Air condition energy usage?

Question

it it more energy efficient to turn off your air condition during the daytime and turn it back on at night or to just let it run all night.

if the air condition is set at 75 degree and the outside temperature is 90degree

thank

Answer 1

duhh..

Answer 2

It's better to turn it off.

Answer 3

I could tell you a lot about this, but it'd take too long...

I've lived in Austin TX (hot climate in summer), San Jose CA (warm during day but cool at night, ocean breeze), NJ and PA (and a dozen other places, but let's stick to the above).

First--are you talking about turning off your air conditioner AND OPENING YOUR WINDOWS?  Because if you live where it's humid, letting that fresh air in will cause condensation that will mess up your AC system.  Happened to us in Austin.

San Jose?  Take advantage of the cool night air--open your windows, then close your windows in the morning to keep the cool air in.

NJ?  Well, we lived in a brick house in the woods. Again, enjoy the cool night air, then shut the windows in the morning and let the bricks and trees keep the house insulated from day heat.  We didn't even OWN an AC in this 1947-built home.

PA?  Well, we're halfway up a hill and don't have trees like in NJ.  IT DEPENDS on the weather.  Right now it's hot and muggy--we've found it's best to set the AC on 80 degrees at night and to NOT open the windows, because that lets the moisture in so you feel hot and sticky all night.  Ie., the AC does NOT  fire at night, but the closed windows keep the air dry.

RIGHT NOW?  July 10, 5:43 PM?   It's 85 degrees outside and 79 degrees inside, windows closed,  WHICH MEANS the AC hasn't fired all day.  But you know, with the dry air inside and an overhead fan going at a lazy speed, I haven't noticed feeling hot at all.  Until NOW, that is, now that it's been brought to my attention (just kidding).

Answer 4

It's more efficient to shut it off during the day.  Energy Star schedule guidelines are as follows for maximum efficiency:

85 when your away, 78 when you return, 82 while you sleep, and 78 when you awake.  

I personally prefer to keep mine at 77 when I'm home or asleep, and have it shut off right before I wake up and set to 85.  This gives the air conditioner a good 8-10 hours of being off during the day.

Answer 5

I run my at 77 as we are home most of the time.