6.6104.1 Outdoor Supply Air Handling Unit Serving Multiple Dwelling Units or Corridors (All Building Types) | Standard Work Specifications for Home Energy Upgrades

Topic:

Supply

Subtopic:

Supply Ventilation Systems

Desired Outcome:

Air handling unit system installed to provide required ventilation

Note:

The authority having jurisdiction may require that a licensed professional perform certain tasks outlined in this detail.

For supporting material, see Referenced Standards.

Multifamily Homes

Title	Specification(s)	Objective(s)
6.6104.1a Pre-inspection	Specifications will be field verified as appropriate to site conditions by installer	Ensure appropriate design for installation
6.6104.1b Air flow	ASHRAE ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers, www.ashrae.org 62.2 and local code requirements should be followed for identifying design airflow rates within apartment dwelling units. All other areas will follow local code requirements and/or ASHRAE ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers, www.ashrae.org 62.1 requirements Air flows will be measured in accordance with ANSI ANSI American National Standards Institute, www.ansi.org / ACCA ACCA Air Conditioning Contractors of America, www.acca.org Standard 5 or ANSI ANSI American National Standards Institute, www.ansi.org / ASHRAE ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers, www.ashrae.org Standard 111 and adjusted to meet design requirements	Provide sufficient outdoor air to desired locations
6.6104.1c Fan specification	Motors 1 horsepower or larger will meet NEMA premium efficiency standards Fan will be capable of maintaining a minimum operating static pressure of .25 inches of water column	Ensure proper flow rate of outdoor air fans Ensure energy efficient delivery of outdoor supply air
6.6104.1d Intake location	Intake will be installed in accordance with all applicable code requirements and/or the most current version of ASHRAE ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers, www.ashrae.org 62.2	Ensure occupant health and safety Prevent entry of contaminants Ensure unrestricted airflow
6.6104.1e Intake fitting	Intake fitting will have an integrated collar at least the same diameter as the duct Fitting will be appropriate for regional weather conditions and installation location on exterior of building	Effectively draw the required volume of air from outside Preserve integrity of the building envelope Envelope The separation between the interior and exterior environments of a building that includes a combination of air and thermal barrier Ensure durable installation
6.6104.1f Weatherproofing	Exterior termination fitting will be flashed or weather sealed Water will be directed away from penetration Weatherproofing will be in accordance with manufacturer specifications	Prevent entry of weather into building shell
6.6104.1g Pest exclusion	Screen material no less than 1/4" and no greater than 1/2" hole size in any direction will be used	Prevent entry of pests into building shell
6.6104.1h Damper (if applicable)	Damper will close when system is off Damper will be installed to open in the direction of the desired flow	Ensure unrestricted air flow Prevent unintended airflow
6.6104.1i Wiring	Wiring will be installed by a licensed contractor Wiring will be installed in accordance with original equipment manufacturer (OEM) specifications, and local and national electrical and mechanical codes Refer to NFPA NFPA National Fire Protection Association, www.nfpa.org 70: National Electrical Code for installation requirements.	Prevent an electrical hazard
6.6104.1j Access	Fan, service switch Service switch An electrical switch that controls the complete flow of electricity to a mechanical device , filter, and conditioning coils will be accessible for cleaning, maintenance, and repair	Allow for maintenance or replacement
6.6104.1k Outdoor/fresh air makeup air handling unit mounting	Air handling unit outlet will be oriented toward the final termination location Air handling unit will be oriented so the equivalent length of the duct run is as short as possible Air handling unit will be mounted securely in accordance with manufacturer specifications and local code requirements (in terms of seismic restraints) Air handling unit will be isolated from the building framing unless specifically designed to be directly attached	Ensure short duct runs to achieve optimum air flows Ensure mounting is installed securely Ensure air handling unit housing or building framing does not shake, rattle, or hum when operating Minimize noise
6.6104.1l Air handling unit/duct riser connection	Duct will be sealed to the top of the curb (for roof-mounted systems) Ductwork will be attached via a flexible connection, and will be installed in accordance with OEM and duct design minimum sizing requirements	Provide the most efficient air transfer from outdoor air to supply termination Prevent noise and vibration
6.6104.1m Duct connections	All ducts, including intake fitting, will be connected and sealed in accordance with supply duct sealing	Deliver outdoor air to desired locations
6.6104.1n Insulation	All components outside of the thermal envelope Envelope The separation between the interior and exterior environments of a building that includes a combination of air and thermal barrier will be insulated to a minimum of R-8 or equivalent to local codes All exposed ductwork outside of the building will be insulated to a minimum R-12, protected from weather exposure, and sealed at all penetrations into building shell	Preserve integrity of the duct system Prevent heat and energy loss Prevent condensation in ductwork
6.6104.1o Register boot to interior surface seal	Register boot will be sealed to interior surfaces with sealants compatible to their intended surfaces Sealants will be continuous and meet fire barrier specifications	Prevent air leakage around boot Ensure a permanent seal to the building air barrier Air barrier The separation between the interior and exterior environments of a building that slows air flow to the point that no smoke movement is visible at 50 pascals of pressure difference across the boundary Prevent a fire hazard
6.6104.1p Preventing air leakage caused by air pressure differences between spaces	Walls, ceilings, and floors will be sealed to separate any occupied space from any unconditioned spaces and adjacent dwelling units Refer to ASHRAE ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers, www.ashrae.org 62.2 Addendum J If system design calls for supply air to enter dwelling units from pressurized corridor to under the door, then door will not be weatherstripped	Ensure occupant health and safety Prevent unintentional air leakage into the building and dwelling units from other spaces (e.g., adjacent dwelling units, garages, unconditioned crawl spaces, unconditioned attics)
6.6104.1q Balance and flow	Air flows will be measured and adjusted in accordance with ANSI ANSI American National Standards Institute, www.ansi.org / ACCA ACCA Air Conditioning Contractors of America, www.acca.org Standard 5 or ANSI ANSI American National Standards Institute, www.ansi.org / ASHRAE ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers, www.ashrae.org Standard 111 and documented to meet design requirements	Achieve the desired air flows to and from the desired locations
6.6104.1r Fire dampers	Fire dampers must be accessible for inspection and/or testing by the local authorities; if fire dampers are not accessible from a grill or register, an access door in the ductwork is required Sealing activities will not interfere with the operation of fire dampers, balancing dampers, or backdraft dampers Type B fire dampers will be used as required by fire code	Ensure access to fire dampers for safe operation Minimize static pressure Maximize air flow
6.6104.1s Occupant/property manager education	Intake fitting will be labeled "ventilation air intake" Occupant/property manager will be instructed on purpose and value of system, and instructed to keep underside of door unobstructed (in pressurized corridor designs) Property manager will be instructed on the maintenance and procedures of maintaining system	Ensure unrestricted air flow Ensure the durability of the ventilation system