APPENDICES
Symptom
Cause
Solution
Humidity
levels are
too high;
condensation
appears on
windows
Dehumidistat is set too high.
Set dehumidistat lower.
Undersized ventilator to handle hot tub, indoor
•
pool, etc.
Cover pools and hot tubs when not in use.
•
Lifestyle of occupants.
•
Avoid hanging clothes to dry, storing wood and
•
venting clothes dryer inside. Consider moving
wood outside.
Moisture coming into home from crawl space
•
not vented or heated.
Vent crawl space and place vapor barrier on
•
floor of crawl space.
Moisture is remaining in bathroom and kitchen
•
areas.
Size bathroom ducts to remove moist air as
•
effectively as possible; use bathroom fan to
remove additional moisture.
Condensation is forming in spring and fall.
•
On humid days, as seasons change,
•
condensation appears but air quality remains
high with some ventilator use. Use a control that
provides ventilation in all seasons.
Ventilator speed is set too low.
•
Increase speed of ventilator.
•
Ventilator airflow can be incorrectly balanced.
•
Have a contractor balance ventilator airflow.
•
Humidity
levels too low
Dehumidistat control set too low.
•
Set dehumidistat higher.
•
Blower speed of ventilator is too high.
•
Decrease ventilator blower speed.
•
Lifestyle of occupants.
•
Increase humidity with humidifiers.
•
Ventilator airflow can be incorrectly balanced.
•
Have a contractor balance ventilator airflow.
•
Ventilator and/
or ducts have
frost buildup
Ventilator airflow is incorrectly balanced.
•
NOTE: Minimal frost build-up is expected on
•
cores before unit initiates defrost cycle functions.
Have HVAC contractor balance ventilator.
•
Malfunction of ventilator defrost system.
•
Have HVAC contractor check defrost system.
•
Condensation
or ice buildup
in insulated
duct to
outside
Incomplete vapor barrier around insulated duct.
•
Tape and seal all joints.
•
Tape any hole or tears made in outer duct
•
covering.
Hole or tear in outer duct covering.
•
Ensure vapor barrier is completely sealed.
•
Water in
ventilator
bottom
Drain pans are plugged.
•
Improper connection of ventilator drain lines.
•
Ensure O-ring on drain nozzle adjusted correctly.
•
Look for kinks in line.
•
Ventilator is not level.
•
Level ventilator.
•
Drain lines are obstructed.
•
Check water drain connections.
•
Ventilator heat exchange not correctly installed.
•
Make sure water drains correctly from pan.
•
HR150, 200; ER150, 200 Perfect Window™ Fresh Air Ventilation Systems 68-0171—12
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