from Laura in Waukesha, WI:
#305
I would like to cut back on my air conditioning usage. My home is well shaded and many days are not hot enough, but would be more comfortable if I were to put on the blower fan from my system. Is this cost efficient or does it use as much electricity as running the air conditioning?
Yes, but the energy savings can vary.
Running the just the blower can save electricity over running the central air conditioning unit. However the amount you save will vary depending on several factors, such as the size and layout of your home, size and efficiency of your air conditioner, what type of blower motor you have, and how long the blower runs. The very short answer is: the longer you run the fan, the less likely you are to see cost savings.
For example, if you run an air conditioner with a single speed fan on "auto" fan mode, you will use about 1,100 kWh, or $132.
If you never turn on the air conditioner and run the same fan continuously for the entire cooling season, you will use about 1,250 kWh, or $150 (about $20 more than the air conditioner on "auto" fan).
If you run the same fan just 25% of the season and never turn on the air conditioner, you will use about 300 kWh, or $36 (about $100 less than running the air conditioner on "auto" fan).
In addition, the type of blower in the furnace will make a difference. A furnace with a variable speed fan motor will use about 1/5 of the energy that a single speed fan motor.
Published Friday, June 26, 2009