Fantech SHR 14105R Installation manual - page 9
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INSTALLING DUCTS GOING TO / FROM OUTSIDE
INSTALLING THE DUCTING TO THE WEATHERHOODS
OUTSIDE WEATHERHOODS
–
The weatherhoods must have built-in "bird" screens with 6.35 mm (1/4 inch) minimum mesh to
prevent birds and rodents from entering into the ductwork. Do not use smaller mesh as it will be very susceptible to plugging up.
The preferred location of the weatherhoods is:
• No less than 3 m (10 ft.) apart from each other.
• At least 457.2 mm (18 inches) snow line or ground level.
• Supply hood must be kept away from sources of contaminant, such as automobile exhaust fumes, gas meters, garbage
cans, containers, cooling towers, tar roofs, etc.
• Avoid prevailing winds, whenever reasonably possible.
The outside perimeter of the weatherhood must be sealed to prevent leakage into the building.
DUCTING FROM THE WEATHERHOODS–TO AND FROM THE HRV
– Galvanized sheet metal ducting with sufficient cross sec-
tion with an integral single piece of insulated wrap with vapor barrier should be used to connect the HRV to the weatherhoods. The
R-value of the insulation should be adequate for condensation control. Insulated flex duct may be used in moderation, if sized and
installed properly. (Consult local codes)
All ducts should be sealed using a good bead of high quality caulking (preferably acoustical sealant) and a high quality aluminum foil
tape, or other approved duct sealant.
Exhaust Air ducting
The stale air exhaust system is used to draw air from the points in the building where the worst air quality problems occur. ( See
installation examples in the manual.)
INSTALLING DUCTS TO / FROM INSIDE
Direct Connection to Furnace/ Air handler return duct
• Should you wish to hard duct the supply air directly into the cold air return of the HVAC systems, remember to check the airflow bal-
ance of the HRV with the HVAC systems fan both “on”and “off” to determine that it does not imbalance the HRV more than 10%.
Make sure you respect the minimum distance from the supply air in of the HRV and the HVAC systems.
• It may be necessary to install a separate fresh air supply ductwork system if the heating is other than forced air.
When installing an HRV, the designer and installer should be aware of local codes that may require smoke detectors and/or
firestats in the HVAC or HRV ductwork.
Because an HRV is designed to bring fresh air into the building, structures may require supply voltage interrupt when smoke or
flame sensors are triggered, or when a central fire alarm system is activated.
To maximize airflow in the ductwork system, all ducts should be kept short and have as few bends or elbows as possible. Forty-
five degree are preferred to 90˚ elbows. Use “Y” tees instead of 90˚ elbows whenever possible.
All duct joints must be fastened with screws or duct sealant and wrapped with a quality duct tape to prevent leakage. Aluminum
foil duct tape is recommended.
SUPPLY AIR DUCTING
In buildings without a forced air HVAC systems, fresh air should be supplied to all habitable areas. It should be supplied from
high wall or ceiling locations. The grilles that are to be used should be designed to properly and comfortably sweep cold surfaces.
Optional inline duct heaters may be used to add heat if required. Typically the reheat is best done using a coil off the same boiler that
heats the pool water.