Check out these tips and explanations, below, from our Heating and Cooling Expert. Of course, you're also welcome to post questions to this board for more information: Just click the "Ask about Heating & Air Contidioning" button at the top of the page.

NorthernHeat

Yes, am ais conditioner uses the blower fan in the furnace to circulate the cold air throughout the house. Some air conditioners are hooked up to an air handler, very simular to a furnace, but either has no heat, electric heat banks, or it could be a heat pump.

NorthernHeat

Yes, an air conditioner uses the fan and usually the low voltage controls of the the furnace/air handler to move warm air through the evaporator/cooling coil of your air conditioner.

NorthernHeat

Temperature split should be about 15-18 degrees F, same as an air conditioner split, dependant on how cold it is outside. Supply air temperature minus the return air temperature should be about 15-18 degrees.

NorthernHeat

Manufacturers have used many differant means over the years to defrost heat pumps. It could be based on run time, demand or both. In short, when the heat pump needs to get rid of the frost and ice build up on the condenser coil, it stops the fan, the compressor continues to run and the reversing valve changes the refrigerant direction. During this time, the coil in the outside unit gets hot and melts the frost. Steam is often produced during this defrost cycle.

teamplayer

Thanks to this thread, I solved a simple problem with my Hunter 44110 thermostat. It failed to start the heat cycle, even though the fan switch could turn on the fan. The problem was intermittent contacts between the mounting plate and the brass pins on the thermostat. I think I've solved it with small pieces of aluminum foil wedged in them to prevent them from opening up. Seems like a faulty design problem.