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.

Organic Heat Exchangers (O-Hx) is the home of the patented 'EnergiVault' technology, capable of storing and delivering vast amounts of thermal energy on demand to drive down the cost of cooling and provide infinitely scalable energy storage.

Packard is a master distributor of over thirty brands of HVACR solutions and is dedicated to providing the best service, selection and satisfaction to wholesalers.

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.

Panasonic is a manufacturer of versatile heating and cooling solutions including single-split systems, multi-split systems, ECOi VRF-systems, controls and accessories.

Parker Boiler is the manufacturer of Industrial steam boilers, hot water boilers (direct, indirect and condensing), high-temperature liquid heaters, water heaters, tanks and heat exchangers.

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).

Patriot IAQ products improve indoor air quality throughout the home or office by cleaning the air as it passes through the central air (HVAC) system. Patriot IAQ products also improve the efficiency and longevity of the air system by keeping it clean and free of mold.

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.

Established in 1940, Paul Mueller Company builds stainless steel processing equipment that cools, heats, and stores the products you use every day. They are the global supplier of heating, cooling and storage solutions that allow farmers, brewers and engineers to keep their products fresh and their inventory strong.

Payne offers residential HVAC products available over the counter at Totaline Sales Centers nationwide. Products include split system air conditioners and heat pumps, gas furnaces, evaporator and fan coils, ductless split systems and packaged products.

Through experience, technology and innovation, PB Heat, LLC continues to be a top manufacturer in the hydronic heating industry with the Peerless® brand. When it comes to installing a boiler system for your customers, you want to provide the best value. That value starts with a top-quality Peerless® boiler as the foundation.

Peerless Blowers is a vertically integrated manufacturer of fans and blowers used in commercial and industrial applications. They produce a wide variety of ventilation/air moving equipment that offers solid performance, smooth operation and excellent value.

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.

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.

‍Performance Heating is the best resource for industrial heating equipment and service. They provide a wide variety of thermal fluid heaters, steam boilers, water tube boilers, pressurized hot water heaters, heat recovery systems, and steam generators to the US & Canadian markets.

Peterman is a family-owned residential heating, cooling & plumbing company with offices in Indianapolis, Columbus, Muncie, Bloomington, and Lafayette, Indiana. It specializes in heating & cooling repair & installation, along with plumbing services, drains & sewers.

Philco provides heating and cooling products for residential and light commercial industries. They provide Air conditioners, gas furnaces, heat pumps, air handlers, air cleaners.

PHNIX NORTH AMERICA is an international enterprise committed to advancing affordable energy-efficient heat pump technology in order to save energy and protect the environment.

Phoenix Contact is a strong partner for creative solutions in the fields of connection technology, electronics, and automation on the path to a smart world. Phoenix Contact solutions are used wherever processes need to run automatically. This can be in industrial production facilities, in the field of renewable energies, in infrastructure, or for complex device connections.

Pilar Services, Inc. is a full-service mechanical contractor that specializes in installation, new construction, sales, service, and maintenance contracts for all sizes and types of air conditioning and refrigeration equipment.

Pinder Cooling & Heating was born to deliver unrivaled customer service combined with expert engineering knowledge and the highest quality products in air conditioning and cooling systems.

Pinnacle believes in the old-school business principles of trust, reliability, and quality and has assembled a portfolio of companies that operate with integrity and a community-focused mindset.

Plumhouse manufactures central heating chemicals, radiator controls, fire valves, pumps, central heating controls, thermostats, motorized valves and 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.

PM IMPIANTI was founded with the aim of building and installing pre-insulated aluminum, galvanized sheet or stainless steel ducts: experience and professionalism at the customer's service. Over time, they have also specialized in the design, installation and maintenance of split, mini-split and air conditioning systems

Polar Engineering loves engineering energy recovery and industrial refrigeration systems. Its team prides itself on taking the time to truly understand the wants, needs, and values of each of our clients. This allows to create client-focused solutions that delicately balance initial costs, operating costs, energy efficiency, and greenhouse gas reductions.

Polaria provides solutions like Dehumidifiers, Air Conditioners, HVAC solutions, etc and is based out of Italy.

Plate heat exchangers, deliver compact brazed plate heat exchangers, double-wall plate heat exchangers, semi-welded plate heat exchangers and automatic self cleaning filters/strainers. Their Bernoulli Filters are self-cleaning even in systems with raw cooling water.