DNV GL is a global quality assurance, software solutions and risk management company. They provide classification, technical assurance, software and independent expert advisory services to the maritime, oil & gas, power and renewables industries. They also provide certification, supply chain and data management services to customers across a wide range of industries.

Dogu Air Conditioning (DOGU Iklimlendirme) started manufacturing ventilation and air conditioning equipment in Izmir, Turkey, back in 1999. It also manufactures Air Handling Units (AHUs), Rooftop Packaged Air Conditioning Units (Rooftop), Heat Recovery Devices, Air Distribution Equipment, and Kitchen Ventilation Devices according to European norms.

Done-Rite Plumbing & Rooter is the premier plumbing company in Orange, California, USA. They are a full-service plumbing contractor offering everything from water heater installation & repair, drain cleaning sewer line repair & installation, and general plumbing services. They service the entire Orange County area and can be out to any property in the area same-day for plumbing services.

Dring Air Conditioning & Heating is a family-owned business which makes them a rare breed in this era of big box stores and Internet commerce. They first opened their doors in 1953, and as their core of loyal HVAC heating and cooling customers has grown, their area of service has expanded.

DT Air Conditioning & Heating is Texas' renowned expert heating and cooling company. They offer furnace and air conditioning services in and around Plano, Texas, USA.

As a pioneer Gas and Heating Company in West Yorkshire, DTR Gas and Heating knows what exceptional and reliable workmanship means. They are providing clients with a wide range of services, all with guaranteed quality and precision. From the beginning stages of the project all the way to the completion of the process, they work side-by-side with clients every step of the way.

Du-Co Ceramics is a technical ceramics manufacturer using steatite, cordierite, magnesium oxide, alumina, mullite and forsterite. Ceramic componants are produced by dry pressing and extrusion methods.

DUCO Ventilation & Sun Control focuses on health in all its developments in the field of ventilation and sun protection systems, always with a nod to optimal occupant comfort and maximum energy efficiency.

For over 30 years, Duct Doctor USA has been providing quality air duct cleaning for both residential and commercial customers. Duct Doctor was founded by a board-certified allergist in 1985 with a mission to improve the air quality of homes and workplaces.

With manufacturing and distribution facilities dotting the planet, Ductmate is one of the largest HVAC system components manufacturers in the world, and the largest in the United States. They are pioneers in innovative duct and HVAC solutions, making Ductmate the single-source solution provider for engineers and contractors, worldwide.

Since 1928, Dunkirk has delivered innovative, efficient, and dependable home heating products to professionals, building owners, and homeowners. Their products inventory includes condensing boilers, water boilers, water heaters, storage tanks, thermostats and multiple boiler control units.

Duquette Refrigeration has provided commercial refrigeration and HVAC service, installation, and 24/7 emergency repair to businesses throughout New England since 1986.

Dura Products, Inc is a state-of-the art Indiana based manufacturer of metering, pumping and dispensing systems for the DEF, AG, and turf Chemical industries. Founded by owners with decades of knowledge in farming and the chemical sales industry, Dura Products Inc goes beyond excellent design to incorporate innovative, versatile and durable transfer pump solutions with the end consumer always in mind.

Duratrac, Inc. provides a host of professionally engineered connectors designed to perform optimally with your residential and commercial gas and water heater applications. All Duratrac flex features durable stainless steel construction without tapering at the ends to help insure optimal flow, while our end fittings and valves are zinc iridate plated to prevent corrosion

DuraVent is the recognized technological leader in the venting industry. Consistently first to market with new innovations, DuraVent is committed to providing safe and technologically advanced venting.

Duro Dyne Canada Inc. manufactures and distributes the most complete line of sheet metal accessories and equipment for the heating, ventilating and air conditioning industry in Canada.

Established in 1995, Dusty Ducts, Inc. is certified as a minority-woman-owned-small business. As a Michigan corporation we provide HVAC Restoration, Indoor Air Quality and Energy Conservation for clients throughout Michigan and across the Midwest United States.

Founded in 1859, the Deutscher Verein des Gas- und Wasserfaches is the German association for gas and water with headquarters in Bonn. Its official English translation is the German Technical and Scientific Association for Gas and Water.

E Flow Technologies is a global company which produces the energy efficient fan-packs for a vast variety of AC & EC motor solutions and a quick return on investment for HVAC, refrigeration, ventilation and engine cooling industries.

The E.ON Group is one of Europe's largest operators of energy networks and energy infrastructure and a provider of innovative customer solutions for 50 million customers. Thus, they are decisively driving forward the energy transition in Europe and are committed to sustainability, climate protection, and the future of the planet.

Eagle Mechanical, Inc. is a HVAC, plumbing, process and piping mechanical contractor with 30+ years’ experience. They help customers to purchase, install, maintain or replace any heating, air conditioning, refrigeration and plumbing systems. They specialize in industrial and commercial facilities, like hospitals, office buildings, schools, and government facilities.

Earth City Distributing is a renowned distributor of HVAC solutions and equipment with headquarters located in Chesterfield, Missouri, USA.

East Coast Metals products, professional service centers, and technical support combine to give the user exceptional service before, during, and after the sale. They are dedicated to fulfilling this commitment every single day. Their mission is to deliver the quality HVAC products the user needs, when they need them, and provide expert technical support.

EATA EQUIPAGGIAMENTI REPRESENTS A LEADERSHIP IN THE INDUSTRIAL REFRIGERATION AND AIR CONDITIONING MARKET.

Eco Ketelservice Verhuur bv has steam, hot water and warm water installations and all required accessories for hire. Eco Steam Trading & Consultancy bv sells the complete product range of boiler house components by Bosch Thermotechnik. The rental fleet includes steam, hot water and warm water installations, deaerators, automatic expansion units, oil tank containers, boiler feed water tanks and water softeners, as well as economizers.

Based in Warminster, United Kingdom, Ecobubl design and supply renewable energy solutions. They offer product training courses for air source heat pumps, electric & heat batteries, and also mixergy hot water tank. They also offer solar PV and electric battery storage Installations, throughout Wiltshire, Dorset, Somerset and parts of Hampshire, in the UK.

EcoFlow Tech is a revolutionary mobile power company that is reinventing the way the world accesses energy. As makers of industry-first, smart and powerful mobile power products, EcoFlow’s mission is to harness new technologies to foster inclusion and help raise standards of living in areas of the world where power shortages stunt economic growth and development.

EcoMech Geothermal Heating and Air Service in Atlanta is a focused team of dedicated heating and air professionals providing sustainable energy heating and air solutions under one roof.

EcoRebates is the industry’s largest product offer platform for Residential and Commercial products. They support energy efficient product categories, including Major Appliances, HVAC equipment, Water Heating, Boilers, Plumbing equipment, Smart Home products, Insulation and more.

EcoSync is a multi-award winning Smart Temperature Control System, born out of Oxford University. With EcoSync, businesses can reduce their heating-related carbon emissions and energy bills by up to 50%. It achieves this by synchronizing heating with occupancy levels, on a room-by-room basis. With added control over temperature settings, businesses can improve energy efficiency, boost their sustainability profile & lower their heating bill.