Johnstone Supply is one of the leaders in heating, ventilation, air conditioning and refrigeration (HVACR) in the United States. The company has more than 350 stores throughout the United States. It offers products from numerous manufacturers, such as A.O. Smith Corp., Alcoa Global Fasteners Inc., American Water Heater Company, Atlantic Chemical & Equip and Alset Engineering, to name a few. Johnstone Supply has an extensive stock of more than 50,000 parts, supplies as well as equipment.