3
A12454
Fig. 4 -- Exhaust Ventilation
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
Do not install return--air registers (or stale--air pickup
registers) in same room as gas furnace or water heater.
!
WARNING
Fresh--air registers are normally located in bedrooms, dining room,
living room, and basement. It is recommended that registers be
placed 6 to 12 in. (152 to 305 mm) from the ceiling on an interior
wall and airflow directed toward ceiling. If registers are floor
installed, airflow should be directed toward the wall.
Return--air (or stale--air pickup registers) are normally located to
draw from kitchen, bathroom, basement, or other rooms where
stale--air can exist.
Proper size and type of registers must be used to minimize pressure
drop. The velocity of airflow through register should not be above
400 ft/minute.
Maximum length of duct for the system should be designed
according to the highest speed of the unit. Refer to specifications
listed in unit Product Data for ventilation capacities.
Forced--Air Application
Most HRV applications will be installed in conjunction with new
or existing forced--air system. To operate properly, the fresh--air
supply and stale--air return from HRV connect directly to return--air
duct system. This is how the HRV distributes fresh air and removes
stale air from inside of building (see Fig. 4). For these installations,
furnace or fan coil blower must be interlocked and operate
continuously whenever HRV is energized.
Interlock relay is now integrated into the control and is designed to
interlock HRV with indoor equipment blower. When HRV is
energized, R and G circuit inside of furnace or fan coil will
energize.
NOTE
: The fresh air from HRV is introduced into return--air duct
at a point no less than 10 ft (3m) upstream of furnace or fan coil.
This connection should be direct (see Fig. 4). This is to allow
incoming fresh--air to mix before entering indoor equipment.
Connect Ducts to HRV
PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in minor property
damage from sweating duct or loss of unit efficiency and
capacity.
If HRV duct work is installed in an unconditioned space,
insulated flexible duct is required.
CAUTION
!
Insulated flexible duct is required on both fresh--air inlet and
exhaust--air outlet ducts connecting to exterior wall.
When
using insulated flexible duct, the vapor barrier of the flexible ducts
must be taped very tight to prevent condensation problems. To
reduce pressure drop, stretch the flex duct and support it in a proper
manner to avoid reduced airflow.
When connecting the HRV to a return--air duct system, insulated
flexible duct can be used. However, when metal or rigid ducts are
applied use approximately 18--in. (457 mm) of flexible duct at
HRV ports for fresh--air supply, and stale--air return. When using
metal duct from fresh--air supply to system duct work, the metal
duct should be insulated. This can act as a silencer when
connecting ducts to return--air duct system. This should eliminate
transmission of noise or vibration from unit to main duct system.
NOTE
: Balancing dampers should be installed in stale--air exhaust
and fresh air intake ducts before connecting to the HRVXXLVU
units. Make sure both balancing dampers are left in fully open
position before connecting the ducts to these ports. See Integrated
balancing damper illustration.
Condensate Drain
To connect condensate drain, proceed as follows:
1. Insert sleeved grommets into bottom of unit using the gas-
ket washer and nut (see Fig. 5).
2. Cut two sections of plastic tubing, about 12--in. (305 mm)
long and attach them to each drain.
3. Join the two short sections of plastic tubing to the “T” con-
nector and the main tube as shown.
4. Make a loop in the tubing below the “T” connector to create
a trap to prevent sewer gases from entering the ventilation
system (see Fig. 5).
