Residential HRV/ERV
40
Supply air feels
cold
•
Outdoor temperature
is extremely cold.
•
Supply grille is located
close to occupants
•
HRV automatic defrost
function is not working
•
Locate the supply grilles
high on the walls, or in the
ceiling with a diffuser.
•
Reduce the operating speed
of the HRV
•
Install a small duct heater
(1 kW) behind the supply
grille.
•
If supply air is ducted
through the furnace
plenum, ensure that the
HRV and furnace fan are
interlocked.
Wall
Dehumidistat is
not working
•
The wall control is not
set properly
•
Outdoor RH is higher
than the control
setpoint
•
Bad low voltage
connection or
interruption (due to
a nail in the wall, for
example).
•
For control 611224, ensure
that knob is turned to a
lower setpoint than outdoor
RH.
•
For control 611242-FC,
ensure that the AUTO
mode is selected and the
target RH level is below the
outdoor RH.
•
For control 611227, ensure
the wall control is not
OFF and that the target
RH setpoint is below the
outdoor RH.
•
Check wiring from HRV to
wall control for open/short
circuit.
Indoor air is
too dry (note:
an HRV is not a
dehumidifier,
however by
exchanging
indoor air with
outdoor air,
it can reduce
excess indoor
humidity if the
outdoor air is
drier).
•
Dehumidistat wall
control is set too low
•
HRV operating speed is
too high
•
Improperly balanced
HRV
•
Increase setpoint of
dehumidistat.
•
Operate HRV at low speed.
•
Call a contractor to balance
the HRV airflows
•
Add moisture to air with a
humidifier
