should fan on a/c run all the time? - http://www.hvacmechanic.com/ Forums

Original message

summertime

24.255.227.84

"should fan on a/c run all the time?" , posted Sun 22 Jun 13:37

which is better to let fan run 24/7 or put on auto? Engery wise how much elec. does it use. Does it cut down elec bill by keeping air circulating? We have a tappan 12 seer unit, installed in july of 2002. Thanks for all your guidance.

Replies:

ampulman

68.84.236.8

"Re(1):should fan on a/c run all the time?" , posted Mon 23 Jun 14:07

If you are in a high-humidity area, running a constant fan in air conditioning, may decrease dehumidification, which will cause you to set your thermostat lower ($$$$$).

AM

yuri

142.161.109.187

"Re(1):should fan on a/c run all the time?" , posted Sun 22 Jun 14:42:

It depends on whether running it all the time solves a problem, increases comfort level in your home. With 2 story and multiple level homes it sometimes helps equalize the temperatures in the house so one room is not hotter/cooler than the rest. It is not cheap to run. The average direct drive motor uses about 360 watts (3 100 watt light bulbs plus a 60w) 24 hrs a day. 1000watts= 1 kilowatt. I pay 9c/kwhour but some people pay double/triple that. 1000w/360 = 1/3 kwatt x 9c/kwh x 24 hrs/day = 3c/hr x 24 hrs = 72c/day x 30 days = $21.60 month x 12 = $260/yr. Plus it wears out your motor/shortens it life. The new furnaces have ECM motors which use 80 watts on low speed, a big difference. Try it both ways and see if you notice a difference. Better insulation, low E argon windows, good door gaskets, awnings, shade trees make a big difference. Paddle type circulating overhead fans (like in Casablanca) make a big difference if you have vaulted/open ceilings. Can move air down or up. Check with your electric co. for your cost per kilowatt hour and do the numbers.

Yuri

[this message was edited by yuri on Sun 22 Jun 14:48]