ONDA S.p.A. is manufacturing company of advanced heat exchangers for refrigeration, heating and air conditioning equipment.

One Call Heating and Cool is a Georgia-based Air Conditioning, Heating, HVAC and Air Purification systems installation and services company.

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.

ONICON Incorporated has been delivering market leading flow and energy measurement products since 1987. Their inventory includes hydronic insertion turbine flow meters, hydronic inline turbine flow meters, BTU meters, flow computers, vortex flow meters, electromagnetic flow meters. They have been delivering quality engineered flow and energy measurement instruments for hydronic heating and cooling systems for over 30 years.

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.

Opera Electronics Inc. develops and manufactures a range of indoor air quality and gas sensors for buildings. The core applications of the company are vehicle emissions monitoring in car parks, refrigeration gas leak detection, and combustible gas monitoring in HVAC plant rooms.

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.

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.

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.

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.

Owens Companies brings over six decades of experience to each building they service. They are the leading fully integrated, single-source mechanical contractor in the Twin Cities. Twenty-four hours per day, seven days per week, Owens is here for home or business.

Pacific Air Conditioning & Sheet Metal, LLC is Maui's leading Air conditioning repair contractor. They pride themselves on offering the best quality possible to service both commercial and residential air conditioning for customers alike; they will continuously strive to exceed all of expectations. The main goal of the company is to create a lasting impression on all its customers. They believe that the way in which they treat their customers.

Pacific Coast Heating and Air has been serving the San Fernando Valley Santa Clarita and Ventura County area since 1995. They are dedicated to meeting their customer’s heating and air conditioning repair needs. Their focus on customer service can be seen in the positive reviews the company has received over the years.

Pacific NW Reps, LLC is a progressive manufacturers representative firm in the Pacific Northwest representing HVACR manufacturers in Alaska, Arizona, Idaho, Montana, Nevada, New Mexico, Oregon, Washington, Utah & Western Canada.

Pacifica Home Services Ltd. provide a wide range of HVAC and home improvement services in the region of Houghton Le Spring, in Sunderland, in the United Kingdom.

Pack HVAC are dedicated to provide top-notch heating, ventilation, and air conditioning (HVAC) solutions to ensure optimal comfort and air quality for homes and businesses. Their skilled team specializes in a full range of services, from routine maintenance and quick repairs to new installations and system upgrades. They understand that each home and business has unique cooling needs, which is why they offer customized solutions.

Pack HVAC services has been customer's solution for heating and cooling issues in the Baton Rouge area for over 15 years! Their licensed and bonded team repairs, installs, and services all major brands of HVAC systems including heat pumps, furnaces, air conditioners, thermostats, air handlers, and high efficiency units.

Packerland Heating & Cooling provides heating and cooling services and is based out of the USA.

Palatine Heating & Cooling Company offers quality service in Palatine and the surrounding suburbs. They provide installation, repairs and maintenance services.

When it comes to heating & cooling for home or office, Palatine Unique Indoor Comfort provides expert HVAC installation & repair services in Palatine & nearby areas of the US state of Illinois.

Pallardy Heating & Air Conditioning is dedicated to providing the best possible solution for home or business. One can count on them to provide you with a system and solution that fits one's unique needs.

Panasonic is the premier manufacturer of powerful, energy-efficient ventilation fans and indoor air quality solutions. We produce the highest quality, code compliant solutions available in the market today.

Parker Heating & Cooling is a family-owned and operated heating and cooling company. Their heating and cooling technicians are experienced educated technicians and installers.

Parthenon Plumbing is Middle Tennessee’s premier, full-service plumbing company. Headquartered in Nashville, TN, they specialize in commercial and residential plumbing.

The Passive House Institute (PHI) is an independent research institute that has played an especially crucial role in the development of the Passive House concept - the only internationally recognized, performance-based energy standard in construction.

PassiveLogic is disrupting the world of automation with the first fully autonomous platform for buildings. They reinvented automation to replace legacy control logic with real-time control decisions at the edge, reducing the world's carbon footprint, while paving the way for smart cities.