In the first survey of its kind by the RPA, its contractor members reported data on more than 7.5 million sq. ft. of radiant heating installations. The results broke down the market of radiant heating installation for 1998.

"In the past, the amount of tubing sold nationwide was the only question asked. Now we know where and how it's being used," said RPA president Larry Drake.

The RPA, after making a few of its own guestimates on the results, found the survey to confirm what it had expected of the industry, according to Drake. Following the overwhelming percentage of residential installations, the survey reported commercial installations at 14 percent of the market, and snowmelt finished at 10 percent.

The survey also addressed the increase in alternative methods of installing radiant heating by breaking down installation methods as well.

Slab on grade, the oldest and most common method, accounted for 51 percent of installation methods. Thin slab, or sandwich, came next at 36 percent. The staple-up method of installation reached 11 percent, and the rest went to wall installation at 0.8 percent and ceiling installation at 0.4 percent of the market.

Only the low percentage of staple-up installation surprised Drake. "There was a lot of talk about that method. The number was lower than we expected," Drake admitted.

Of the pre-manufactured panels used, contractors reported that 74 percent were baseboard radiators, 25 percent were wall-mounted radiators and 0.5 percent were ceiling-mounted.

Drake thinks the 750 members surveyed by the RPA are a good representation of the industry. The organization plans to continue the survey annually.