ARLINGTON, Va. - Air source heat pump shipments totaling 173,009 for April, were up 2.5 percent as compared to the same month last year, according to the Air-Conditioning and Refrigeration Institute (ARI). The increase is not as large as March's shipment spike, however, overall year-to-date heat pump shipments, totaling 748,279 units, are up 22 percent over 2005.

"As consumers make choices pertaining to heating and cooling their homes, the improving efficiency of heat pumps, in conjunction with rising costs of other heating sources, make the heat pump a logical choice," said David Martz, ARI's vice president of administration and statistics. "The ease of use in a system that both heats and cools the home adds to the allure."

Combined U.S. factory shipments of central air conditioners and air-source heat pumps totaled 542,542 units in April, down 20.1 percent. The year-to-date combined total of 2,522,530, however, is up 8 percent from January through April's 2005 totals.