Page 37
Healthy Climate
®
HRV/ERV Ventilators
Sequence of Operation (continued)
NO
YES
Defrost mode
enabled
Complete Defrost
mode. Refer to
defrost operation
logic for schedule
HRV/ERV
unit set to standby
mode
Recirculation mode
(see note 3) is
overridden to
ventilation mode to
execute the humidity
disable feature.
(Damper in ventilation
for 3 minutes once
every 6 hours.) Fan
continues in current
speed.
NO
Fan will run in low
speed ventilation for
3 minutes once
every 6 hours.
Humidity
override not
disabled
YES
Outdoor humidity sampling
automatically runs HRV/ERV fan
in LOW speed ventilation for 3
minutes every 6 hours. This
commences and resets upon
power up of HRV/ERV.
3
4
YES
NO
Is
external
control operating
HRV/ERV fan at
HIGH speed
YES
Humidity sampling
may execute
during HIGH
speed override or
extend HIGH
speed override up
to an additional 3
minutes.
NO
Fan continues to run
in LOW speed for 3
minutes once every
6 hours.
Four
consecutive
temperature readings
60ºF (15ºC) and
above
YES
NO
Humidity override
to high speed is
disabled
YES
NO
Humidity override
to high speed
enabled
NOTES:
1)
Humidity disable is an automatic
operation which cannot be overridden by
any control.
2)
When Defrost mode is enabled (HRV),
the damper is in recirculation mode
(damper closed to outdoor air).
3)
Recirculation mode is only available on
recirculating defrost models (HRV3−095,
HRV3−150−TPD, HRV4−150, HRV4−200).
Dehumidistat Disable
Four
consecutive
temperature readings
below 60ºF
(15ºC)
operation
verified
issue detected;
action required
KEY
HRV/ERV
unit set to recirculation
mode (see note 3)
No external control can
override this mode speed
until cycle is complete,
unless HRV is already in a
recirculation mode.
YES
NO
Is R2000
DIP switch in ON
position
Defrost mode is initiated from 27ºF (−3ºC)
and below. Damper in recirculation mode
at fan speed 4 for 3 minutes, then damper
remains in recirculation mode* fan speed
0 for 25 minutes.
NO
YES
Damper in recirculation mode*, fan
speed 4 for 3 minutes, then
damper in ventilation mode, fan
speed is default for 25 minutes.
YES
Defrost mode
complete
?
Fan speed, damper
position, default to
previous mode prior to
commencement of
Defrost mode.
4
Defrost Mode (HRV)
Thermistor
measures outdoor
temperature
BELOW
27ºF (−3ºC)
Damper in recirculation mode*, fan
speed 4 for 4.5 minutes, then
damper in ventilation mode, fan
speed is default for 17 minutes.
Damper in recirculation mode*, fan
speed 4 for 7 minutes, then
damper in ventilation mode, fan
speed is default for 15 minutes.
BELOW
−4ºF (−20ºC)
BELOW
−31ºF (−35ºC)
YES
YES
NO
NO
NO
operation
verified
issue detected;
action required
KEY
* Recirculation mode is only available on
recirculating defrost models (HRV3−095,
HRV3−150−TPD, HRV4−150, HRV4−200).