Not only might you be able to get a cash for appliances rebate or act on other incentives when buying a central-air conditioning-system but you can also take advantage of perks to keep your air conditioner running at peak efficiency, which will help it last longer and save you even more dough.

The Database of State Incentives for Renewables & Efficiency lists incentives for tuning up a central-air system, including sealing ductwork. Typical rebates range from $75 to $100. Check DSIRE or call your utility company or look on its Web site.

If you're in the market for a new central air conditioner, review our brand-reliability data and learn more about split-ductless systems (both available to subscribers).

—Gian Trotta

Essential information: Undertake this air-conditioning maintenance on your own and learn how to cut summer cooling costs.