Installing Ducts To / From Inside; Airflow Balancing - Fantech SHR450 Manuel D'installation

Installing ducts to / from inside

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 90o elbows. Use "Y" tees instead of 90o 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. Grilles that diffuse the air comfortably such as grille {MGE (metal) } grilles with "coanda effect" are recommended.
Optional inline duct heaters may be used to add heat if required.
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 balance 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.
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.)

Airflow balancing

• The balancing procedure consists of measuring the exhaust air leaving the system and the supply air entering the system and ensuring that these
two are equal. A deviation of 10% or less is acceptable.
*
A
Pitot tube and gauge
A professional air balancer should be contacted to commission the system properly. A skilled HVAC Tech may complete the balance
of air providing they possess the proper equipment. Call Fantech Technical support for assistance.
A The duct's airflow velocity
is generally measured
with a magnehelic gauge
and a pitot tube.
• To avoid airflow turbulence
and incorrect readings, the
airflow velocity should be
measured on steel ducting
a minimum of 3 duct
cross-sections from the
unit or elbow and before
any transition.
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