How to Use a Timer With an Air Conditioner. Setting up a timer for an air conditioner is a cost efficient move. You don't have to run your air conditioner when you aren't there to enjoy it, but you can still have your home comfortable when you get there.
Buy an air conditioner timer. There are many to choose from and they are relatively inexpensive. Regular timers may not be durable enough so be sure to get a timer that works with appliances like air conditioners (See the Resources).
Choose a more expensive air conditioner that has a timer built in. You can also buy a less expensive air conditioner and get a timer for it.
Set the timer to turn off at the time you normally leave your home. Also set the timer to turn on around an hour or so before you come home. This way your home will be cool for you when you arrive. The idea is for you to save money, not to be uncomfortable.
Remember to adjust it when you are home on weekends. Some timers have more than one setting for on and off--take advantage of these to adjust your weekend schedule.