G.W. Berkheimer Inc. Co. 57561 Nagy Dr. Elkhart IN 46517 is a leading supplier of HVACR products and solutions and has been in business for over 75 years. Areas Served: G.W. Berkheimer operates HVAC supply houses in Illinois Indiana and Kentucky. What Brands Does G.W. Berkheimer Sell? G.W. Berkheimer carries brand names like Armstrong Honeywell Spacepak White Rodgers Mitsubishi Grundfos State Water Heaters Aprilaire Amana Milwaukee as well as many other HVAC supplies.