| Posted By |
Message |
| Pages: [1] 2 |
cgdg61606
Little Brother Christopher
Member since 2/07 6815 total posts
Name:
Christine
|
Do you keep your CAC running even when you are not at home?
I've heard that you should keep it running because if you shut it off and the house heats up, the CAC has to work harder to cool the whole house again.
My husband refuses to leave it running when we aren't home because he feels it's a waste. But it does take a really long time to cool the house again.
What do you do?
Thanks!
|
Posted 7/8/10 2:56 PM  |
| |
|
Prudential Douglas Elliman Real Estate
Long Island's Largest Bridal Resource | Long Island Weddings |
jam11308
Member since 11/07 7273 total posts
Name:
|
Re: Do you keep your CAC running even when you are not at home?
We leave it on, but set the thermostat to auto-adjust it. It changes to 72 after we leave in the morning, drops down to 70 an hour before dh gets home and then auto-drops to 69 at 10pm.
|
| Posted 7/8/10 3:00 PM |
| |
|
Jenn627
Laaaaaaaambert!
Member since 5/08 9818 total posts
Name:
Jenn
|
Re: Do you keep your CAC running even when you are not at home?
We leave it off. But we gradually turn it down when we get home.
Usually it's 88 degrees in our house when we get home, so we'll turn on all our ceiling fans and drop it down to 87, just so the air kicks on. The house will usually cool itself to about 80 with this method. Then we'll adjust it more.
|
| Posted 7/8/10 3:04 PM |
| |
|
Kristin616
Member since 8/06 3595 total posts
Name:
Kris
|
Re: Do you keep your CAC running even when you are not at home?
We leave it running. If I know we won't be home all day I'll kick it up to 80 then drop it when we get in
|
| Posted 7/8/10 3:06 PM |
| |
|
CrankyPants
I'm cranky
Member since 7/06 18178 total posts
Name:
Mama Cranky
|
Re: Do you keep your CAC running even when you are not at home?
We leave it running, just set a little higher.
I think I read it costs more to try to cool off the house if it has been off all day than to just set it a little higher for when you are gone. But, I could be making that up!
|
| Posted 7/8/10 3:22 PM |
| |
|
cgdg61606
Little Brother Christopher
Member since 2/07 6815 total posts
Name:
Christine
|
Re: Do you keep your CAC running even when you are not at home?
Posted by CrankyPants
We leave it running, just set a little higher.
I think I read it costs more to try to cool off the house if it has been off all day than to just set it a little higher for when you are gone. But, I could be making that up!
That's the same thing I heard!
We don't shut it off completely, but raise it enought that it barely runs if at all and still have several degrees to lower to cool back down when we come home.
|
| Posted 7/8/10 3:25 PM |
| |
|
gforce
My other love!
Member since 5/08 1744 total posts
Name:
|
Re: Do you keep your CAC running even when you are not at home?
We leave it on, our dog is home and for the past few days it would have been really ahrd for him.
|
| Posted 7/8/10 3:44 PM |
| |
|
MaZz
* Lovin my baby girl!!! *
Member since 2/09 6243 total posts
Name:
Gina
|
Re: Do you keep your CAC running even when you are not at home?
Thankfully our condo stays cool... we have tons of shade in the summer... We have it set for about 68 at night and then shut off in the morn... the most it ever got up to in the heat wave so far was 76 in the daytime... so we're lucky it stays relatively cool without having to use any CAC during the day
Message edited 7/8/2010 3:49:09 PM.
|
| Posted 7/8/10 3:48 PM |
| |
|
KittyGags
LIF Adult
Member since 7/09 5614 total posts
Name:
|
Re: Do you keep your CAC running even when you are not at home?
We just kick up the temp a few degrees when we're not home all day and dial it down when we get home.
|
| Posted 7/8/10 4:05 PM |
| |
|
Andrewz00
Look! I changed it!
Member since 4/10 1789 total posts
Name:
Andrew
|
Re: Do you keep your CAC running even when you are not at home?
Here comes my science lesson....
It's a myth that leaving the AC on while you're away at work uses less energy than turning it on when you get home.
Here's why:
Heat goes to where it's not. That's why heat from outside goes into your cooler home. With the AC off, at some point your house will be so hot it can't absorb any more heat. When you come home and turn the AC on, the AC removes all that heat.
But if the AC is on when you're gone, then you've turned your house into a heat magnet. But keeping it artificially cool, there's no limit to the amount of heat it can absorb. It can always absorb more heat. And your AC has to remove that heat constantly. Your AC kicks in and removes some of that heat, then the house is cooler so it sucks in more heat from outside, so your AC kicks in again and removes that heat, and so on.
This means that throughout the day, your house has absorbed way more than one houseful of heat. And your AC had to remove it all. By contrast, with the AC off all day, then it has to remove just one houseful of heat when you come home and turn it on.
Let's say you leave the AC off, and your house absorbs 20k BTU's of heat and then stops, because that's all it can absorb.
Now let's say that you have the AC running instead. The house absorbs 5k BTU's of heat, so the AC kicks in and removes it. Then it absorbs another 5k BTU's, and your AC kicks in and removes that. Repeat that process several times during the day.
EDT to include...
The actual numbers will vary, and I haven't tested this to see exactly how much the penalty for leaving the AC on during the day is, but there is zero question that running the AC all the time uses more energy than turning it on when you get home. This is not a gray area, it's simple physics, and no person with any knowledge of this subject disputes it. Running the AC when you're not home wastes energy, period.
Message edited 7/8/2010 4:20:20 PM.
|
| Posted 7/8/10 4:19 PM |
| |
|
PotofLuck06
Our Baby Boy Is Here!!!
Member since 11/06 13241 total posts
Name:
Betsy
|
Re: Do you keep your CAC running even when you are not at home?
We leave it on, but turn the thermostats up, so it's not running continuously. It's set at 78 (down) and 80 (up).
|
| Posted 7/8/10 4:22 PM |
| |
|
ave1024
I Took The Wrong Road
Member since 12/07 6153 total posts
Name:
That Led To The Wrong Tendencies
|
Re: Do you keep your CAC running even when you are not at home?
Posted by Andrewz00
The actual numbers will vary, and I haven't tested this to see exactly how much the penalty for leaving the AC on during the day is, but there is zero question that running the AC all the time uses more energy than turning it on when you get home. This is not a gray area, it's simple physics, and no person with any knowledge of this subject disputes it. Running the AC when you're not home wastes energy, period.
I agree with this. Keeping the AC on all day during a really hot day will definitely use more electric than turning it hard when you get home.
I had my CAC metered to verify this, and I was using on average 10-20KWH more per day by leaving the CAC on when I was at work.
|
| Posted 7/8/10 4:23 PM |
| |
|
mikeandjess
LIF Adult
Member since 10/07 2278 total posts
Name:
|
Re: Do you keep your CAC running even when you are not at home?
Posted by cgdg61606
I've heard that you should keep it running because if you shut it off and the house heats up, the CAC has to work harder to cool the whole house again.
We just had our central a/c serviced and the guy told us the same thing. We leave it on 78 and have it gradually go down to 73 during the course of the day so when we come home it's nice and cool
|
| Posted 7/8/10 4:39 PM |
| |
|
Andrewz00
Look! I changed it!
Member since 4/10 1789 total posts
Name:
Andrew
|
Re: Do you keep your CAC running even when you are not at home?
ok so i dont follow science... i do leave mine all day... but its for the CATS! they watch TV too!!! big deal!!!
EDT: but it is set much higher during the day and drops to 70 an hr before we get home.
Message edited 7/8/2010 4:52:29 PM.
|
| Posted 7/8/10 4:51 PM |
| |
|
jam11308
Member since 11/07 7273 total posts
Name:
|
Re: Do you keep your CAC running even when you are not at home?
Posted by Andrewz00
ok so i dont follow science... i do leave mine all day... but its for the CATS! they watch TV too!!! big deal!!!
EDT: but it is set much higher during the day and drops to 70 an hr before we get home.
We don't have cats, but my DH goes home for lunch, so we don't set it too high for him
|
| Posted 7/8/10 5:17 PM |
| |
|
Tine73
Member since 3/06 22093 total posts
Name:
*********
|
Re: Do you keep your CAC running even when you are not at home?
Our thermostat has a timer, so while technically the CAC is still "on" it's not running all day when we aren't there.
|
| Posted 7/8/10 5:29 PM |
| |
|
CunningOne
***
Member since 5/05 26975 total posts
Name:
|
Re: Do you keep your CAC running even when you are not at home?
Ours never shuts off once we turn it on for the season. We have it programmed with 4 different times through out the day to adjust the temp. It's higher during the day when we are most likely out and cooler in the evening when we are home.
|
| Posted 7/8/10 6:12 PM |
| |
|
ave1024
I Took The Wrong Road
Member since 12/07 6153 total posts
Name:
That Led To The Wrong Tendencies
|
Re: Do you keep your CAC running even when you are not at home?
Posted by mikeandjess
Posted by cgdg61606
I've heard that you should keep it running because if you shut it off and the house heats up, the CAC has to work harder to cool the whole house again.
We just had our central a/c serviced and the guy told us the same thing. We leave it on 78 and have it gradually go down to 73 during the course of the day so when we come home it's nice and cool
CAC systems typically can run in two speeds (called stages). Stage 1 is normal use, and stage 2 is high speed.
The guy is probably saying that if you leave the CAC off all day, initially when you turn it on the CAC would start in stage 2 (faster cooling - more power) mode to initially drop the temperature. So it does have to work "harder" in the beginning. But for him to say it uses more power, not really true.
The difference (and what I found), is even the extra power it takes initially to cool down, does not equal the amount of power needed to continually "cycle" a CAC system that is left on during the day.
I had a real hi-tech CAC system in my old house that had all sorts of cool monitoring and metering features. On days where I left the CAC on during the day (turning on, off, on, off, on, off to maintain the temperature), I used more KWHs as compared to just turning it on when I got home (or having the timer turn on say an hour before I got home).
Now if you have an incredibly inefficient CAC that takes forever to drop the ambient temperature from 80 to 72 (for example), then maybe you should leave it on all day. The system I had, I can get my temperature down 8 degrees in about an hour or two tops. It was real nice.
|
| Posted 7/8/10 6:17 PM |
| |
|
randella
Love my little man
Member since 8/05 16290 total posts
Name:
Randi
|
Re: Do you keep your CAC running even when you are not at home?
we keep it on...
|
| Posted 7/8/10 6:43 PM |
| |
|
Kissy331
My two miracles!
Member since 5/06 17826 total posts
Name:
Kristen
|
Re: Do you keep your CAC running even when you are not at home?
We keep it on but set the thermostat at 78...By 3PM, the thermostat drops to 75 & then at bedtime 72
|
| Posted 7/8/10 9:12 PM |
| |
|
Kelly9904
Mommy to 2 amazing little boys
Member since 5/05 9306 total posts
Name:
Kelly
|
Re: Do you keep your CAC running even when you are not at home?
Makes more sense to up the temp than turn if off. In heat especially it takes a lot more continuious running to get the temp comfortable again.
When we had our new unit put in the guy told us, to make it worth it you need to really turn it off for like a week. Even if you go away for 3 days not worth it. Just adjust accordingly.
We keep it around 74 during the day. If I am going to be out most of the day I turn it up to 76or higher so the unit doesnt turn on too much!
|
| Posted 7/8/10 11:31 PM |
| |
|
MrsYank
She's here :)
Member since 4/07 3238 total posts
Name:
Mrs. Yank
|
Re: Do you keep your CAC running even when you are not at home?
We leave it off!
|
| Posted 7/9/10 8:31 AM |
| |
|
CrankyPants
I'm cranky
Member since 7/06 18178 total posts
Name:
Mama Cranky
|
Re: Do you keep your CAC running even when you are not at home?
Posted by Andrewz00
Here comes my science lesson....
It's a myth that leaving the AC on while you're away at work uses less energy than turning it on when you get home.
Here's why:
Heat goes to where it's not. That's why heat from outside goes into your cooler home. With the AC off, at some point your house will be so hot it can't absorb any more heat. When you come home and turn the AC on, the AC removes all that heat.
But if the AC is on when you're gone, then you've turned your house into a heat magnet. But keeping it artificially cool, there's no limit to the amount of heat it can absorb. It can always absorb more heat. And your AC has to remove that heat constantly. Your AC kicks in and removes some of that heat, then the house is cooler so it sucks in more heat from outside, so your AC kicks in again and removes that heat, and so on.
This means that throughout the day, your house has absorbed way more than one houseful of heat. And your AC had to remove it all. By contrast, with the AC off all day, then it has to remove just one houseful of heat when you come home and turn it on.
Let's say you leave the AC off, and your house absorbs 20k BTU's of heat and then stops, because that's all it can absorb.
Now let's say that you have the AC running instead. The house absorbs 5k BTU's of heat, so the AC kicks in and removes it. Then it absorbs another 5k BTU's, and your AC kicks in and removes that. Repeat that process several times during the day.
EDT to include...
The actual numbers will vary, and I haven't tested this to see exactly how much the penalty for leaving the AC on during the day is, but there is zero question that running the AC all the time uses more energy than turning it on when you get home. This is not a gray area, it's simple physics, and no person with any knowledge of this subject disputes it. Running the AC when you're not home wastes energy, period.
Well then-I don't care about no stinkin' science.
I want my house cool when I get home, I don't want to wait for it to cool off so we leave it on but set at a higher (but comfortable) temp so it's not blazing when we walk in the door.
|
| Posted 7/9/10 10:34 AM |
| |
|
DiamondGirl
You are my I love you
Member since 7/09 18802 total posts
Name:
DiamondMama
|
Re: Do you keep your CAC running even when you are not at home?
We live in a coop and pay the same monthly fee (an un godly amount  ) regardless so we have been keeping it on these last few REALLY HOT days.
Normally, we shut it off when we go out though.
|
| Posted 7/9/10 11:00 AM |
| |
|
DaisyGirl
LIF Adult
Member since 2/08 1650 total posts
Name:
|
Re: Do you keep your CAC running even when you are not at home?
Yup, keep it running but at a higher temp. I think it's set at like 75 or 76 during the day when we're not home.
|
| Posted 7/9/10 11:32 AM |
| |
|
| Pages: [1] 2 |
