No, turning off A/C is not most cost-efficient way to cool your home

Makes sense that turning off your air conditioning means it should be cheaper, right? Team 12’s Michael Dounda has the answers for you.

[jamesadams]

Lots of comments. But I live in Houston Texas. When I leave home for extended days. I set my a/c temp to 78°-80°. I've turned the unit completely off in the past and the house temp in 3 days exceeded 85°. My normal a/c setting is 74°. It took 10 hours of continuous running of my unit to get back to 74°. And I approve this reply. 😊

[joeeoj]

Lived in 2 extremes. AZ and SoCal mountain desert. If your night air is hot, the then the AC is an all day occurrence. If the night air cools use it to your advantage til morning. I run my AC 3-5x a day for about 30-60 minutes. Morning, noon, evening and night. With a soft start my bill has dramatically dropped than running my 6 ton unit on thermostat. In auto mode, the compressor may turn up and past 5 times. The current draw on start up adds up quick on the cash register. I’ve had the unit off and inside read 80 degrees but felt cooler in contrast to the 105 degree plus humidity outside. Once the internal framing of the house is hot, you lost the battle.

[earthisfat]

If you use window units it absolutely saves money to turn them off. I do it every summer and it knocks almost half of my bill off on the days I work. When I'm home and they run all day they use more.

[ericha]

In Fresno where its 105 they still shut it down and it hits 90 inside. 82 degrees is better than off

[fallguy]

Who the hell wants to have their home in the 80’s

[HLTrizzay]

What’s the point of setting the temperature to the same as outside?

[gr]

That’s why you get a thermostat with a schedule to come at a certain time or temperature when you’re not home

[Niqua]

I was told as a child to lower my thermostat and as I got older I realized it cost me more. Cold air cost more then hot. I'm learning to set it up so, it will be more comfortable for me and my family in our home. And save me money. My parents ain't good parents anyway. So ...yeah. After years later I asked and they said don't do that? As I looked at them crazy. Like, wtf!? I'm in my 30's now so, I'm slowly understanding and I'm sick of my bill being 300 to 400 $ and more. I'm barely home. I work nightshift sometimes.

[Clouds-sudc]

Yes you can save air conditioning bill by having a White roof, which are called a cool roof. What they do is they reflect the sunlight heat away from the surface back to space leading your roof to less heat absorption, leading the inside of your temperature house cooler automatically because when there is no sun heat being absorbed on your roof that would lead to much less heat radiation coming inside your home to prevent from warming up the temperature. This will make it easier for your AC to cool down your home much quicker and the cold air inside your home will last thing longer.

[tjismyname]

Setting your AC to 80° or even 78° in southern Arizona is insanity. As for the lunatics that actually turn off their AC at all in hot weather? God help them lol.

[TropicalVibesHD]

This is incorrect: if you turn off your AC (unless you live in a glass house/greenhouse) the temperarure in your house will NOT rise much past that of the outside. Rest assured it will not rise to continuously or exponentially to infinity or that of the surface of the Sun! In fact, as the house heats up the rate of heating up slows until equilibrium temperature is reached i.e. the temperature at which heat lost=heat gain. The heat capacity of most of the contents of the house is not that significant (we are talking temperature difference of 75F to 95F in Summer versus 75 to 0 F in Winter)...how much energy does it take to "heat" a wooden table from 75F to 90F...assuming it gets that warm at the table?! Not that much, relative to heating the entire volume of the home. Basically the specific heat capacity of most household furniture material such as wood, plastic etc is very low <20% that of water. Other items in the home with high specific heats have small mass and so overall the heat capacity of house contents would not act as a significant reservoir of heat. That argument made by the DOE consultant applies more in Winter when the temperature swings are greater. Heat absorbed by an object(joules)=mass(Kg)×temp difference (in Celsius)× specific heat of material of object(J/kg/deg C).
During the day the heat pump (i.e.A/C) has to dump its energy onto a higher temperature than at night so it is less thermodynamically efficient (2nd law of thermodynamics). In certain parts of the grid electricity also cost more during peak hours when there is variable price i.e. higher rates during the day. Finally if you are gone for 4 months would you leave the AC on or turn it off? Same priniciple applies to being gone for 4 hours.

[johnwang]

Maybe just have it a degree or two higher when you're not home and find a way to put a power meter on the AC so you could actually tell if you're saving power throughout the day. You'd also want to graph outdoor temperatures to see how many degree days of cooling you're trying to achieve (the weather website Weathersparks used to have historical cooling and heating degree days graphed as well as predicted degree days but info has been increasingly monetized so I don't know if such convenient data is still available for free).

Like everything else, there will be an optimal sweet spot and without the ability to measure and rate it to the actual weather being experienced, you'll never find that sweet spot and being off by a little might make a big difference.

[tkmj]

I never in my life turned down the A/C i keep it running 24/7 all seasons even in winter it's hot too, i live in Saudi Arabia for god sake it's burning hot in here, this is why air-conditions in Saudi breaks down every 4 years and we buy a new one.

[junior]

That’s the biggest lie I’ve ever heard. I live in a one bedroom apartment in central Florida and only turn my ac on between midnight and 6 am due to off peak power discounts. And my apartment is usually 75 degrees or under for most of the day. When I get home it doesn’t feel like an oven nor are all of the materials hot. And it takes about 15 minutes for the whole apartment to reach my preferred 65 degrees for sleeping

[Shinbi]

So dont turn off your AC turn it up to the temperature its going to be in the house anyway when you used to turn it off... gotcha. That makes all the sense.

[priyaj]

I think they are talking about leaving the AC on when you leave the home for 1-1.30 hours. Otherwise this is just a silly advice.
There are people who would switch off AC when they go out of the room to get a glass of water thinking that would save on bills. May be this whole clip is meant for them

[justincynor]

I disagree. What they are saying makes no sense.

[BLCKSTEEL]

Meanwhile the other 2/3rds the planet lives without ac….

[DLFfitness]

I use my AC to make my home bearable. I have no desire to create a huge electric bill. 78 when I’m home, and 85 when I’m away.

[bondnikunj]

Put solar on roof, best way to save bill. These r stupid case based scenerios