I'm thinking about installing an AC unit in my house, but I'm a bit afraid of the increased energy costs. Do you leave it running all the time on hot days or do you turn it off when no one is home to save electricity?
We do not run our A/C all day. We have all of our thermostats on timers so that we can actually regulate the temperature up to 6 times a day. We make it colder at night (just before bed) and then warmer in the morning when we're all leaving for school and work. One thing we don't do, however, is ever turn it completely off. Allowing the house to completely heat up and then re-cool down is less effective than just maintaining a moderate temperature during the day, even if no one is home. We also watch the weather. If it is supposed to get cool at night we'll turn off the A/C and open windows, and run ceiling fans. This keeps the house cool without the added expense of running the A/C. My husband has window units in his 3rd floor office at work, and he does not run them all the time... only when he's in the office. It is a small enough space that it heats up and cools down quickly, so I think that the cost benefit is more in favor of only running the unit when he actually needs it.
If you don't have the option of timers, set it to 75 so the home stay comfortable when you are out. I agree, allowing the home to get too hot will take longer to cool it down and you will use more energy in a short period of time. If you don't have an AC unit that you can control the temp on, like an older unit, set it on the lowest output possible.
