DHD Cooling offers a full service capability to the manufacturing, HVAC, thermal power plant, industrial and chemical industries, offering a bespoke service tailored to one’s exact cooling tower system requirements.

DHL Group is the world's pioneer logistic company. The DHL Group connects people and markets and is an enabler of global trade. It aspires to be the first choice for customers, employees and investors worldwide. To this end, the Group focuses on growth in its profitable core logistics businesses and accelerating the digital transformation in all business divisions.

Dial Plumbing has become the leading gas piping and plumbing service business in Brevard County. Owners, Steve Packard and Allen Deibert. It has the best installation and service personnel on the central east coast of Florida to exceed the needs of the customers.

Founded in 1988 with offices in Kansas City, Austin and Denver, Dialectic is a non-traditional mechanical, electrical and plumbing engineering firm that brings buildings to life. With deep expertise in a range of verticals – including distribution, cannabis, multifamily, senior living and retail/restaurants – they know that true success comes with partnering as an extension of the team.

Digital Twin Consortium is a global ecosystem of users ,who are driving best practices for digital twin usage and defining requirements for new digital twin standards. It coalesces industry, government and academia to drive consistency in vocabulary, architecture, security and interoperability of digital twin technology. It advances the use of digital twin technology from aerospace to natural resources.

Dimplex offers a variety of both indoor and outdoor electric heating solutions that are attractive in design, as well as powerful in performance. The heaters range from fan-forced to infrared and are suited to different spaces requirements. Dimplex electric fireplaces lead the industry with flame effect technology and realistic media bed accessories.

DM Select Services has proudly provided heating, cooling and plumbing services to clients all around the Northern Virginia (NOVA) area since 2009. We have physical offices located all over the NoVA area in Ashburn, Burke, Fairfax Station, Leesburg, and Winchester, so we can meet you wherever you are located. Our team brings a wealth of HVAC experience and is focused on delivering quick turnaround times on our installations at an affordable price.

dmg events is an international exhibition and publishing company with events across more than 25 countries in the Middle East, Europe, Africa, the Americas, and Asia. Headquartered in Dubai since 1989, it has expanded operations from this global hub city to Saudi Arabia, Singapore, Canada, South Africa, Egypt, and the UK, achieving impressive growth in emerging and mature markets.

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.

Doc’s Super Vac began in 1991 and takes pride in its work. They specialize in cleaning and restoration of residential to industrial ductwork.

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.

Donaldson Company helps solve some of the world's most complex filtration and contamination control challenges, and is one of the largest global providers of unique filtration technologies and high-quality filters and parts. Their filtration technologies and products are used every day, in a variety of industries and environments, including aerospace, agriculture, construction, manufacturing, mining, power generation, transportation, etc.

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.

Dongfang Electric Corporation (DEC) is a company based in Chengdu China, with businesses all over the world. With a long-term commitment to providing an integrated solution to global energy, transportation, environmental protection, and other infrastructure, they are determined to become top-notch energy and electromechanical equipment system integrator, service provider, engineering contractor, and overseas infrastructure investing.

Donnelly is the most reliable mechanical contractor in New York City. Donnelly gives the clients peace of mind. Donnelly does this by providing the most innovative services and solutions through the experienced team. New York City’s premier provider of HVAC service, maintenance, and construction, as well as energy solutions.

Donovan & Sons, Inc. provides a full range of plumbing, heating, ventilation and cooling services for both residential and commercial customers. The company is made up of 5th generation plumbers and HVAC technicians dedicated to providing their customers with prompt, reliable, professional services.

Dornan Engineering Ltd. offers a full range of Mechanical, Electrical, Instrumentation, HVAC and Commissioning Services that will take any project from the construction drawings right through to final handover and commissioning.

Dowdle Heating and Air has been serving North MS since 1952. In 2012, Chris Powell merged with Dowdle to create Dowdle and Powell Heating and Air. They are an HVAC contractor. They offer service, sales, installation and fabrication of all HVAC equipment including air conditioners, thermostats, heat pumps, air filters, gas furnaces, programmable thermostats, humidifiers, ductless split systems.

Dowling Corporation is a pioneer HVAC/R mechanical services provider serving clients in New Hampshire, Southern Maine, and the North Shore of Massachusetts. Providing comfort and peace of mind since 1961.

Safe-T-Flush by Drain Shield is the new standard for condensate drain management, preventing leaks and clogs by ensuring a natural flow of condensation out of the drain line. The Safe-T-Flush system eliminates repetitive service calls, improve air quality with the unit, and prevent extensive and costly property damage.

Drake Refrigeration, Inc. is one of the best industrial chiller manufacturers. design custom industrial process chillers to meet a customer's particular .

Drews Marine GmbH supplies the maritime industry with highly individual or standardized solutions in the areas of refrigeration, air conditioning, ventilation, heating, pipeline construction and automation.

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.

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.

Duct & Vent Cleaning of America, Inc. was founded in April of 1989 by Ron Eckman. As early as February of 1990, Duct & Vent Cleaning of America, Inc. joined NADCA, the HVAC Inspection, Maintenance and Restoration Association. In fact, they were the first company to be allowed membership that used portable hepa vacuums in the cleaning process.

Duct Care Inc. provide is providing Professional Duct Cleaning Service since 2008. They also provide Furnace Cleaning, AC Coils Cleaning, Dryer Vent Cleaning and Central Vacuum Cleaning services. Their Unique Duct Cleaning process allow them to meet or exceed NADCA Duct Cleaning Procedure guide lines. From using pressure guns to different snake agitating whips and tools, they aim to not only get the job done, but get the job done right.

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.

Ductworks provides professional commercial and residential air duct cleaning services throughout Colorado.

Dunster Heat is based in the South West and is a nationwide biomass supplier and installer of vigas wood burning boilers and Akvaterm accumulators. Their biomass systems are combined to form an efficient biomass central heating system.