1. D
2. C
. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
2.1 I
2.2 O
2.3 O
2.3.2 60-M
2.3.3 D
3. M
3.1 Q
4. T
1. D
EFROSTING
When the outside temperature is below 23°F (-5°C), recovery of heat in HRV unit
creates frost in the core. For ERV unit, when the outside temperature is below
14°F (-10°C), recovery of energy creates frost in the core.
To maintain its proper operation, the unit is programmed to defrost the recovery
core. The defrost frequency varies according to the outside temperature.
During the defrost cycle, the unit shifts to maximum speed and the dampers close.
After defrosting, the unit returns to the operating mode selected by the user.
T
ABLE OF
. . . . . . . . . . . . . . . . . . . . . . . 3
C
. . . . . . . . . . . . . . . . . . . . . . . . 4
M
C
A
C
UXILIARY
L
P
C
T
INUTE
RANK
IMER
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
. . . . . . . . . . . . . . . . . . . . . . . . . .7-9
M
. . . . . . . . . . . . . . . . . . . . . . . 7
. . . . . . . . . . . . . . . . . . . . . . . 8-9
. . . . . . . . . . . . . . . . . . . . . . . 9-10
M
ODE
C
ONTENTS
VT4W . . . . . . . . . . . . . . . . . . . 5
. . . . . . . . . . . . . . . . . . . . 6
B
. . . . . . . . . . . . . . . . . . . 6
. . . . . . . . . . . . . . . . . . . . . . . 6
3