Table of Contents
Advertisement
See Table 2 for troubleshooting.
PROBLEM
Air is Too Dry
Air is Too Humid
Air is Too Dry
Persistent Condensation
on Window
Poor Airflow
Supply Air Feels Cold
ERV and/or Ducts Frosting Up
Condensation or Ice Build-Up in Insulated Duct
to the Outside
LEGEND
HRV
— Heat Recovery Ventilator
HVAC — Heating, Ventilation and Air Conditioning
TROUBLESHOOTING
Table 2 — Troubleshooting
CAUSE
Dehumidistat control is set too low.
HRV out of balance.
Dehumidistat control is set too high.
Sudden change in temperature.
Storing too much wood for heating.
Dryer vent exhaust is inside home.
Poor air circulation near windows.
HRV out of balance.
Basement door is closed.
Dehumidistat control set too low.
HRV out of balance.
Improper adjustment of dehumidistat control.
HRV out of balance.
1
/
-in. mesh on the outside hoods is plugged.
4
Filters plugged.
Core obstructed.
House grilles closed or blocked.
Dampers are closed if installed.
Poor power supply at site.
Ductwork is restricting HRV operation.
Improper speed control setting.
HRV airflow improperly balanced.
Poor location of supply grilles. Airflow may
irritate the occupant.
Outdoor temperature extremely cold.
HRV air flows are improperly balanced.
Malfunction of the HRV defrost system.
Incomplete vapor barrier around insulated
duct.
Hole or tear in outer duct covering.
12
SOLUTION
Increase the desired level of humidity. Change
ventilation mode from continuous mode to
standby.
Balance HRV.
Reduce the desired level of humidity. Use
continuous exchange mode.
Wait until outside temperature stabilizes
(winter). Heating will also improve humidity of
air.
Store majority of wood outside. Even dried, a
cord of wood contains more than 20 gallons of
water.
Arrange outside vent for dryer.
Open curtains or blinds. Bay or bow windows
may require additional air circulation.
Balance HRV.
Open the door or install a grille on the door.
Increase the desired level of humidity. Change
ventilation mode from continuous to standby.
Balance HRV.
Reduce the desired level of humidity. Use con-
tinuous exchange mode.
Balance HRV.
Clean exterior hoods or vents.
Remove and clean filter.
Remove and clean core.
Check and open grilles.
Check and open dampers.
Have electrician check supply voltage at
house.
Check duct installation.
Increase the speed of the HRV.
Have contractor balance HRV.
Locate the grilles high on the walls or under the
baseboards. Install ceiling mounted diffuser or
grilles so as not to directly vent the supply air
on the occupant.
Turn down the HRV supply speed.
A small duct heater (1 kW) can be used to
temper the supply air.
Placement of furniture or closed doors is
restricting the movement of air in the home.
If supply air is ducted into furnace return, the
furnace fan may need to run continuously to
distribute ventilation air comfortably.
Minimal frost build-up is expected on cores
before unit initiates defrost cycle functions.
Balance airflow if needed.
Have HVAC contractor check the HRV.
Tape and seal all joints. Ensure that the vapor
barrier is completely sealed.
Tape any holes or tears made in the outer duct
covering. Ensure that the vapor barrier is com-
pletely sealed.
Advertisement
Table of Contents
