| 6.6202.2a
Wiring | Wiring will be installed in accordance with original equipment manufacturer specifications, and local and national electrical and mechanical codes | Prevent an electrical hazard |
| 6.6202.2b
Access | Fans,
service switch
Service switch
An electrical switch that controls the complete flow of electricity to a mechanical device
, filters, drain, and drain pan will be accessible for maintenance in accordance with authority having jurisdiction | Maintain designed air flows and system performance Ensure occupant health and safety |
| 6.6202.2c
Fan mounting | Fan will be securely mounted in accordance with manufacturer specifications Fan will be oriented so the equivalent length of the duct run is as short as possible; calculate "equivalent length" in accordance with
ANSI
ANSI
American National Standards Institute, www.ansi.org
/
ACCA
ACCA
Air Conditioning Contractors of America, www.acca.org
Manual D (Residential Duct Systems) Fan will be isolated from the building framing unless specifically designed to be directly attached | Ensure short duct runs achieve optimum air flows Ensure fan is mounted securely Ensure fan housing or building framing does not shake, rattle, or hum when operating Minimize noise |
| 6.6202.2d
Backdraft dampers (required for intermittent operation) | A
backdraft damper
Backdraft damper
A damper that allows air to flow in only one direction
will be installed between the heat recovery ventilator (
HRV
HRV
Heat recovery ventilator
) or energy recovery ventilator (
ERV
ERV
Energy recovery ventilator
) and the exterior, unless the system operates continuously Outdoor air intakes and exhausts will be equipped with automatic or gravity dampers that close when the ventilation system is not operating | Prevent reverse air flow when the system is off |
| 6.6202.2e
Installation of fittings | Collar will be at least the same diameter as the exhaust fan outlet; if collar is larger than exhaust fan outlet, a rigid metal transition will be used Fitting will be appropriate for regional weather conditions and installation location on house so as not to be rendered inoperable | Achieve the desired air flows to and from the designated locations Ensure unrestricted air flow 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
|
| 6.6202.2f
Duct connections | Ducts will be connected to applicable registers or grilles, collector box,
HRV
HRV
Heat recovery ventilator
or
ERV
ERV
Energy recovery ventilator
, intake fitting, and termination fitting Ducts will be connected and sealed as follows: - Metal-to-metal or metal-to-PVC will be fastened with a minimum of three equally spaced screws
- Flexible duct-to-metal or flexible duct-to-PVC will be fastened with tie bands using a
tie band
Tie band
A strap, often made of nylon, that mechanically squeezes a flexible duct to a fitting. Must have a minimum performance temperature rating of 165° (per UL 181A-type test) and a minimum tensile strength rating of 50 pounds
tensioning tool
- Flexible duct between
tie band
Tie band
A strap, often made of nylon, that mechanically squeezes a flexible duct to a fitting. Must have a minimum performance temperature rating of 165° (per UL 181A-type test) and a minimum tensile strength rating of 50 pounds
and end of metal or PVC duct will be screwed into place
- PVC-to-PVC materials will be fastened with approved PVC cement
- Other specialized duct fittings will be fastened in accordance with manufacturer specifications
- In addition to mechanical fasteners, duct connections will be sealed with
UL
UL
Underwriters Laboratories
181B or 181B-M listed material
| Achieve the desired air flows to and from the desired locations Preserve integrity of the duct system and building
envelope
Envelope
The separation between the interior and exterior environments of a building that includes a combination of air and thermal barrier
|
| 6.6202.2g
Duct layout | Air to be exhausted to the outdoors will not be taken directly from the forced air system Supply ducts attached to the return side of forced air systems will be: - Attached as close to the
HVAC
HVAC
Heating, ventilation, and air conditioning
system's fan as possible while remaining in compliance with manufacturer specifications
- Set up to provide filtration of outdoor ventilation air before reaching the
HVAC
HVAC
Heating, ventilation, and air conditioning
system with minimum
MERV
MERV
Minimum efficiency reporting value
6 filter
- Connected to the intake fitting
- Connected and sealed in accordance with the supply duct detail
| Achieve the desired air flows to and from the desired locations Preserve integrity of duct system and house Ensure occupant health and safety |
| 6.6202.2h
Insulation | Ducts installed 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 | Preserve integrity of the duct system by eliminating condensation |
| 6.6202.2i
Sealant selection | Gap between registers or grilles and interior surface will be sealed Sealants will be compatible with their intended surfaces Sealants will be continuous and meet fire barrier specifications | Prevent air leakage around registers or grilles Ensure a permanent seal Prevent a fire hazard |
| 6.6202.2j
Balance and flow | Air flows will be measured and adjusted to match to the system's intent | Achieve the desired air flows to and from the desired locations |
| 6.6202.2k
Occupant education | Occupant will be educated on how and when to change filter and clean drain pan, if applicable, according to manufacturer specifications | Ensure occupant health and safety Preserve integrity of system |
