I have heard & read it's better to leave your AC on at a high temp setting when your not home, then to turn it off in the morning & turn it back on at night.

I'm out of my house by 7am & don't get home till around 5pm or later. I turn my AC off when I leave. My normal set temp is 72. When I get home I flip it back on. The temp in the house is about 80-82 with the windows open or closed. Makes no difference.
It takes about 5-6 hours to cool the house back down to 72. It's a normal 3 br home nothing huge.
So if I get home at 5pm the house is cooled by 10pm or so.

Starting tomorrow since it's the 1st day of my electric billing period, I'm going to test it. I'm going to leave the AC on at a set temp of 80. Do this all month & see if my bill is higher or lower.

Has anyone actually seen a difference in doing this?

It really makes no sense to me since I can't see leaving the unit on with on one home. Just like leaving lights on.

 

Spend $40 on a programmable tstat. That way it has you set up for your temps so it is higher during the day and begins cooling before you get home so the temp is good before 10pm.

 

I do have 1. Just no clue how to use it.

 

I am told it's a trade off; what you save during the day when it's set real high you lose when it runs continiously to cool things off once you bump it back down.

 

Just do what I do. Get a dog so you leave it on for him/her. Then I don't question if I would save money turning it off

 

ours is programmed to just a couple degrres difference when we are home and away.

i really don't know if it saves us money but i know i never have to touch it

 

A/C is either ON or OFF, no "Max" or "Min" cooling.

So, leaving it off all day and then turning it on in the evening means it'll run continuously for 5+ hours. That 5+ hours is the same then as it would be if it were broken up into 10 30-minute periods throughout the day, to keep the house managebly cool (say 78*F daytime when nobody around, 73*F when someone is around). IMO and in my experience, running a programmable thermostat saves you money, period. My nat. gas AND hydro bills both went down an average of 14% over the past 2.5 years since I got the t-stat, and that's with the addition of a new baby (more clothes to wash = more gas for hot water, and more electricity for all the stuff).

14% is very significant if you think of hydro+gas being about $140/month on average.

 

Everything is electric here, No gas. I'm testing it so I'll see. The TS I have is not installed. I'm renting the house so I rather not spend $ to install it. Have to get some quotes. No way I can handle it since I'm renting I don't want to mess anything up I'll be libel for later. When it's in the 70's in FL my bill has been about $90. In the hot months like now it's been in the $160's.

 

Installing a programmable t-stat is SIMPLE... usually 4-6 wires that come off of labelled posts in the old t-stat, and onto new posts in the new one.

Just have some masking tape, a pen, and a few screwdrivers handy. I installed my programmable t-stat in under 8 minutes last month.

 

Doesn't have air conditioning

 

^^Window shaker?

 

I usually have it set at 72 for sleeping. When I leave for work in the morning I bump it up to 75 since the wife and kid are home during the day. When they are out or away like this week, I set it to 78 when I leave home in the morning.

I saw a difference in my electric bill at my old place when I had them on all day at different settings as opposed to turning them off and on. I went from about $150 in the summer to about $120.

 

wow 72 degrees?

In areas that have high heat the cost savings can be huge just turning it up a few degrees.

78 degrees is considered the best all around temperature to save $$ for efficiency. For Every 1 degree under 78 you turn it down it will cost 10% more on your monthly bill. So the difference from 78 to 75 degrees will be 30% more on your monthly costs!

Turning off the A/C is not worth it during the day as someone said; it will take MANY MANY MANY hours to bring the temps back down. Not to mention it wouldn't be good on your A/C compressor to be running that long without a rest. It'll be a never ending battle if you let the temps rise a lot.


RaviNJCLs

78 to 72 is a huge swing! The most you ever want to do is 3 degrees if your trying to save $$. Just adding a fan into your bedroom will make the wind chill difference up to not need 72 degrees.

And it's very difficult to compare cooling costs; you need to factor in the humidity and actual outside temperatures. So unless you keep excellent records of this data just comparing month to month bills will not tell you anything...


To keep my house at 75 degrees in the 90+ degrees Kansas heat (95 yesterday) and high humidity costs me about $120-140 a month. I am in a 2700 sq/ft house + an unfinished full basement. We have all double pane windows with storm windows over them. I think our A/C unit is a 13 seer.

Don't forget when reading everyones costs there's a ton of factors... how much direct sun exposure they have. What kind of insulation they have. How efficient their A/C unit is. What type of windows are installed. What the square footage is. Is the A/C unit sized correctly for their situation? ... tons of variables.

 

I was thinking the same thing. 72 seems really low.

 

Something else you might to check out if whether your utility company offers balanced payment plans. It makes budgeting a whole lot easier, especially for me since my utility bill can fluctuate from $60 to $130.

 

Siggy....good advice.

Our problem with our place is that the thermostat is on the first floor right above a vent. Even when I close the vent, it stays a lot colder on the first floor than the bedrooms on the second floor. If I set it to 78, the temp is over 80 in the bedroom. I like it cold when sleeping, and if it gets too warm, my son can't sleep either. He takes after me. I tried every temp between 75 and 70, and 72 seemed to be best.

If we weren't renting I would try to move the thermostat, or add a fan, but for now, I'll have to deal with it. I added fans when we lived in Jersey and it was a big difference in the bedrooms.

Also, my wife likes to let in the "light" so all the blinds are wide open when I get home. I finally got her to keep the ones in the bedrooms closed.

All in all though, it's less than we were paying in Jersey because the insulation is a lot better and we don't have cathedral ceilings anymore.

 

+2 (or whatever number I would be) on the programmable TS. You can even take it with you when you move.

We have our temp set higher during the day when we're not home, then have it come on later in the day before we come home. It's also off most of the night. We have 4 programs (Wake, Leave, Return, Sleep) on ours, so it's easy to customize it to get the most efficiency out of it. Our thermostat also has a "recovery" feature, so it the temp starts climbing too quickly or gets too high, it will kick on even though it's programmed to be off. This prevents the A/C units from working too hard when it's time for them to kick on. We also have an open floor plan, so I use the units upstairs to cool the whole house for most of the time they're on. The unit downstairs (our master is down) only runs a couple of hours a day due to this. It took us about one full season to figure out the best way to coordinate everything... but now that we have it it's very efficient. For your reference, our electric bill is about $120-$140/mo in the summer and that's everything (cooling the entire house, all appliances, and our pool running 8 hours per day).

 

You should close all downstairs vents.

 

Adjust the main dampers for upstairs and downstairs. I have the 1st floor mostly shutoff and I the 2nd floor wide open.

On a traditional 2 story:

Damper settings...

Summer:
2nd floor wide open
1st floor 80-90% shut

The cold air will drop down to the 1st floor. Cooling both the 2nd and 1st floors.

Winter:
2nd floor 80-90% shut
1st floor wide open

The hot air will rise and heat both the 1st and 2nd floors.


I also play with the register controls as well. It takes some time to get it just right. But mark your dampener settings on the vents with a dry erase marker. Then once you get it right mark summer/winter on the dampener to make it easier to switch every year.


In case you are wondering... the lever on the damper works just like a plumbing or gas valve. Parallel to the vent it's wide open, 90 degrees off from vent flow it's fully closed. You'll be able to hear the back pressure as you adjust it. Try and never fully close either of them permanently. You don't want to strain your blower motor.

 

Well I got my next bill. It's actually $5 higher, then when I shut the AC off.

So it's about the same for me in price.

 

[QUOTE=juniorbeanWe have our temp set higher during the day when we're not home, then have it come on later in the day before we come home. It's also off most of the night. We have 4 programs (Wake, Leave, Return, Sleep) on ours, so it's easy to customize it to get the most efficiency out of it. Our thermostat also has a "recovery" feature, so it the temp starts climbing too quickly or gets too high, it will kick on even though it's programmed to be off. This prevents the A/C units from working too hard when it's time for them to kick on. We also have an open floor plan, so I use the units upstairs to cool the whole house for most of the time they're on. The unit downstairs (our master is down) only runs a couple of hours a day due to this. It took us about one full season to figure out the best way to coordinate everything... but now that we have it it's very efficient. For your reference, our electric bill is about $120-$140/mo in the summer and that's everything (cooling the entire house, all appliances, and our pool running 8 hours per day).[/QUOTE]


we have only one ac unit but the house is small.
wake is 30 min b/f we get up 73 degrees
leave is about 30 min b/f we leave for work 75 degrees
return is 30 min b/f we get home 73 degrees
sleep is 30 min before we go to sleep 73 degrees

we only changed the temp when we are away in the cooling season, i need it a little cooler at night to sleep.
we also use the ceiling fans when we are home also to circulate the air



winter

wake is 30 min b/f we get up 71
leave is 30 min b/f we leave 69
return is 30 min b/f we get home 71
sleep is 30 min b/f we go to sleep 69



i guess my thought process is, it will at least start to warm up b/f we get up so it's comfortable and turns off 30 min b/f we leave or sleep since the house will still be comfortable until we get under the covers.