What is the best settings for the A/C thermostat during the summer that is energy efficient?

I live just outside Chicago, IL. Work from 11am-7pm. What is the most efficient temp to set the A/C to stay cool, yet not waste energy?

What is the best settings for the A/C thermostat during the summer that is energy efficient?
Do you have a programmable thermostat? If not, that's the first step toward efficiency.





Set it to cut off (ie 85 or so) at 10 or 10:30. As early as possible and still be comfortable until you leave.





Then figure out how late you can turn it back on (at whatever temperature you like) and have it comfortable when you return. That's a trial and error deal.





The AC basically pumps out heat that flows in from outside. The cooler your house (compared to the outside) the faster that unwanted heat flows in. If your house was the outside temperature, no heat would flow in. So keeping your house cool when you're not home works against you by causing more heat to flow in, and wastes energy.
Reply:its simple, the cooler you set it the more energy it uses.





Set it at the warmest temp that is comfortable, when you leave for work, turn it up a bit and turn it back down when you get home (some systems can be pre-programed to adjust by the time of day, check the owners manual of your A/C)





Limit anything that lets cool air out like opening doors.





Make sure your A/C unit is in a shady spot, if it is in direct sunlight it will have to work much much harder to create the same amount of cooling power.





close the doors to rooms that you are not going to be in and shut the air vents to those rooms, this way you are cooling the smallest area possible.
Reply:well, i live in the desert, so during the day i turn the thermostat up really high to 90 (cause my house gets almost that hot in the summer), even when I'm there, and turn up the ceiling fans (cause it costs pennies to have those running), cause it's cheaper to have it on, but on a high temp than turn it off and on when you use it or don't use it ... then, only when the sun sets, and I'm getting ready for bed, do I turn it down to 80, which is cool enough and barable (w/ ceiling fan on) as opposed to having it on 78 or cooler. those two degrees makes a difference in savings!





so i would suggest to do the same where you live ... set the temp a little hotter than what the house heats up to during the day, then turn it down to a comfortable temp when you get ready to go to sleep.
Reply:78 Degrees.
Reply:never turn the air conditioner nor heater is best way to save
Reply:It is purely subjective. Consider getting an electronic thermostat. You can leave the A/C off until about 5:30 PM, then set it for 78 degrees. Then set the thermostat to shut off at about 2:00 am. You will be using electricity for 8 1/2 hours.
Reply:I hope your question is not suggesting that you are walking out in the morning and leaving the A/C turned on while you are not there. If so, then I've never heard of a more wasteful use of energy.
Reply:Get a programmable thermostat and let it do it for you. It will automatically adjust the setting for the time of day.
Reply:Depends on the humidity. When we're home, we set it as high as is comfortable, when we're away, we set it as high as the plants and animals will live comfortably