So you already have an air conditioner, or you're planning to buy one... Save money and energy with the previous eight tips (after all, they'll help you use your AC less) plus these five maintenance and buying tips:
1. Adjust the thermostat
If you have central air controlled by a thermostat, use a programmable thermostat to save energy by increasing the heat significantly during the day when the house is empty. You can give up a couple degrees at night, too – especially on the hottest days. You may be surprised to find that the contrast between outdoor and indoor temperatures matters as much as the absolute temperature inside your home. When home, aim to set the temperature at 78 degrees to balance comfort with energy and cost savings. Together with winter energy savings, a programmable thermostat used properly can save the average home up to $150.
2. Clean the air filter
Whether you have central air or a room air conditioner, a dirty filter will reduce its efficiency, making it use more energy and cost more money to do the same job. Check your HVAC system's air filter monthly and expect to change the filter every three months.
3. Get an annual checkup
If you have central air, consider an annual checkup – once should cover both the heating and the cooling season. A professional should be able to diagnose any inefficiencies before you've wasted money on monthly heating and cooling bills.
4. Think small
Cooling one room with a window air conditioning unit requires much less energy (and investment) than a central air system. Ask yourself how you'll use your new air conditioner, and choose the smallest option that works. The government's Energy Star site has a handy guide to help you choose the right air conditioner for your space.
Related: How I Cut Air Conditioning Use in My Cape Cod-Style Home Using the Upstairs Windows
5. Buy Energy Star
Whether you're buying a central air conditioner (which could qualify for a tax credit) or a room unit, efficiency matters. An Energy Star central air system will use about 14% less energy than minimum government standards, and a room air conditioner will save at least 10%. Use the Energy Star Website before making a purchase, because while the vast majority of the 1,000-plus Energy Star window air conditioners barely meet the standards by using just 10% less energy than a standard model, some are clearly a better value. Compared to the typical, these nine models use at least 25% less energy.