Aireco Supply, Inc. (Aireco), founded in 1952, is a major regional heating, air conditioning and refrigeration wholesaler operating in the Maryland, Virginia and Washington, D.C. areas of the US. They are providers of Heating & Air Conditioning Parts, Supplies, and Equipment, Refrigeration, Ventilation, Controls, Hydronic Heating & Air, Ductless Heating & Air, Applied Products, and Commercial, Light Commercial, & Residential.

Boland is a commercial HVAC systems, services, and building energy solutions provider in the DC metro area. They help customers succeed by providing innovative solutions that optimize indoor environments through a broad portfolio of energy-efficient heating, ventilating and air conditioning systems,

The H.M. Sweeny Company is a pioneer distributor of air conditioning, heating, ventilation, and refrigeration parts and equipment.

Harry Eklof & Associates Inc. is a manufacturer representative. They offer training services and also connect the user to the following products: Plumbing, HVAC, Bath Fixtures, Sump Sewage, Tools.

The Mechanical Contractors Association of America (MCAA) serves the unique needs of approximately 2,600 firms involved in heating, air conditioning, refrigeration, plumbing, piping, and mechanical service.

The National Institute of Standards and Technology (NIST) was founded in 1901 and is now part of the U.S. Department of Commerce. NIST measurements support the smallest of technologies to the largest and most complex of human-made creations, ranging from nano-scale devices so tiny that tens of thousands can fit on the end of a single human hair up to earthquake-resistant skyscrapers and global communication networks.

OTS R&D provides research and development services with a focus on thermal and energy conversion systems. Much of the work centers around the HVAC&R and automotive industries. It provides consulting services, software development, educational workshops, and experimental assistance for a variety of customers and clients.

Located outside Baltimore, Maryland, Powrmatic, Inc. is a well-known, long-established manufacturer of heating, cooling, and air-cleaning equipment for the industrial and commercial marketplace. A subsidiary of the Stamm International Group, Powrmatic manufactures a complete line of direct-fired and indirect-fired heaters, cooling systems, and media and electrostatic air cleaners that can be customized to fit customer needs.

The R.E. Michel Company was founded in Baltimore, Maryland in 1935 as a supplier to the home heating oil burner industry. Still family owned and operated, they have grown to be one of the nation's leading wholesale distributors of HVACR equipment, parts and supplies.

Shore Distributors, Inc. are wholesale distributors of HVAC and plumbing supplies across Del-Mar-Va. They have training programs and product seminars too.

Stulz-ATS is a globally renowned manufacturer of environmental control equipment including a full line of energy-efficient precision air conditioners, ultrasonic humidifiers, and desiccant dehumidifiers. They also provide cooling solutions and services for mission critical applications through the design and manufacture of highly energy efficient temperature and humidity control equipment for commercial and industrial applications.

Thos. Somerville Co. is a complete full line distributor of plumbing, heating, and air conditioning supplies.