“May was a particularly strong month, with even the lowest quartile showing year-over-year growth which is a rare occurrence,” said association economist Andrew Duguay.

May sales for HARDI members were up 17.9 percent, the best growth since November 2010.

The figures are from the Heating, Air-conditioning and Refrigeration Distributors International’s Targeted and Regional Economic News for Distribution Strategies report. Sales were up in all seven U.S. regions; six had double-digit increases.

“May was a particularly strong month with even the lowest quartile showing year-over-year growth which is a rare occurrence,” said HARDI economist Andrew Duguay. “Eighty-four percent of members reported a positive May ’12 vs. May ’11, suggesting the recovery among distributors is broadening. Business cycle momentum is clearly positive at this point.”

  Another measure, “Days sales outstanding” (how quickly customers pay their bills) declined after increaseing eight of the last nine months. Distributor productivity, reflected by sales per employee, shot up 26 percent in May.

  “There certainly haven’t been many months showing these kinds of growth numbers for quite some time,” said HARDI Executive Vice President and COO Talbot Gee. “Strong sales and an early start to the season have started to deplete inventories so I wouldn’t be surprised to see aggressive restocking of value products and repair components.”