The Air-Conditioning, Heating, and Refrigeration Institute — the trade association representing manufacturers of comfort and commercial refrigeration products — reported encouraging shipment figures from April 2010.

U.S. shipments of central air conditioners and air-source heat pumps totaled 523,121 in April 2010, up 25% from a revised total of 419,268 units shipped in April 2009. U.S. shipments of air-source heat pumps increased 31%, to 170,670 units, up from a revised total of 131,157 units shipped in April 2009.

U.S. shipments of air conditioners increased 23% to 352,451 units, up from a revised total of 288,111 units shipped in April 2009. Year-to-date combined shipments of residential central air conditioners and air-source heat pumps increased 12%, to 1,554,444 units, up from a revised total of 1,388,055 units shipped in April 2009.

The year-to-date total for heat pump shipments increased 14%, to 556,387 units, up from a revised total of 491,193 units shipped during the same period in 2009. Year-to-date shipments of central air conditioners increased 12%, to 998,057 units, up from a revised total of 896,862 units shipped during the same period in 2009.

U.S. shipments of gas warm air furnaces increased 20% in April 2010, to 149,791 units, up from 125,000 units shipped in April 2009. Oil warm air furnaces, however, decreased 9%, to 2,167 units in April 2010, down from 2,368 units shipped in April 2009.

Year-to-date U.S. shipments for gas warm air furnaces increased 21%, to 656,647 units, compared to 543,338 units shipped during the same period in 2009. Year-to-date U.S. shipments of oil warm air furnaces increased 25%, to 15,486 units, compared with 12,356 units shipped during the same period in 2009.