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.

Oversluizen distinguishes itself by developing and producing cooling solutions for the industry 1-on-1 with the client. In their own factory in Ridderkerk they calculate and produce the coolers for the project in-house.

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.

The Danish-based company was founded in 1988. Pioneering developer and manufacturer of research manikin systems, including thermal manikins, sweating manikins, and breathing manikins - ideal for evaluating the thermal comfort of HVAC systems, clothing & protective equipment, vehicle cabins and indoor environments in general.

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.

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.

Palmer Instruments are the manufacturers of custom-engineered RTDs and thermocouple sensors, thermowells, industrial digital, bimetal, infrared and dial thermometers, chart recorders, temperature recording labels, RTD and thermocouple meters.

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.

Paradise provides heating and cooling solutions and is based out of the USA.

At Parasense, they provide food retail, military, nuclear and industrial sectors with innovative and cost effective refrigerant management, energy management, systems integration and performance management solutions.

Paschal has provided professional Heating & Air, Plumbing & Electrical services to homeowners & businesses in Arkansas, Texas, Oklahoma, Kansas & Missouri. They provide air conditioner repair and replacement services, water heater installation, generator sales & service, & more.

Paschal Heat, Air & Geothermal, the team of trained and certified HVAC technicians in Northwest provides timely, friendly support, and they guarantee 100% satisfaction from start to completion.

Passiv UK is an energy technology business with over a decade of experience developing smart solutions to decarbonize homes. The Passiv Smart Thermostat is a first-of-its-kind thermostat that makes heat pumps simple, and affordable, and can unlock additional value from the provision of Demand Side Response (DSR).

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.

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.

Patterson-Kelley serves the commercial heating industry with the most respected products in the field. They provide Commercial Boilers, Commercial Water Heaters, Fabricated Systems, Commercial Solutions, Heating Solutions, Engineeering Solutions and much more.

PCE Instruments are the manufacturer and supplier of test devices, control systems, lab equipment, scales and balances. They have headquarters in Germany and sales offices around the world, including UK and US.

Air Conditioning in London. Residential and commercial Air Conditioning Installers with 30 Years of Experience in London & Kent. Air Conditioning Installation Contractors - Finance & 5-Year Warranty Available.

Peak Heating & Cooling Inc. specializes in the repair and replacement of the heating and cooling systems for the home or business. Peak Heating & Cooling Inc. will send only the best technician to fix the plumbing problem, air conditioner repair and, gas or propane (LP) furnace and heater repair as well as the air conditioner installation, furnace, boiler replacement, and tankless hot water heaters installation.

Peck & Weis provides the best full service HVAC, plumbing, and electrical contractor services to customers. Their award-winning team offers the highest quality products and service to ensure customers home or business runs smoothly and safely.

Pelion was originally founded as an incubation unit within Arm, the designer of key technologies at the heart of computing. With a unique combination of global IoT connectivity and device management from a single vendor, Pelion breaks down barriers to IoT adoption for anyone looking to transform their industry.

Perdido Heating and Air Conditioning cater to all air conditioning and heating needs. They service and repair their customers with excellence. They do sales, service, and installation and make sure their customers feel good at home or business. They also provide estimates on new installations.

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.