If you're in the market for a new heat pump or central air conditioner, add the government's new Energy Star symbol to your list of things to look for.

Why? Because the Energy Star logo means the unit is at least 20 percent more efficient than the products currently meeting minimum federal government standards.

Experts at the Trane Home Comfort Institute explain that, in terms of cooling, only heat pumps and central air conditioners that have a Seasonal Energy Efficiency Ratio (SEER) of 13 or higher qualify for the Energy Star label.

The SEER is a measure of a unit's cooling efficiency. The higher the SEER, the higher the efficiency. The higher the efficiency, the lower the energy bills.

The U.S. Environmental Protection Agency (EPA) created the Energy Star program to help increase the efficiency of heat pumps and central air conditioners being installed in homes. Doing so will dramatically reduce the nation's energy consumption.

It will also help utilities offset their peak loads and avoid constructing costly new power plants. Homeowners gain the added benefit of saving money because more efficient equipment costs less to operate.

To make the high efficiency models easier to purchase, EPA is offering financing assistance through special Energy Star loans from participating banks and other financial institutions. The loans have lower interest rates, longer payment periods or both.

It also stresses the importance of purchasing the properly sized system. A unit that's too small will lack the capacity to keep you cool on the hottest days. A unit that's too large will cost more to purchase, more to operate and may not remove enough humidity to keep you comfortable. Your air conditioning dealer can help you determine the correct size for your home.