Installing and servicing furnaces, a/c systems, and ductwork may not be the same as installing vent-free products, but the training is similar.
Last year, 1999, was a good year for sales of vent-free supplemental direct heating appliances. According to the Vent-Free Gas Products Alliance, a coalition of 26 members of the Vent-Free Gas Products Division of the Gas Appliance Manufacturers Assoc-iation (GAMA), sales of these products were three times as high as sales of vented direct heating products, totaling 1,044,936 units.