That was some summer! Many regions of the country, those with relatively modest cooling degree-days, saw high temperatures and humidity more common to cities like New Orleans and Houston.

Cooling degree-days in Boston, MA were up 16%; Buffalo, NY, 21%; and Harrisburg, PA, 19%. Even Bangor, ME, where central cooling is so rare as to be considered exotic, experienced a 37% spike in temperatures.

For many of these markets, it was add-on time rather than replacement installations. That meant first-time installations of ductwork, controls, and air-handling equipment.

The hot weather couldn’t go on forever, and the moderation is reflected in shipments of unitary products. Another damper on shipments was the unseasonably cool weather on the West Coast — testament to La Niña, which kept ocean and land surface temperatures below normal.

Decreases in cooling degree-days were registered in markets like Los Angeles, CA (down 12%), Portland, OR (down 21%), and San Diego, CA (down 43%).

For the first time in seven months, shipments showed a dip when compared to the same period a year earlier, but year-to-date shipments are on a track to exceed last year’s record output of 6.2 million.

August shipments (527,065) showed a modest decline of 4% from the previous August. Year-to-date shipments of 4,961,259, however, are up 5% for the same period last year.

Within those numbers, August heat pump shipments of 104,366 were down 4%, but year to date, shipments of 921,163 represent a 4% gain.

Residential work

The vast residential add-on and replacement markets account for nearly 60% of the robust shipment figures. It is estimated that about 40% of America’s single-family homes have central air conditioners (another 23% have one or more room units).

Also, about 30% of units in multifamily homes have central cooling. This puts the potential replacement market in the tens of millions of units.

New residential construction accounts for another 26% of unitary, and light commercial absorbs another 10%.

Other favorable factors include the all-important interest rates, which have stayed moderate, a 4% annual growth rate, and no inflation on the horizon.

Some forecasters see a new home construction market at 2 million units — the highest during the past two decades.

Relatedly, shipments of room air conditioners for the first three quarters are at a gaudy 5.8 million, up 43% for the period, and already exceeding any output for the last quarter of a century. For the past 25 years, shipments have hovered in the 3 million to 4 million range.