Does running whole house fan all the time save energy??

Question

My father in law always said if we set our AC fan to "on" instead of "auto" so it would run even if the AC unit was not it would keep the house cooler, make the AC run less, and actually save energy.

Does anyone know of the truth to this? Does it make the AC run less? And if so, is the difference enough to compenstate for the electricy being used to run the fan all the time?

Thanks!

When I say "whole house fan" I am not referring to an attic fan, but the fan that circulates the air that is either heated/cooled in our forced air heating/cooling system. In the "on" position in runs all the time, in the "auto" it runs only when the condenser (or heater) is running.

Answer 1

Running the fan will keep the air moving in your house. This will help you feel cooler because it helps evaorate perspiration.

This will permit you to set your thermostat a little higher and still feel comfortable. The A/C will run less and you will save energy that way.

Running the fan uses much less energy than running the A/C.

Answer 2

Well the basic concept is accurate.....

However, there are several factors which affect this. The AC fan itself may not provide good circulation throughout the entire house and ensure fairly even temperatures throughout. Therefore, you end up with "hot" and "cold" spots. If the thermostat is in a "hot" spot the AC will run much more, and conversely if it is in a "cold" spot.

I have ceiling fans in every room in my house and keep them running on low most all the time.

The way to run them is blowing up in the winter to properly circulate the warmer air, and help keep the heat down in the living space.

During the summer, you change the fan direction to blow down. Again this properly circulates all the air in the house, and helps keep you cool by the motion of the air across your body, just as you would by sitting in front of a fan.

So the accuracy of the AC fan "concept" is accurate. Most houses require more than just the AC fan running to properly circulate all the air in the house. Some central air systems do a very efficient job of it though.

Hope this helps.

Answer 3

Leave the fan off. Your house (and the air inside) will absorb heat from the sun at the same rate whether you have the fan on or not, and the air conditioner will have to do the same amount of work to take the heat out again. Those big AC and furnace fans draw a lot of power, too, since they have to blow air around the whole house quickly.

Instead, consider installing a fan in the attic to blow some of that solar-heated air out before it has a chance to transfer heat through your ceiling. The fan doesn't have to be nearly as powerful (or loud) and your air conditioner won't have to work so hard, so you'll save money in the long run.

Answer 4

First, a "whole house fan" is used to remove the excessive heat build up in attic spaces. It is usually ran during the early evening when the outside air is cooler. The fan forces the hot air out and sucks cool air in through the house. This type of fan does save energy.

What you have is most likely a type of "air handler". Air is blown across cool coils into a duct system that distributes the cool air throughout the house. It does not save money to run that 24/7. In fact you'll use more energy running the motor like that and it'll be more wear-n-tear on the bearings and motor windings.

Answer 5

Yes and no... (very definitive)

it really depends on the climate and the house.

In somce cases all you need is to circulate the air to feel comfortable and you can leave the refrigeration par of the AC off. also circulating the air mixes the cooler air from one part of the house with warmer air from another. If you have a basement and the central heatin/cooling system circulates that air into the rest of the house, it can prevent needing the refrigeration system in some cases.

Answer 6

Not really. The amount of energy you use to cool is primarily a function of the difference in temperature of the inside and outside, and how well your home is insulated and sealed.

Running the fan will make the temperature more even through the house, but probably will not save energy unless the thermostat happens to be located where it warms up the quickest. It may save a little then.

Answer 7

Yes it would make the house cooler,therefore reducing the amount of times the condenser turns on .The fan motor is very small and the amount of energy it uses is minimal. Running in the on position, also the natural airchanges you house needs to be a healthy enviroment!

Answer 8

The answer is yes. When an electric motor starts up it draws a high amp surge until it reaches its operating running speed at which time the amperage drops to its constant operating amp load. Shutting it off and then restarting it causes it to pull a high amp load each time it is restarted. This is causing it to use more electricity than it would if you leave it running all the time unless it's going to be off for a long period. Jut like if you stop your car , if someone is with you, just to run in a store or something, it saves gas to leave it running because it takes more gas to start a car than if you were to let it keep running a short period of time.

Answer 9

No because running that fan will use alot of electricity instead of conserving the temp. that is already inside house and steading that to a comforting level with an AC/Heater that is on auto.

Answer 10

I don't think that's true. If you just run the fan, you aren't getting any cool air at all. To get cool air, you need to have the AC on.