Ceiling Fans & HVAC Efficiency

[benjamming]

Do ceiling fans improve or reduce the overall efficiency of HVAC systems? I understand that ceiling fans will add heat to a room from their electric motor & cool due to evaporation on a person's skin. However, do they move enough air through a house to improve HVAC efficiency to make them worthwhile to run even when no one is in the room? Any idea what of % increase or decrease?

 

[oilyriser]

A/c can be set warmer if the air is moving, but I don't think a breeze helps keep you warm in winter. They increase the heat transfer through the walls, by increasing convection, so should be off when nobody is around.

 

[Steve S]

They cause a breeze in the summer so the air seems cooler and in the winter you can reverse the direction of rotation in the winter and it circulates the hot air that stratifies close to the ceiling and the room is warmer . I have ceiling fans in the kitchen ,living room and bedrooms. They work .Buy an energy star rated one.

 

[duaneb9729]

in this case the variables would really impact your results, if you have good windows?, or do they leak?, do you have the proper amount of insulation for your part of the country?. is your duct system properly installed?

all these things would impact how you feel in your home.

this being said, i have ceiling fans in my house. but i havent seen any increase or decrease in my heating or cooling bills

 

[PandaBear]

Ceiling fan does wonder for my otherwise unbearable house in the summer (no AC). You can set the AC warmer when the ceiling fan is on, so in a way save you money.

 

[H2GURU]

Reversing the rotation for winter sounds good, but you can't sit in a room with a breeze in the winter. Only structures with 15 ft. or higher ceilings will get any benefit, such as a chalet or a high ceiling in a garage/warehouse.

 

[benjamming]

Ceiling fans were purchased & installed when the house was built. Windows are good. Insulation is R38-42. Duct work is metal & insulated. The family room has a 15' ceiling.

This was just a discussion my father-in-law & I were having. He believes that you should leave all the ceiling fans on all the time to help circulate the air throughout the house better which will help the HVAC system. I disagreed.

 

[Schmoe]

I'm with you Ben.

 

[msparks]

I leave my Hvac fan on all the time, it seems to help rooms stay a consistent temp throughout the house.

I have small fans in rooms that I'm in all the time. (like the computer room.

Hope this helps.

 

[Al]

Originally Posted By: msparks
I leave my Hvac fan on all the time, it seems to help rooms stay a consistent temp throughout the house.

Its probably a mistake from a $$$/cents point of view. If you have a good filter though it would give better house filtration. You might want to check the amps on the fan unit.

 

[Cory]

Originally Posted By: benjamming
Ceiling fans were purchased & installed when the house was built. Windows are good. Insulation is R38-42. Duct work is metal & insulated. The family room has a 15' ceiling.

This was just a discussion my father-in-law & I were having. He believes that you should leave all the ceiling fans on all the time to help circulate the air throughout the house better which will help the HVAC system. I disagreed.

You were correct. I've done much energy research for our home.
As per Energystar.gov
Turn Off When not in the Room
Ceiling fans cool people, not rooms. If the room is unoccupied, turn off the ceiling fan to save energy.