Nu-Air designs and manufactures high quality heat recovery ventilators (HRV's), energy recovery ventilators (ERV's), air handlers and vertical fan coils with integrated H/ERVs. Their primary markets are commercial, residential, multi-unit residential and institutional.

Nu-Calgon markets and distributes a complete line of specialty chemical products for the HVACR aftermarket. They provide water treatment, sealants, specialty and service chemicals, coil cleaners, system flush solvents, refrigeration oil, vacuum pump oil, ice machine treatment, indoor air quality.

Nu-Mun Contracting is a Calgary based plumbing company formed by Doug Muncaster in 1989. They provide sheet metal installations for commercial, industrial and residential applications. The company also offers air conditioning, residential plumbing, commercial plumbing, and other HVAC solutions.

Founded in 1966, Nuaire is an indoor air quality and ventilation manufacturing specialist, with multi-award-winning ventilation systems that are used in a wide range of commercial and residential applications, including hotels, houses, stadiums, museums, and healthcare services.

NuComfort is a Chicago-based wholesale distributor of residential and commercial heating and cooling systems, as well as replacement parts, indoor air quality products and home generators. They have been in business since 2002.

Nuvolo is the pioneer in modern, cloud-based Connected Workplace solutions. They provide a single platform to manage all people, all physical locations, all assets, and all work – enabling data sharing across departments.

Nyle Systems is a manufacturer of commercial energy-efficient heat pump water heating systems.

O.T. Hall & Son has been successfully promoting electrical, lighting, heating and networking products since 1920. They are family-owned and operated and service Maryland, DC, Virginia, Delaware and the panhandle of West Virginia.

Oakes Energy Services Ltd (Oakes Energy) designs and installs both commercial and domestic renewable energy systems. In turn, dramatically reducing the cost of energy consumption and enabling the business or home to save thousands of pounds on their energy bills. Oakes Energy Services Limited was established in 2007 with the aim of offering customers an alternative, more sustainable approach to their energy needs.

Oakwood Homes, a Berkshire Hathaway company, has always built, sourced and stayed true to what's local. By leveraging resources and partners right here at home, they can deliver true luxury in homes at every price point - for people in every stage of life.

With the Occupational Safety and Health Act of 1970, Congress created the Occupational Safety and Health Administration (OSHA) to ensure safe and healthful working conditions for workers by setting and enforcing standards and by providing training, outreach, education and assistance. The OSH Act covers most private sector employers and their workers, in addition to some public sector employers and workers in the 50 states and certain territories.

For more than half a century, OJ Electronics have been designing and developing electronic controls for electric underfloor heating and HVAC Controls & Drives. They give access to deep application knowledge and innovative power and help differentiate themselves in the market. They are here to help build their customers’ business.

OklahomaGroup offers premier sales representation to all sectors of the HVAC and Refrigeration markets throughout the state of Oklahoma. Account Managers are dedicated to customer's needs and are supported by market and sales specialists.

OMS Machinery Co.,Ltd. is a High-Tech company, dedicated to the development and production of automatization, digitalization, and intelligentization equipment. Located in Zhongshan, Guangdong, OMS employs 80 professional engineers, and is well equipped with facilities. The company’s quality system and measurement system are ISO certified.

On Air services the South Palm Beach County areas, Broward County and North Dade County.We install and service all major and minor brand air conditioners, serving both Residential and Commercial Customers.

One Hour Heating & Air Conditioning® of Lee's Summit is the most trusted source of HVAC services in the Lee’s Summit area. Their team of Lee's Summit heating and cooling technicians are highly trained and licensed, so that they can provide the best Lee’s Summit HVAC repairs, installation, and maintenance possible.

One Source Home Service, an Air Pros company, was founded on the premise of Integrity, Reliability, and putting the customers first. One Source Home Service is here to help the users with HVAC, ductwork, plumbing, electrical, and home energy needs in the Colorado Springs and Pueblo, CO areas.

Onset HOBO data loggers provide reliable, accurate data in energy monitoring applications, including HVAC systems monitoring, building energy audits, measurement and verification, and building commissioning.

Optimum Energy’s patented software and engineering expertise has helped customers reduce energy use in heating and cooling systems, the largest consumer of energy in buildings, by up to 50%. Their solutions combine technologically advanced HVAC optimization software with powerful cloud-based data analytics and world-class engineering support.

Ordine's Air Conditioning And Heating Inc. stands out in the heart of Tampa Bay, Florida, as a distinguished family-owned and -operated AC company with a rich heritage spanning over 30 years and three generations. They pride themselves on their reliability, expertise, and customer-focused service, ensuring customers' heating, ventilation, and air conditioning needs are met with the highest standards.

Orival has supplied thousands of filtration units for a wide variety of customers, including Fortune 500 companies, farms, local municipalities, federal government agencies, and many more. Orival automatic self-cleaning filters are proven effective in filtration or recirculating and once through cooling water and chilled water in HVAC systems.

Orell Filtration is based in Stalybridge and supplies Dust Extraction Equipment, Bulk Bags, Air Filters, Filtration Products, Filter Fabrics, Filter Sleeve Bags, Multipockets, and much more.

Over 25 years ago, Victor Orzech began an HVAC company out of a basement workshop in his home. The years have brought many changes, but one thing remains the same: a commitment to the highest level of service and installation in the HVAC industry.

As a full service Air Conditioning, Heating and Ventilation company, OSBORN AC and Heat has been delivering high standard HVAC services.

Oventrop is one of the European manufacturers of valves and controls for the Building Services Industry. The company is an expert partner to stockists, consultants, contractors, and industry. Oventrop offers its partners a long-term beneficial relationship.

Over represents what every innovative company must be: Over and Above. Following this concept, it is set to establish a global standard for energy management and indoor air quality to make cities healthier, smarter, and more efficient. Over aim to be a pivotal resource with a collective effort to combat environmental issues mainly climate change and achieve energy efficiency within the UN Sustainable Development Goals.

Oxygen8 is changing the way buildings provide healthy, comfortable and energy efficient spaces for occupants. They provide 100% fresh, filtered air and smart technology for maximum comfort and value.

P & R Heating provides a wide range of installation and servicing such as mechanical installation, plant room renewals, heating installation (large and small scale), hot and cold water storage and distribution, plant control installations, gas and oil servicing and maintenance, periodic test and inspection, emergency lighting and much more.

PED Associates Inc. is a manufacturers’ representative company serving HVAC/R, appliance parts, wholesale distributor, OEM’s and exporters.

Pace Heating and Air - Albany service all makes and models of furnaces and air conditioners. And they proudly offer the full line of Carrier heating and cooling equipment, as well as hearth products from HEAT-N-GLO.