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.

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.

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.

Overly Hautz Motor Base manufactures and designs the world's most complete line of motor mounting products. They also provide Adjustable motor bases, conversion bases, pivoting and automatic motor bases.

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.

PJ Dionne Company serves the commercial plumbing and HVAC needs of public and private organizations across the greater Boston area. For a quarter century, the company's plumbers and pipe fitters have installed and maintained mechanical systems in new and historic buildings, working closely with the area’s leading general contractors, engineers, and building owners.

Packless Industries is a manufacturer of heat transfer and other metal hose products. They provide metal hose assemblies; vibration absorbers; refrigerant heat exchangers; co-axial condensers, evaporators (chillers) and heat pump coils; desuperheaters/heat reclaimers.

Parker Hannifin Corp. provides system protectors, valves and controls for industrial, supermarket, appliance, commercial, residential and mobile air conditioning and refrigeration applications. They provide Signature brands include Sporlan, R/S, HERL, Micro Thermo Technologies.

Perfect Temp Heating and Cooling is one of the best HVAC contractors in Minneapolis, MN, USA. At Perfect Temp, their commitment is to provide customers with the best possible service experience goes beyond just honoring a warranty or showing up when called upon.

Phoenix ACR Limited specializes in all aspects of Air Conditioning and Refrigeration for both the commercial and residential sectors throughout the South East including London. They work closely with their clients to ensure their needs are always met and that satisfaction is the end result. Their technicians specialize in the installation, maintenance, and repair of high-quality, energy-efficient air conditioning and refrigeration systems.

Pickrel Brothers is one of the Midwest's providers of pipe, valves, fittings, plumbing, heating and industrial supplies. They also provide boilers and hydronic equipment, heating and cooling coils, unit heaters, water softners, plumbing fixtures and much more.

Plumbing Medic is ready to help with any type of heating and air conditioning job in Gilbert. They’re also able to offer comprehensive plumbing services throughout Maricopa County.

Pottorff delivers quality HVAC products at competitive prices. They provide Smoke dampers, fire dampers, combo fire/smoke dampers, louvers, control dampers, access doors, ceiling dampers, motors and actuators and much more.

Powerbox International is a supplier of consumer products for the construction, DIY, and outdoor improvement industries. As a quality-centric manufacturer, it is constantly researching new and innovative product developments, adding genuine value for the customers.

As Temecula Valley’s most dependable and professional HVAC contractor, ProFlo Air Conditioning, Heating & Plumbing strive to keep their reputation in tact. They hold themselves and their work to the highest standard. Their technicians are constantly improving their skill set by frequently completing required training by their heating and air conditioning appliance suppliers.

Established in 2019, Propel Air Fans is built upon the core belief that keeping cool should not be a luxury that is unaffordable. Propel Air sets a goal to make a product that improves the lives of those without proper airflow. Propel Air's purpose is to ensure that a desired space is a place that is cool and enjoyable. The company offers two large industrial fans, the Model 1 and the Model 2, for commercial use.

Propous is one of the largest independent suppliers of gas and oil burner’s spare parts, valves, air heaters, and HVAC products. The success of the company can be attributed to its efficiency, reliability, technical knowledge and an understanding of the customer’s requirements.

Since 2019, ProThermal Heating and Cooling has served as the trusted HVAC contractor in Tulsa, OK, and nearby areas. Each technician on their team maintains certification and professional licenses. They consistently go above and beyond customer expectations, and they stand behind their work.

PTubes, Inc. is the US subsidiary of Feinroren S.p.A. - Italy. They are a renowned manufacturer of copper refrigeration coils, pipe and pre-insulated copper coils for the HVAC industry.

Pure Air Solutions is a family-owned HVAC business with over 20 years of experience, serving Thornton, Colorado, and nearby areas. They specialize in AC and furnace repair and installation, improving indoor air quality with reliable service and high-quality products. From immediate repairs to full installations, their knowledgeable team ensures top results.

Quality Heating & Air is an expert in HVAC services. They offer retro install estimate, air conditioning repair, heating and cooling services, or emergency heating and cooling repair. With over 15 years of knowledge and experience in the heating & cooling industry, they have all HVAC service needs covered. They are family-owned and operated HVAC contractor dedicated to providing comprehensive heating and cooling solutions.

R & Y A/C Compressor is the leader in A/C Auto Parts, providing quality car air conditioning parts & services. They manufacture & distribute variety of replacement mobile climate control products like compressors, driers/accumulators, evaporators, condensers and more.

Rack Engineering Division specializes in manufacturing storage and material handling products specifically designed for high weight capacities and heavy use. Rack Engineering understands that professional storage solutions are an integral element for efficiency and organization in the workplace, and they're proud to provide the highest quality products to the distributors and customers.

Randazzo Heating, Cooling, and Electrical is a Michigan-based company, keeping Michigan residents comfortable since 1988. They are committed to bringing their customers the best heating and cooling options. They are a company on a mission, focusing on offering their customers an optimum level of service!

Rapid Recovery provides refrigerant recovery services for the HVAC, refrigeration, demolition, and marine industries. Projects range in size from single residential split systems to chilling systems operating on tens of thousands of pounds, to projects with thousands of units.

Reclamation Technologies is the Midwest pioneer EPA certified refrigerant reclamation company. They offer a wide range of services to assist their customers with refrigerant management issues.

REFCOM is the UK's market F-GAS certification scheme, operating since 2009. They help companies make sure that they comply with F gas regulations since 2014.

RefPlus is a world-renowned manufacturer of refrigeration products. At the forefront of the latest technological innovations, their equipment combines performance and reliability.

Refrigeration Design Technologies (RDT) designs and manufactures refrigeration systems for food service operations. RDT has equipment in many restaurants, hotels, casinos, universities, hospitals, prisons, corporate dining facilities, sporting stadiums and theme parks.

With over 75 years of experience and 18 branches spanning across Western Canada, Refrigerative Supply Limited is now one of the country’s leading distributors of residential and commercial HVAC and refrigeration equipment, parts and tools. RSL continues to invest in providing its customers with fast, personable, and reliable service both in-store and online.