NATE is a nonprofit certification organization for heating, ventilation, air conditioning and refrigeration (HVACR) technicians. They provide service and installation certifications in: air conditioning, air distribution, air-to-air heat pumps, gas furnaces, oil furnaces, hydronics gas, hydronics oil, light commercial refrigeration, commercial refrigeration, ground source heat pump loop installer, and HVAC efficiency analyst.

NADCA is an international association of over 1,200 companies that provide HVAC inspection, maintenance (i.e., cleaning) and restoration services. NADCA offers standards, specifications, specialized training and certification for industry professionals.

NAEIR is a national nonprofit organization that takes in donations of excess inventory and redistributes those goods to schools and nonprofit organization.

The National Association of Home Builders represents the largest network of craftsmen, innovators and problem solvers dedicated to building and enriching communities.

The National Board of Boiler and Pressure Vessel Inspectors was created in 1919 to promote greater safety to life and property through uniformity in the construction, installation, repair, maintenance, and inspection of pressure equipment.

National Center for Construction Education and Research (NCCER) is a not-for-profit education foundation created in 1996, as The National Center for Construction Education and Research. NCCER develops standardized construction and maintenance curriculum and assessments with portable credentials.

An ANSI-accredited Standards Developing Organization, the National Electrical Manufacturers Association (NEMA) gives members a competitive edge in today's rapidly changing marketplace by expanding market opportunities, acquiring exclusive business intelligence, removing market barriers, building supply chain connections, and harnessing innovation.

The National Environmental Balancing Bureau (NEBB) is the premier international association of Certified Firms that perform Building Systems Commissioning, Building Envelope Testing, Cleanroom Performance Testing, Fume Hood Testing, Retro-Commissioning and much more!

The National Ground Water Association represents groundwater industry professionals including contractors involved in geothermal heat pump drilling and system installation.

The Occupational Safety and Health Act of 1970 established NIOSH as a research agency focused on the study of worker safety and health, and empowering employers and workers to create safe and healthy workplaces. NIOSH is part of the U.S. Centers for Disease Control and Prevention, in the U.S. Department of Health and Human Services. It has the mandate to assure “every man and woman in the Nation is safe and in healthy working conditions.

The institute's mission is to serve the nation and the public interest by supporting advances in building science and technology to improve the built environment.

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.

The Norman Economic Development Coalition is dedicated to expanding the economic base of the Norman community, enhancing the earning opportunities of area residents by retaining and expanding existing businesses and industries, as well as attracting desirable new employers that are consistent with Norman's high quality of life.

Norman S. Wright provides customers with exceptional systems knowledge to meet all project requirements. They represent HVAC manufacturers worldwide, and their product lines support the latest energy, sustainability and comfort standards.

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.

NAIMA is a non-profit certification program for technicians in the heating, ventilation, air-conditioning, and refrigeration (HVACR) industry and the only test supported by the entire industry.

The North American Sustainable Refrigeration Council is shaping a more sustainable, climate-friendly future for supermarket refrigeration. The technology, best practices, and manpower exist to greatly reduce the impact that supermarket refrigeration has on the environment, but right now lots of hurdles stand in the way. NASRC is an environmental nonprofit committed to taking action to address those hurdles and educating its members and public.

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.

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.

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.

PHIUS (Passive House Institute US, Inc.) is an organization committed to making high-performance passive building the mainstream market standard. PHIUS+ buildings provide superior indoor air quality, resilience during power outages, and an extremely quiet, comfortable indoor environment.

The Perfect Technician Academy is a school for Heating, Ventilation, and Air Conditioning (HVAC), created out of the need for a fast-track training program that could develop students ready to perform at high levels entering the skilled trades industry. They are committed to training and preparing heating, ventilation and air conditioning (HVAC) technicians for successful careers.

The Plastic Pipe and Fittings Association (PPFA) is a North American trade association comprised of member companies that manufacture plastic piping, fittings and solvent cements for plumbing and related applications, or supply raw materials, ingredients or machinery for the manufacturing process.

Qolsys Inc is a pioneer residential and commercial security and smart-home manufacturer. They provide smart thermostat, video monitoring, energy management and home automation.

Quality Heating, Cooling, Plumbing & Electric has provided the residents of the Glenpool and Tulsa, Oklahoma communities with professional heating, cooling, plumbing and electric services since 2014. This locally owned and operated company offers friendly and experienced technicians, industry-leading products, and professional residential systems service. Quality’s employees are also actively involved in their community and committed.

The RPA is an international trade association comprised of individuals and companies dedicated to increasing the use of radiant heating and cooling technologies through education and the development of codes and standards language reflecting best practices. RPA manufacturing members produce the tubing, valves, heat sources, emitters and controls used in radiant floors. RPA engineers and architects design high efficiency radiant hydronic systems.

Rathe Associates offers services like applications, provide technical backup, and field support int he HVAC industry and deals with Commercial Boilers & Water Heaters, Hydronic Heating Accessories & Controls, Radiant Heating & Snow Melting, Commercial Radiation, Pumps & Circulators and Steam Specialties & Controls.

Reacond Associates is a company that works towards selling and partnering with huge HVAC brands and supports the success of their customers and manufacturers.

REEF is a non-profit community of corporate sustainability pioneers and industry partners using their collective expertise and buying power to accelerate action on super-polluting refrigerants, with a focus on HVAC applications.

The Refrigerating Engineers and Technicians Association (RETA) exists to enhance the professional development of industrial refrigeration operating and technical engineers through education and certification.