I recently had a bathroom ceiling fan installed but I can't tell if it is working properly. After showering the mirror, windows and walls have condensation. Is there a way to test the fan to see if it is working properly?

Turn the fan on, then get up on a chair or ladder and hold a piece of toilet paper up near the fan, and see if the paper is sucked upward against the grill. A bathroom fan generally can't prevent all condensation, but it should cut down on it and you should notice an improvement in the amount of "steaminess" in the room after your shower.

I've had very good luck installing a 15 minute DELAY-ON-BREAK timer on the fan This causes the exhaust an to run for 15 minutes after it's shut off. It has dramatically cut back on condensation.

Another, low tech method that was used in the bathroom was to lower the ceiling above the tub/shower area. There is now less of a chimney that will move the steam into the room.

Nutone/Broan make a VERY Quiet Bath Fan(.3 Sones), with humidity sensor, fully automatic, or manual operation.

THe fan may be working, but not efficiently. The CFM (amount of air moved) of the fan has to be sized to the bathroom-other factors include the type of vent pipe-solid or flex- length of vent pipe, and number of bends.

This site has some good info-click on bathroom fan sizing link EFI's Consumer Division Residential Catalogue | Bathroom Exhaust Fans (http://www.energyfederation.org/consumer/default.php/cPath/30_85)

THe general rule is to determine the proper fan size, then move to the next size up to insure adequate ventilation. THe fan should run for a minimum of 15 minutes after shower use to insure removal of steam/moisture.