12
Defrost Cycles Tables
Table 5 – HRVXXLHB1150
OUTSIDE TEMPERATURE
DEFROST CYCLES (MINUTES)
EXTENDED DEFROST CYCLES
Celsius (
_
C)
Fahrenheit (
_
F)
Defrosting
Operation Time
Between Each
Defrost Cycles
Defrosting
Operation Time
Between Each
Defrost Cycles
- 5
23
7
50
10
30
- 15
5
7
25
10
20
- 27
- 17
10
20
10
15
Table 6 – HRVXXLHB1250
OUTSIDE TEMPERATURE
DEFROST CYCLES (MINUTES)
EXTENDED DEFROST CYCLES
Celsius (
_
C)
Fahrenheit (
_
F)
Defrosting
Operation Time
Between Each
Defrost Cycles
Defrosting
Operation Time
Between Each
Defrost Cycles
- 5
23
6
50
10
30
- 15
5
6
25
10
20
- 27
- 17
10
20
10
15
AIRFLOW BALANCING
What You Need to Balance the Unit
S
A magnehelic gauge capable of measuring 0 to 0.5 inch of water
(0 to 125 Pa) and 2 plastic tubes.
S
The balancing chart of the unit.
Preliminary Stage to Balance the Unit
S
Seal all the unit ductwork with tape. Close all windows and doors.
S
Turn off all exhaust devices such as range hood, dryer and
bathroom fans.
S
Make sure the integrated balancing dampers are fully open.
S
Make sure all filters are clean (if it is not the first time the unit is
balanced).
Balancing Procedure
1. Set the unit to high speed.
Make sure that the furnace/air handler blower is ON if the
installation is in any way connected to the ductwork of the
cold air return. If not, leave furnace/air handler blower OFF.
If the outside temperature is below 0
_
C/32
_
F, make sure the
unit is not running in defrost while balancing. (By waiting
10 minutes after plugging the unit in, you are assured that
the unit is not in a defrost cycle.)
2. Place the magnehelic gauge on a level surface and adjust it
to zero.
A11217
Fig. 30 - Magnehelic Gauge
A12307
Fig. 31 - Open Balancing Damper
3. Connect tubing from gauge to EXHAUST air flow pressure
taps (see diagram at right). Be sure to connect the tubes to
their appropriate high/low fittings. If the gauge drops below
zero, reverse the tubing connections.
NOTE:
It is suggested to start with the exhaust air flow
reading because the exhaust has typically more restriction
than the fresh air, especially in cases of fully ducted installa-
tions or source point ventilation.
Place the magnehelic gauge upright and level. Record equi-
valent AIR FLOW of the reading according to the balancing
chart.
4. Move tubing to FRESH air flow pressure taps (see dia-
gram). Adjust the fresh air balancing damper until the
FRESH air flow is approximately the same as the EX-
HAUST air flow. If FRESH air flow is less than EXHAUST
air flow, then go back and adjust the exhaust balancing
damper to equal the FRESH air flow.
5. Secure both dampers in place with a fastening screw.
6. Write the required air flow information on a label and stick
it near the unit for future reference (date, maximum speed
air flows, your name, phone number and business address).
7. Install 4 pressure taps plugs (included in parts bag).
NOTES
:
1. Use conversion chart provided with the unit to convert mag-
nehelic gauge readings to equivalent cfm values.
2. The unit is considered balanced even if there is a difference
of
10 cfm (or
5 l/s or 17 m
3
/h) between the two air flows.
E
XHAUST
AIR
FLOW
F
RESH
AIR
FLOW
A12305
Fig. 32 - Balancing Procedure
