Now that Summer is fully upon us, many of those with and without central air conditioning are starting to feel the heat. If you are considering cranking that system to arctic weather, however, you'll likely want to keep your electric bill in check as well. Wheter you are using window units or, like many new consumers, opt for a central air conditioning system, here are some tips to help you reduce your energy bill.Central AirWhile central air conditioning systems have some distinct advantages in terms of efficiency, you are also constantly cooling your entire house rather than designated areas. As a result, your best bet is to load up with an adjustable thermostat and place it on a timer that raises the temperature while you are out of the house and lowers it about an hour before you get h