Weekend Project: Even as summer enters final weeks, save by taking advantage of cooling incentives

Cool roofs are a hot item, with no less an advocate than Energy Secretary Steven Chu promoting their potential to save energy during an appearance on The Daily Show With Jon Stewart. And while the U.S. Department of Energy is lacking in some ways when it comes to reducing energy use, the United States Postal Service has unveiled a new green roof (shown) atop its 2.2 million square foot mail-processing facility on Manhattan's West Side.

While such a project is too ambitious for your home, you should take advantage of the plentiful federal, state, and utility incentives for air conditioning and other improvements and equipment that will help you reduce your cooling and heating costs. (Read "Cash for Clunkers Moves to Appliances. Money Back for Your Old Kelvinator?" for details on the federal government's $300 million State Energy Efficient Appliance Rebate Program.)

Air Conditioner Tune-Ups
There are several state and local utility incentives for central-air systems. Rocky Mountain Power and the Long Island Power Authority provide $100 rebates for tuning up central-air-conditioning systems.

Duct Insulation
As much as 30 to 40 percent of your cooling energy can be lost through leaks or when uninsulated ducts pass through uncooled spaces like the attic and garage. "Its certainly reduces the impact of a very efficient central-air unit if your ducts are leaking like a sieve and you have inadequate attic insulation," says Ed Clark, director of communications for Austin, Texas-based Austin Energy. That utility is offering rebates for duct-system performance testing, sealing, replacement, and insulation.

Programmable Thermostats
Today's best programmable thermostats can help you cut heating and cooling costs by up to 20 percent. Utilities in 34 states offer rebates of up to $70 for programmable thermostats—enough to cover the entire purchase price of seven of the 10 recommended models in our ratings (available to subscribers).

Whole-House and Ceiling Fans
California's Sacramento Municipal Utility District offers a $100 rebate on a whole-house fan system. These work by pulling in cool air from open windows and exhausting hot air from vents in the upper part of the home. Pasadena Water & Power will give its customers a $50 rebate on a ceiling fan, provided it's outfitted with an energy-saving compact fluorescent lightbulb and you buy it from a local retailer.

Weatherization Projects
Weatherization products such as energy-efficient windows, insulation, and doors can qualify for a federal tax credit of 30 percent of the cost, up to a $1,500 maxiumum. California's Alameda Municipal Power will pay up to 80 percent of caulking, weather stripping, and building insulation costs. National Grid offers customers in Massachusetts a 75 percent reimbursement up to $2,000 for similar improvements. The Orlando Utility Commission offers a $1-per-square-foot rebate on Energy Star-qualified windows and a $100 rebate for installing window film. Note that payback for your investment in these types of projects can be much longer than it is for other improvements you'll make.—Gian Trotta | e-mail | Twitter | Forums | Facebook

Essential information: See our maintenance checklist for air-conditioning systems and learn how to add a ceiling fan. Our latest report on cooling (available to subscribers) provides details on window, portable, split-ductless, and central air conditioning.