Although most people just assume that H.V.A.C contractors are a part of the central heat and air contractors that install both furnaces for heating and air con units for cooling, air conditioning contractors have a private history that began in the 1900s when machines for building heating and cooling units began to be established. H.V.A.C contractors became a separate part of the heating and cooling industry in 1946 and were represented by their own groups exclusively concerned with H.V.A.C.
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