Isotherm, Inc. is a company specializing in the design and fabrication of heat transfer equipment for industrial refrigeration, petro-chemical and industrial process applications. The company's forte is enhanced heat transfer for natural refrigerants such as ammonia, carbon dioxide and hydrocarbons. This unique advantage has resulted in Isotherm products being compact with ultra low charge. The products include pressure vessels, shell and tube evaporators and condensers especially geared towards high pressure heat pump systems. The company also manufactures semi-welded plate and frame heat exchangers.

It holds ASME certification for "U" and "UM" stamps and the National Board Repair stamp "R". It is also qualified to produce CE marked equipment under the European Pressure Equipment Directive (PED) and Det Norske Veritas (DNV). The designs per TEMA standard are also common. It has a strong engineering department with highly qualified and experienced engineers.