Nortek Global HVAC designs and manufactures reliable heating and cooling products. Nortek Global HVAC and its subsidiaries build and sell HVAC systems under the Maytag, Frigidaire, Gibson and Reznor brands, among others.

The North American Electric Reliability Corporation (NERC) is a not-for-profit international regulatory authority whose mission is to assure the reliability and security of the bulk power system in North America. NERC develops and enforces Reliability Standards; annually assesses seasonal and long‐term reliability; monitors the bulk power system through system awareness; and educates, trains, and certifies industry personnel.

Based out of Minnesota, USA, Northern's One Hour Heating & Air Conditioning provides solutions like Air Conditioning, Heating, Furnaces, Air Quality and other HVAC services.

NTT Training is about delivering very practical hands-on safety and trade skills to workers around the world. They deliver the most comprehensive, skills-based HVAC training programs and Hands-On Training.

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.

NUPI AMERICAS, INC. was founded in 2001. It is located in Houston, TX where it established a warehouse and production facility. Another warehouse and operations centre is located in Early Branch, SC. NUPI Americas is responsible for sales and marketing activities for the Americas and now also has 2 production lines. It also expanded the use of multilayer technology to the upstream market developing a specific product for flow line applications.

nVent RAYCHEM is a provider of heat-trace management systems for infrastructure, industrial, commercial and residential buildings, with operations globally. They help customers enhance productivity and reduce their costs by simplifying installation and minimize downtime during operation.

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.

Octopus Energy drives system change: with transformative tech to make renewable energy the norm and end global reliance on fossil fuels. Octopus Energy Group is made up of 10 businesses spanning 6 countries across 3 continents, including: Octopus Energy Retail, Kraken Technologies, Octopus Energy Generation, Kraken Flex, Octopus Electric Vehicles, and the Octopus Centre for Net Zero.

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.

A family owned business, Olson Comfort Services takes pride in offering the highest quality heating and cooling services. They are licensed, bonded, and insured.

Omdia unifies and harnesses the depth and breadth of expertise from Informa Tech’s legacy research brands: Ovum, IHS Markit Technology, Tractica and Heavy Reading. They offer unparalleled, world-class research and consultancy to navigate the now and create the future.

OMNIA Partners, Public Sector is the cooperative purchasing organization that is driving excellence in public sector procurement for K–12 schools and districts, state and local governments, colleges and universities and nonprofits. OMNIA Partners offers the most robust portfolio of high-quality cooperative contracts in the public procurement space.

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 provides a wide range of HVAC services, including installation, maintenance and repair of air Conditioning Units, Heating, Furnaces, Air Quality, Thermostats, etc and is based out of USA.

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 Hour Heating & Air Conditioning of Lake Villa provides home owners throughout the Round Lake region with reliable and efficient HVAC services and solutions.

One Source, Inc. provides complete building management services for commercial properties throughout San Diego. they work with clients in a wide variety of industries to coordinate services in every area of maintenance, from janitorial services to landscaping, high-pressure washing, carpet cleaning, window washing, junk removal, and much more.

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.

Oozzio offers an one-stop-shop for HVAC supplies! Whether for appliance repair, HVAC business, or a DIY enthusiast, Oozzio has everyone covered. Discover top brands, heating, cooling systems, furnaces, mini splits, air conditioners & accessories at their stores. Their user-friendly website and powerful search tools are the most trusted source for residential & commercial HVAC equipment.

OpenTherm is a non-manufacturer-dependent system of communication between modulating HVAC appliances and room thermostats. It consists of a communication protocol and an interface specification. The OpenTherm communication protocol is primarily designed to control modulating heating appliances. The protocol is available to members of the OpenTherm Association only.

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.

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.

Ouellet is the manufacturer of heating and ventilation equipment for institutional, commercial, industrial and residential applications; electric heating equipment to include unit heaters, ceiling heaters, cabinet heaters, baseboard, bath ventilation, Heating Cable, Self-Regulating Cable etc.

Owen AC Services specialize in providing HVAC services, as well as air quality services. They work with air conditioners, providing installations, repairs, and maintenance, as well as heaters. They work with folks throughout Houston and the surrounding area, and they strive to ensure that home is comfortable, and its air remains fresh and healthy.

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.