16
The Three Methods of Installation
The three methods of installation for the HRV system are the
Simplified, Partially Dedicated and Fully Dedicated
Installations. Refer to the installation illustrations in this manual.
Simplified Installations
The Simplified Installation draws stale air from the cold air
return duct of the air handler/furnace and introduces an equal
amount of fresh air farther downstream into the cold air return.
Refer to "The Simplified Installation" in this manual.
The air handler/furnace blower must be running when the unit is
operating for this system to be effective. Refer to "Interlocking
HRV Operation to an Airhandler/Furnace Blower".
Partially Dedicated Installations
The Partially Dedicated Installation draws stale air from specific
points in the house and introduces an equal amount of fresh air
into the cold air return. Refer to "The Partially Dedicated
Installation" in this manual.
Stale air ducts should be installed where the worst air quality
problems occur (bathroom, kitchen, and laundry room). Each
location with a stale air duct should have a timer which will
initiate high speed ventilation. Refer to "Optional Timers" in this
manual.
The air handler/furnace blower should be running when the
HRV is operating to evenly distribute the fresh air throughout
the house. Refer to "Interlocking HRV Operation to an
"Airhandler/Furnace Blower".
Fully Dedicated Installations
The Fully Dedicated Installation draws stale air from specific
points in the house and introduces an equal amount of fresh air
to specific locations of the house. This system is not connected
to an air handler/furnace. Refer to "The Fully Dedicated
Installation" in this manual.
Stale air ducts should be installed where the worst air quality
problems occur (bathroom, kitchen, and laundry room). Each
location with a stale air duct should have a timer which will
initiate high speed ventilation. Refer to "Optional Timers" in this
manual.
Fresh air ducts should be installed to all bedrooms and living
areas, excluding bathrooms, kitchen and utility areas. Grilles
should be located high on a wall or in ceiling locations. Grilles
that diffuse the air comfortably such as the Round Diffuser are
recommended. If the floor is the only option available, then
special care should be taken in locating grilles. Areas such as
under baseboard heaters will help to temper the air. Also,
optional inline duct heaters are available for mounting in the
supply duct work to add heat if required.
Air Duct Design and Installation
A well designed and installed ducting system will allow the
HRV to operate at its maximum efficiency.
Always try to keep duct runs as short and straight as possible.
See Installation Diagrams for various installation options.
The inner and outer liners of the flexible insulated duct must be
clamped to the sleeve of the weatherhoods (as close to the
outside as possible) and the appropriate port on the HRV. It is
very important that the fresh air intake line be given special
attention to make sure it is well sealed. A good bead of high
quality caulking (preferably silicone sealant) will seal the inner
flexible duct to both the HRV port and the weatherhood prior to
clamping with a large zip tie.
To minimize air flow restriction, the flexible insulated duct that
connects the two outside weatherhoods to the HRV should be
stretched tightly and be as short as possible.
Twisting or folding the duct will severely restrict air flow.
Installing the Ducting Between the HRV & Living Areas
in the House
To maximize airflow in the duct system, all ducts should be kept
short and have as few bends or elbows as possible. Forty-five
degree elbows are preferred to 90° elbows. Use “Y” tees instead
of 90° elbows whenever possible.
All duct joints must be fastened with screws, rivets or duct
sealant and wrapped with mastic or a quality duct tape to
prevent leakage. Mastic is preferred but if duct tape is used, we
recommend aluminum foil duct tape.
Galvanized ducting from the HRV to the living areas in the
house is recommended whenever possible, although flexible
duct can be used in moderation if necessary.
To avoid possible noise transfer through the duct system, a short
length (approximately 12 inches or 300mm) of non-metallic
flexible insulated duct should be connected between the HRV
and the supply/exhaust duct system.
The main supply and return lines to/from the HRV must be 6
inches (150mm) minimum. Branch lines to the individual rooms
may be as small as 4 inches (100mm), but 5 inch (125mm) lines
are preferred .
All ducts running through attics and unheated spaces must be
sealed and insulated to code.
Installation Methods
Include a short length of fabric, flex duct or
other non-metallic connector in the “Fresh Air to
Building” hard ducted line in order to keep the
HRV separately grounded (electrically) from the
air handler. This will avoid a possible shock
hazard to service people if a short to ground
develops in one of the devices.
WARNING
Applications such as greenhouses, atriums,
swimming pools, saunas, etc. have unique
ventilation requirements which should be
addressed with an isolated ventilation system.
