Lifebreath 200ERVD - Manual (Page 18)

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SUPPLY AIR DUCTING
In homes without a forced air furnace (see Fig. 7), fresh air should
be supplied to all bedrooms and living areas, excluding bath-
rooms, kitchen and utility areas. It should be supplied from high
wall or ceiling locations. Grilles that diffuse the air comfortably
such as the TECHGRILLE (Fig.5) 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.
In homes with a forced air furnace, you may want to connect the
ERV to the furnace ductwork (see information below).
Direct Connection to Furnace Ductwork
Should you wish to hard duct the supply air directly into the cold
air return of the furnace (see Figures 7, 8, 9), remember to check
the air flow balance of the ERV with the furnace fan both "ON" and
"OFF" to determine that it does not imbalance the unit more than
10%. Also, it is advisable to include a short length of fabric flex
duct or other non-metallic connector in this hard ducted line in
order to keep the ERV separately grounded (electrically) from the
furnace. This will avoid a possible shock hazard to Service People
if a short to ground develops in one of the devices.
Indirect Connection to Ductwork
If permitted by local codes, an indirect connection may be made
between the ERV supply duct and the return plenum of the HVAC
system. The fresh air from the unit may be directed at a grille
installed in the cold air return duct of the HVAC system. The fresh
air supply outlet from the unit should be no closer than 4 inches
(100 mm) and no more than 12 inches (300 mm) from the grille.
CAUTION: An indirect connection to the return plenum is often
prohibited by code. An opening in the return plenum within the
same space as the furnace itself, or a water heater, may create
sufficient negative pressure in the mechanical room to cause
spillage of combustion gases, which can then be drawn into the
return ducting and circulated throughout the dwelling. This method
should be used only in cases where the furnace and water heater
are directly vented appliances with 100% outside air for combus-
tion supplied directly to the equipment.
Stale Air Exhaust System
The stale air exhaust system is used to draw air from the points in
the house where the worst air quality problems occur. It is recom-
mended that return air ducts are installed in the bathroom, kitchen,
and laundry room. Additional return air ducts from strategic loca-
tions (i.e. greenhouse, atrium, swimming pool, sauna, etc.) may be
installed.
An alternative method with low installation cost is to connect the
ERV exhaust duct to the return duct of the HVAC system (see
Fig. 9). In this method, the exhaust air is not ducted back to the
ERV with "dedicated lines" from bathrooms, kitchens etc.
Instead the exhaust air is drawn out of the cold air return of the
forced air furnace. This method has become popular and pro-
vides good ventilation when installed in accordance with the
instructions. The furnace blower must be running when the
unit is operating for this system to be effective.
Dampers and Grilles
The use of balancing dampers and/or adjustable grilles to bal-
ance the flow rates into various rooms is recommended. We
suggest TECHGRILLE air diffusers available from NUTECH
(see Fig.5).
• The TECHGRILLE is a round, fully adjustable grille, which
provides superior, quiet air distribution.
• Available in 4", 5", 6" and 8" diam.(100,125,150 and 200 mm).
We recommend the use of high mounted wall returns with
grilles. The exhaust air duct from the kitchen should never
be connected to a range hood. Instead, the exhaust grille
should be mounted high on the wall at least 4 feet (1.2 m)
horizontally away from the stove. A "flip-up", 6" X 10" (150 X
250 mm) rectangular kitchen grille with removable grease
filter is available. (Grille: Part No. 10-002. Replacement
filter:Part No. 10-002-2).
Removable
filter
Dampers should be located just prior to the Energy
Recovery Ventilator to balance the stale air exhausted
out of the house with a fresh air supply entering the
house. See "Air Flow Balancing".
AIR FLOW
SUPPLY
AIR FLOW
EXHAUST
Figure 5: TECHGRILLE AIR DIFFUSERS