Is is cheaper to turn the Air Conditioning off when I leave or keep it on?

Question

My roomate thinks it's cheaper to leave it on when we leave and put it on 75, but then we are cooling the apartment when nobody is there, and that is pointless and wasting money!

I need some evidence from the net that proves my opinions and am asking you to help me!

She's a moron, so it doesn't have to be a from a reputable site. Anything will help!!

Thanks!

Answer 1

I don't know if this will help you, but I was told when I installed my airconditioner to turn it off if I was going to be a way for more than a couple hours. It costs less to recool a room than it does to keep it cool for 8 hours.

Answer 2

It often is but it depends on how long you are gone and how good the insulation is.  You will save some money by doing so but what makes the biggest difference is good insulation and shading outside your home.  A few well-placed trees on the south side of your house could cut your power consumption in half.

Answer 3

No way.  It's only cheaper to leave a heater on all day if it's cold.  With the A/C you need to turn it off.  I had an electrician from the county do an energy audit on our house to prove this to my roommates.  Definitely turn it off.

Answer 4

If you are a GW believer then you should not be using any A/C at all, in fact driving is out of bounds too.

Answer 5

I have heard both ways.  If you turn the air off.....your apartment heats up and it will take the air running on high to cool the place down to where you are comfortable.  If you leave the air on, even turning the temp higher, you are air conditioning an empty apartment.  I have done both and find that my electric bills did not really vary much either way.  I leave the air on while we are not home, I just turn it warmer and then turn it cooler while in the house.  Nothing is nicer than coming home after a hot day at work to a cool house!

Answer 6

depends on how long your gone for, more than 30 minutes and i would say cut it off

Answer 7

just turn it down when you leave so it wont be completely hot when you get home and then cut it back down to where you are comfortable

Answer 8

Energy gain in your apartment is what your AC is removing. You minimize energy gain by letting your apartment drift up and become the hottest  spot north of Havana.

Now, in terms of having comfort when you get back, you would accomplish that by taking your temperature down to 80 before you get home.

If your utility charges extra for daytime electricity, it would make sense to have a tank of very cold water, cooled during the night low price period, to be used to quick cool the apartment when you get home.

Making sure that windows are blinded or shuttered so they do not take in heat is always going to save electricity.

Answer 9

It is cheaper to turn it up to about 80 (depending on where you live) when you leave instead of turning it off.  My Dad was owned an AC Repair Business my whole life and that's what he always told me.  I think it's also better for the AC unit too.

Answer 10

If you are gone for a short time then it is cheaper to keep it at its current temperture setting, that way it will not have to re-cool off the room. When it is turned on it will blast very cold air for a long time to adjust the initial temperture.

If you are gone for a significant time period (say you were gone for a few hours or the period you were gone to work) it would be cheaper to turn it off and cool it off when you return as it would have been running all day. It also helps to keep unnessecary rooms doors shut (do you really need your bathroom air conditioned?)

However both waste energy and are not good options. Mass amounts of air conditioners using electricity are the main cause for power shortages and outages in large cities. Cost aside, for the same use of electricity for 1 air conditioning unit you could run 5 fans.