)
11.6.2 The Contractor shall confirm at submittal that the integrated outlet is compatible with the luminaire supplied under the electrical scope, including the lamp or driver compartment, the ceiling module, and the sequence in which each trade installs its portion.
11.6.3 The scheduled airflow at a light-fixture-integrated outlet shall be verified against the outlet's rated sound at that airflow, because the slot free area available within a luminaire body is smaller than that of a comparable standalone slot outlet.

12 Return and Exhaust Inlets

NOTE An inlet draws air from a region close to its face rather than from across the room, so its location has far less effect on room air motion than a supply outlet's does. Its consequential failure mode is short-circuiting - drawing supply air back before it has served the occupied zone. (12.1)
12.2 Return and exhaust inlets shall be located so that supply air is not drawn directly from a supply outlet into an inlet without passing through the occupied zone.
12.3 The core style of return and exhaust inlets shall be as indicated in the datasheet.
Return and Exhaust Inlet Core Styleradio
● Eggcrate core, 1/2 in. × 1/2 in. cell
○ Eggcrate core, 1/2 in. × 1 in. cell
○ Fixed horizontal blade louver
○ Fixed 45° deflection blade louver
○ Perforated face with concealed back-pan
○ Perforated face matching the supply outlet face pattern
12.4 The net face velocity through a return or exhaust inlet at its scheduled airflow shall not exceed the limit indicated in the datasheet.
Maximum Net Face Velocity at Return and Exhaust Inletsrange
fpm
200250300350400450500550600700800
NOTE Net face velocity is computed on free area rather than on nominal face area, and the two differ by a factor that depends on the core style, so an inlet sized on nominal area alone runs faster and louder than intended. (12.5)
12.6 Where an inlet is within the acoustically sensitive area of a space with a sound limit of NC 30 or lower, the face velocity shall be selected at the lower end of the permitted range so that the inlet does not become the governing sound source.
12.7 Where an exhaust duct conveys moisture, fumes, or condensate that would corrode a dissimilar metal at the connection, the inlet shall be of the same material as the duct it serves.

13 Transfer Openings Between Spaces

NOTE A transfer opening moves air between two adjacent spaces without dedicated ductwork, most often relieving supply air from a private space into a corridor or plenum that serves as the return path. (13.1)
NOTE An untreated transfer opening carries speech as readily as it carries air, so a direct louver between a private space and a corridor removes the acoustic separation the partition was built to provide. An acoustically treated transfer assembly interposes a lined, baffled plenum between the two faces, which absorbs speech-frequency sound while leaving a low-resistance airflow path. (13.2)
13.3 Transfer openings between a space with a speech-privacy requirement and an adjoining space shall be acoustically treated assemblies.
13.4 A transfer opening shall not penetrate a fire-rated or smoke-rated assembly unless a damper listed to UL 555 or UL 555S, as applicable to the rating, is installed in the penetration.
13.5 The Contractor shall confirm the rating of every assembly through which a transfer opening passes before cutting the opening.
13.6 Transfer openings shall not be installed in an assembly enclosing an exit stair, an exit passageway, or an elevator hoistway.

14 Device Materials for Service Environments

14.1 Devices in Dry Interior Spaces

14.1.1 The base material of devices serving dry interior spaces shall be as indicated in the datasheet.
Device Material for Dry Interior Spacesselect
Steel sheet
Extruded or formed aluminum
Type 304 stainless steel
Type 316 stainless steel
Manufacturer's standard (by default)
NOTE Steel, aluminum, and stainless steel all perform indefinitely in a dry conditioned interior, and manufacturers build different device families in different base metals, which is why the material for ordinary interior service can be left to the manufacturer's standard offering for the device type selected. (14.1.2)
14.1.3 Where the datasheet leaves the material for dry interior spaces to the manufacturer, the manufacturer shall state the base metal supplied for each device type in the action submittal.
14.1.4 Steel devices shall be zinc-coated to ASTM A653 or cold-rolled to ASTM A1008 with a corrosion-inhibiting primer applied before the finish coat.
14.1.5 Aluminum devices shall be sheet to ASTM B209 or extruded profile to ASTM B221.
14.1.6 Stainless steel devices shall be sheet to ASTM A240 in the type indicated in the datasheet.

14.2 Devices in Wet and High-Humidity Spaces

14.2.1 The base material of devices serving showers, locker rooms, natatoriums, commercial kitchens, laundries, and comparable spaces shall be as indicated in the datasheet.
Device Material for Wet and High-Humidity Spacesselect
Extruded or formed aluminum
Type 304 stainless steel
Type 316 stainless steel
Powder-coated steel sheet with sealed edges
NOTE A painted steel device in a sustained-moisture environment corrodes first at sheared edges and at fastener penetrations, where the coating is thinnest or broken, and the visible face can stay presentable for several years while the frame behind it is already failing. (14.2.2)
14.2.3 Where a natatorium or any space treated with chlorine-based or bromine-based water chemistry is served, devices shall be Type 316 stainless steel and all exposed fasteners shall be of the same alloy.

14.3 Devices in Corrosive Exhaust Service

14.3.1 The base material of devices serving laboratory exhaust, chemical storage, battery rooms, and comparable corrosive environments shall be as indicated in the datasheet.
Device Material for Corrosive Exhaust Serviceselect
Type 316 stainless steel
Type 304 stainless steel
Extruded or formed aluminum
Epoxy-coated steel sheet
Molded fiberglass-reinforced polyester
Polypropylene or PVC
NOTE Aluminum resists many corrosive atmospheres but is attacked by both strongly alkaline and chloride-bearing solutions, so it holds up in an environment whose specific chemistry has been checked against it and not as a general substitute for stainless steel. (14.3.2)
14.3.3 Devices of fiberglass-reinforced polyester, polypropylene, or PVC installed in a plenum or in a ceiling assembly regulated by NFPA 90A shall have a flame spread index not greater than 25 and a smoke developed index not greater than 50 when tested to ASTM E84.
14.3.4 The Engineer of Record shall confirm the exhaust stream chemistry against the manufacturer's chemical resistance data before the material selection is released for fabrication.

14.4 Sheet Thickness and Fabrication

14.4.1 Steel device faces shall be not lighter than 22 gauge and steel device frames not lighter than 20 gauge.
14.4.2 Aluminum device faces and frames shall be not less than 0.040 in. thick, and linear slot bodies and continuous frames shall be extruded profiles.
14.4.3 Stainless steel device faces shall be not lighter than 22 gauge and stainless steel frames not lighter than 20 gauge.
14.4.4 Where any face dimension of a device exceeds 24 in., the face and frame thickness shall be increased as required to hold the face flat within 1/16 in. across its span under the scheduled airflow.
14.4.5 Exposed surfaces shall be free of burrs, sharp edges, weld spatter, and visible weld seams.
14.4.6 Fasteners on exposed surfaces shall be flush with the face and finished to match it.
14.4.7 Concealed fasteners securing back-pans, collars, and internal components may be plated carbon steel except where the device material is stainless steel, in which case they shall be of the same alloy as the device.

15 Exposed Finishes

15.1 The exposed finish of devices shall be as indicated in the datasheet.
Exposed Finishselect
Powder-coat white
Powder-coat off-white
Powder-coat black
Powder-coat custom color to the Architect's selection
Clear anodized
Color anodized
No. 4 satin stainless steel
Mill finish
NOTE A white or off-white powder coat is used on most ceiling devices because it disappears against the acoustical tile it sits in, and manufacturers hold their standard white close to the common tile whites for that reason. (15.2)
NOTE A mill finish leaves the base metal uncoated, so it carries no color match to the surrounding surface and shows fabrication marks and handling scuffs; it is used where the device face is not architecturally exposed. (15.3)
15.4 Powder coating shall be electrostatically applied and oven-cured over a cleaned and pretreated substrate.
15.5 Powder coat adhesion shall meet a classification of not less than 4B when tested to ASTM D3359.
15.6 Anodized finishes shall be applied only to aluminum devices, and the anodic coating thickness shall be not less than 0.7 mil verified to ASTM B244.
15.7 A No. 4 satin finish shall be applied only to stainless steel devices, and the graining direction shall be consistent across every device in a continuous visible area.
15.8 Where a custom color is selected, the manufacturer's color-match program shall be used and a production sample shall be submitted for the Architect's approval before the order is released.
15.9 Where devices in one visible area are supplied in more than one base material with the same specified color, the Contractor shall submit a sample of each material finished in that color, since the same coating over steel, aluminum, and stainless steel does not necessarily read as the same color.
15.10 Gaskets, sealing strips, and foam inserts within a device installed in a plenum or in a ceiling assembly regulated by NFPA 90A shall have a flame spread index not greater than 25 and a smoke developed index not greater than 50 when tested to ASTM E84.
15.11 The exposed border fastening method shall be as indicated in the datasheet.
Exposed Border Fasteningradio
● Exposed countersunk fasteners finished to match the face
○ Concealed fasteners with a spring-latch or hinged face

16 Cores, Dampers, and Integral Accessories

16.1 Discharge Pattern Adjustment

16.1.1 The means by which the discharge pattern of supply outlets may be changed after installation shall be as indicated in the datasheet.
Discharge Pattern Adjustment at Supply Outletsselect
Factory-fixed pattern determined by the outlet model
Interchangeable removable core
Field-adjustable pattern controller
Interchangeable removable core with a field-adjustable pattern controller
NOTE A removable core lets the discharge direction be changed from below the ceiling without disturbing the device, the duct connection, or the ceiling tile, which matters most during balancing and in tenant fit-outs where the room layout changes after the ceiling is built. (16.1.2)
16.1.3 A removable core shall be retained by captive fasteners or a positive latch, and shall not rely on gravity or friction alone to stay seated.
16.1.4 A field-adjustable pattern controller shall hold its set position against the discharge velocity at the scheduled airflow without additional fastening.
16.1.5 The position of every adjustable core and pattern controller shall be set during balancing and recorded on the closeout record of settings.

16.2 Integral Volume Dampers

16.2.1 The integral volume damper provided at devices shall be as indicated in the datasheet.
Integral Volume Damper at the Deviceradio
● Opposed-blade damper at each supply device
○ Opposed-blade damper at each supply device and each return device
○ Butterfly damper at each round-neck supply device
○ No integral damper at the device
NOTE An integral damper throttles at the point where the air is about to enter the room, so the sound it generates is not attenuated by any duct run before it reaches the listener. A duct-mounted damper placed several diameters upstream generates comparable sound but delivers far less of it to the occupied space. (16.2.2)
16.2.3 Primary balancing of each branch shall be performed at duct-mounted volume dampers provided under HVAC DuctworkHVAC DuctworkResolves to the current adopted revision.sync/hvac-ductwork.
16.2.4 Integral dampers at devices shall be used for final trim within 20% of the scheduled airflow and shall not be used to absorb a branch imbalance.
16.2.5 Unless the datasheet selects a device without an integral damper, an integral damper shall not be installed as the only means of adjusting airflow on a branch serving more than one device.
16.2.6 The access provided to the integral damper operator shall be as indicated in the datasheet.
Integral Damper Operator Accessradio
● Adjustable through the device face
○ Adjustable through the device neck with a key
○ Not applicable where no integral damper is provided

16.3 Equalizing Grids and Duct Take-Offs

NOTE An equalizing grid is a set of adjustable blades set in the device neck that redistributes an uneven approach velocity across the neck before the air reaches the face. (16.3.1)
16.3.2 An equalizing grid shall be provided at each supply device whose neck is served by less than three neck diameters of straight duct.
NOTE Without an equalizing grid, a device fed through a boot, a hard elbow, or a sharply bent flexible duct discharges more air on one side of the face than the other, which skews the pattern and shortens the throw on the starved side. (16.3.3)
16.3.4 Branch take-offs at the main duct shall be furnished and installed under HVAC DuctworkHVAC DuctworkResolves to the current adopted revision.sync/hvac-ductwork, and the Contractor shall confirm before fabrication that no take-off fitting has been assumed to arrive with the device order.

16.4 Insulated Back-Pans and Condensation Control

16.4.1 The back-pan insulation provided at supply devices shall be as indicated in the datasheet.
Back-Pan Insulation at Supply Devicesradio
● Not required
○ Factory-applied back-pan insulation at supply devices
○ Field-applied back-pan insulation at supply devices
NOTE A supply device carrying cold air through a humid ceiling plenum can drop the back-pan below the plenum dew point, and the resulting condensation runs down the neck and stains the ceiling tile from above before anything is visible on the face. (16.4.2)
16.4.3 Where the ceiling plenum is unconditioned, is open to outdoor air, or is in a space whose plenum dew point exceeds the design supply air temperature, supply device back-pans shall be insulated.
16.4.4 Insulation applied to a device back-pan shall be sealed at all edges and penetrations so that no insulation face is exposed to the airstream.

16.5 Security and Anti-Ligature Construction

16.5.1 Security and anti-ligature construction at devices shall be as indicated in the datasheet.
Security and Anti-Ligature Constructionradio
● Not required
○ Anti-ligature construction for behavioral health areas
○ Security construction for detention and holding areas
○ Security construction with an integral fire or smoke damper
16.5.2 Anti-ligature construction shall present no exposed edge, projection, gap, or fastener head capable of anchoring a cord or fabric, and all exposed edges shall be radiused or chamfered and all fasteners recessed below the face.
16.5.3 Security construction shall be of heavy-gauge steel or stainless steel with a perforation pattern that passes the scheduled airflow while preventing the passage of contraband.
16.5.4 Devices in security and anti-ligature construction shall be secured with fasteners whose drive tool is not sold through general retail distribution, and two drive tools per fastener type shall be turned over to the Owner at Substantial Completion.
16.5.5 Where a device in security construction also serves as a fire or smoke damper, the assembly shall be listed to UL 555 or UL 555S as applicable to the rating of the assembly it penetrates.
16.5.6 Security and anti-ligature devices shall be attached to structure or to solid backing, not to the ceiling suspension system.

17 Device Scheduling and Ceiling Coordination

17.1 Each device shall be furnished for the tag, device type, face size, neck size, scheduled airflow, frame style, finish, and integral damper listed in the air outlet schedule. the air outlet schedule
17.2 Device locations, orientation, and position within the ceiling module shall be as shown on the reflected ceiling plan. the reflected ceiling plan
NOTE Face size, neck size, and airflow are project-sized quantities established device by device during design; the template values in this standard are the criteria those sizes are chosen to satisfy, not the sizes themselves. (17.3)
17.4 The Contractor shall participate in overhead coordination for every ceiling area, resolving the positions of devices, luminaires, sprinkler heads, speakers, and detectors against one another before any ceiling suspension is installed.
NOTE Relocating a device after the ceiling grid is set to clear a conflict leaves it out of the module and visibly out of line with its neighbors, which is why the conflict has to be found on the coordination drawing rather than in the field. (17.5)
17.6 Where a conflict cannot be resolved without moving a device out of its scheduled position, the Contractor shall obtain the Engineer of Record's acceptance of the revised position before installing it.

18 Installation

18.1 Support of Devices in Suspended Ceilings

18.1.1 Each device installed in a suspended ceiling shall be independently supported from the building structure above.
18.1.2 The lay-in flange of a device shall locate the device within the ceiling module and shall not carry the weight of the device or of the duct connected to it.
18.1.3 Not less than two supports shall be provided from structure to the device frame at diagonally opposite corners.
18.1.4 Where the installed weight of a device including its connected duct exceeds 20 lb, supplementary support shall be provided in accordance with the manufacturer's published support detail.
18.1.5 Devices shall be installed plumb and square within the ceiling module, with the face flush with the surrounding ceiling surface within 1/16 in.

18.2 Devices in Hard-Surface Ceilings and Walls

18.2.1 Openings in gypsum board, plaster, wood, and masonry surfaces shall be cut to the manufacturer's published rough opening dimension.
18.2.2 An opening cut oversize shall be reframed and the surface repaired to match the adjacent finish, and shall not be closed with sealant, shims, or an oversized border.
18.2.3 Plaster frames shall be furnished by the device manufacturer and shall be set to the finished plaster elevation before plaster work begins.
18.2.4 The Contractor shall notify the plastering trade of each plaster frame location and elevation before the frames are set.
18.2.5 Wall-mounted devices in an accessible route shall be installed so that no part of the device projects into the route beyond the limit permitted by ICC A117.1.

18.3 Duct Connection at the Device

18.3.1 Each device shall be connected to the duct system through a sheet metal collar matching the device neck dimension.
18.3.2 The joint between the collar and the device neck shall be mechanically fastened by band clamp, screws, or flange, and shall be sealed to the seal class established for the duct system in HVAC DuctworkHVAC DuctworkResolves to the current adopted revision.sync/hvac-ductwork.
18.3.3 Flexible duct connections at devices shall comply with the support, bend radius, and maximum length provisions of HVAC DuctworkHVAC DuctworkResolves to the current adopted revision.sync/hvac-ductwork.
18.3.4 The last section of duct entering a device neck shall be straight and concentric with the neck for not less than one neck diameter, unless an equalizing grid is provided at that device.
NOTE A flexible duct compressed, kinked, or bent through a radius tighter than its rated minimum at the device connection loses a large fraction of the airflow the branch was sized to deliver, and no amount of balancing at the device recovers it. (18.3.5)

18.4 Sealing at the Device Frame

18.4.1 Where a supply device is installed in a ceiling whose plenum serves as a return air path, the device frame shall be sealed continuously to the ceiling surface.
NOTE An unsealed supply device frame in a return plenum lets conditioned supply air pass directly around the border into the return without ever entering the room, which appears at balancing as a device that cannot reach its scheduled airflow. (18.4.2)
18.4.3 Where a device is installed in a ducted-return ceiling, the frame shall be seated on a continuous gasket or sealant bead so that no gap is visible at the border and no flanking sound path is left around the device.

18.5 Protection During Construction

18.5.1 Devices shall remain in the manufacturer's packaging until the ceiling or wall surface in which they are installed is complete.
18.5.2 Devices installed before adjacent finishing work is complete shall be covered and protected from dust, paint overspray, plaster, and impact.
18.5.3 Devices soiled during construction shall be cleaned by a method the manufacturer approves for the finish supplied.
18.5.4 Abrasive cleaning and solvent cleaning that dulls, softens, or removes the specified finish shall not be used.
18.5.5 Where a device cannot be restored to match the adjacent devices in the same visible area, it shall be replaced at the expense of the party responsible for the damage.
18.5.6 Where the parties disagree whether a cleaned device matches the adjacent devices, the Architect shall make the initial determination.

19 Field Testing and Balancing

19.1 Airflow Balancing at Devices

19.1.1 The airflow at each device shall be measured and adjusted to the scheduled value within the tolerance indicated in the datasheet, applied as a plus-or-minus band about the scheduled airflow.
Air Balance Tolerance at Each Devicerange
%
5101520
19.1.2 Balancing shall be performed with the system clean, the design filter media installed, all ceiling tiles in place, and every device in its final installed condition.
19.1.3 The balancing contractor shall set each integral damper, pattern controller, and adjustable core, and shall record the final position of each.
19.1.4 Measured airflow, final damper position, and final pattern setting shall be reported for each device in accordance with Testing Adjusting And BalancingTesting, Adjusting, and Balancing for HVACResolves to the current adopted revision.sync/testing-adjusting-and-balancing.
19.1.5 Where a device cannot be brought within tolerance by adjustment at the device and at its branch damper, the balancing contractor shall report the condition to the Engineer of Record rather than throttling the device further.

19.2 Verification of Discharge Pattern

19.2.1 In spaces with a non-rectangular plan, a ceiling height above 12 ft, or a stated comfort requirement, the discharge pattern at each supply outlet shall be verified by smoke visualization or by anemometer traverse after balancing is complete.
19.2.2 Devices with an adjustable pattern shall be reset as required to produce the pattern the design assumed.
19.2.3 A device with a factory-fixed pattern that does not produce the design pattern shall be replaced with a device of the correct pattern at no cost to the Owner.

19.3 Field Verification of Sound Levels

19.3.1 Field verification of device-generated sound shall be as indicated in the datasheet.
Field Verification of Device-Generated Soundradio
● Not required
○ Required in spaces with a sound limit of NC 30 or lower
○ Required in a representative space of each space type
○ Required in every space served by the system
19.3.2 Where field verification is required, sound pressure shall be measured in octave bands at the listener position with the system operating at the scheduled airflow and with the space otherwise quiet, and the result shall be evaluated to ANSI/ASA S12.2.
19.3.3 Where a measured level exceeds the specified limit and the excess is attributable to the device or its installation, the Contractor shall correct the condition and shall bear the cost of re-measurement.
19.3.4 Where a measured level exceeds the specified limit and the excess is attributable to a sound source outside the scope of this standard, the Engineer of Record shall determine the responsible scope.

19.4 Ceiling Smudge Inspection

19.4.1 After not less than 90 days of system operation following occupancy, the ceiling surface around each ceiling-mounted supply outlet shall be inspected for smudging.
NOTE Smudging is airborne dust deposited on the ceiling where the supply jet entrains room air past the outlet face. The pattern it leaves is a record of the actual discharge direction, so it exposes a pattern controller that has shifted, a damaged face, and a room dust load higher than the design assumed. (19.4.2)
19.4.3 Where smudging is found, the Contractor shall clean the affected ceiling surface and shall report the discharge pattern the smudge indicates to the Engineer of Record.
19.4.4 Where the smudge pattern shows that a device is discharging other than as set at balancing, the device shall be reset and the cause corrected under the warranty.

20 Delivery, Storage, and Handling

20.1 Devices shall be delivered in the manufacturer's packaging with each unit marked with its project device tag.
20.2 Devices shall be stored indoors in a clean, dry, weather-protected space until installation.
20.3 Devices shall not be stacked in a manner that deforms a face panel or racks a frame.
20.4 Removable cores, pattern controllers, and loose accessories shall remain in their packaging until immediately before installation.
20.5 Where the building is not dried in or the ceiling is not ready to receive devices, the Contractor shall hold the devices in protected storage rather than installing them.

21 Device Identification

21.1 Each installed device shall correspond to the device tag shown in the air outlet schedule.
21.2 Where an installed device differs from the scheduled device, the as-built device schedule shall record the device actually installed.
21.3 Identification of devices for the Owner's maintenance staff shall be by the air outlet schedule and the as-built mechanical drawings.
21.4 Labels, tags, and markings applied to the exposed face of a device shall be removed before Substantial Completion.

22 Warranty

22.1 The Contractor shall warrant the devices and their installation, including frame fit, alignment, integral damper operation, and core retention, for the period indicated in the datasheet, beginning at the date of Substantial Completion.
Device and Installation Warranty Periodrange
years
1235
22.2 The Contractor shall warrant the exposed finish against peeling, blistering, chalking, and color shift for the period indicated in the datasheet, beginning at the date of Substantial Completion.
Exposed Finish Warranty Periodrange
years
123510
22.3 Warranty coverage shall include the cost of removing and reinstalling the ceiling, wall, and duct work disturbed to reach a device being repaired or replaced, and the cost of repairing collateral damage caused by that work.
22.4 Where a device is repaired or replaced under warranty, the repaired or replacement device shall carry a fresh warranty of the full original period from the date of the repair, or the remainder of the original period, whichever ends later.
22.5 Finish failure on a device exposed to direct sunlight through glazing shall be covered where the exposure is within the limit the manufacturer publishes for the finish supplied.

23 Spare Parts

23.1 The Contractor shall deliver the following to the Owner at Substantial Completion:
  • One spare core for each removable-core outlet model installed
  • One spare pattern controller for each adjustable-pattern outlet model installed
  • Two operator keys or tools for each integral damper access type installed
  • Touch-up coating in each specified color, not less than 4 oz per color
  • Two drive tools for each security or anti-ligature fastener type installed
Spare Parts at Substantial Completioncheckbox
☑ One spare core for each removable-core outlet model
☑ One spare pattern controller for each adjustable-pattern outlet model
☑ Two operator keys or tools for each integral damper access type
☑ Touch-up coating in each specified color, 4 oz minimum
☐ Two drive tools for each security or anti-ligature fastener type
23.2 Spare parts shall be delivered in labeled containers identifying the device model, the device tags they serve, and the date of delivery.
23.3 Touch-up coating for a custom color shall be ordered with the original device order so that the touch-up supply and the installed devices come from the same coating batch.

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