Heating, ventilation, and air conditioning (HVAC) is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer. "Refrigeration" is sometimes added to the field's abbreviation as HVAC&R or HVACR, or "ventilation" is dropped, as in HACR.
A fume hood is a type of local ventilation device that is designed to limit exposure to hazardous or toxic fumes, vapors or dusts.
Vans is an American manufacturer of skateboarding shoes and related apparel, started in Anaheim, California, and owned by VF Corporation. The company also sponsors surf, snowboarding, BMX, and motocross teams. From 1996 to 2019, the company has been the primary sponsor of the annual Vans Warped Tour traveling rock festival.
An air handler, or air handling unit, is a device used to regulate and circulate air as part of a heating, ventilating, and air-conditioning (HVAC) system. An air handler is usually a large metal box containing a blower, heating or cooling elements, filter racks or chambers, sound attenuators, and dampers. Air handlers usually connect to a ductwork ventilation system that distributes the conditioned air through the building and returns it to the AHU. Sometimes AHUs discharge (supply) and admit (return) air directly to and from the space served without ductwork
Tomkins plc was a multinational engineering company headquartered in London, United Kingdom. In July 2010 Tomkins was acquired by a Canadian consortium of private equity firm Onex Corporation and the Canada Pension Plan Investment Board. In July 2014, The Blackstone Group, the world's largest buyout firm, agreed to acquire The Gates Corporation, the largest division of Tomkins plc from Onex Corp. (OCX) and Canada Pension Plan Investment Board for $5.4 billion.
A diffuser is "a device for reducing the velocity and increasing the static pressure of a fluid passing through a system”. The fluid's static pressure rise as it passes through a duct is commonly referred to as pressure recovery. In contrast, a nozzle is used to increase the discharge velocity and lower the pressure of a fluid passing through it.
Ducts are conduits or passages used in heating, ventilation, and air conditioning (HVAC) to deliver and remove air. The needed airflows include, for example, supply air, return air, and exhaust air. Ducts commonly also deliver ventilation air as part of the supply air. As such, air ducts are one method of ensuring acceptable indoor air quality as well as thermal comfort.
Room air distribution is characterizing how air is introduced to, flows through, and is removed from spaces. HVAC airflow in spaces generally can be classified by two different types: mixing and displacement.
A fan is a powered machine used to create a flow of air. A fan consists of a rotating arrangement of vanes or blades, generally made of wood, plastic, or metal, which act on the air. The rotating assembly of blades and hub is known as an impeller, rotor, or runner. Usually, it is contained within some form of housing, or case. This may direct the airflow, or increase safety by preventing objects from contacting the fan blades. Most fans are powered by electric motors, but other sources of power may be used, including hydraulic motors, handcranks, and internal combustion engines.
Fire dampers are passive fire protection products used in heating, ventilation, and air conditioning (HVAC) ducts to prevent the spread of fire inside the ductwork through fire-resistance rated walls and floors. Fire/smoke dampers are similar to fire dampers in fire resistance rating, and also prevent the spread of smoke inside the ducts. When a rise in temperature occurs, the fire damper closes, usually activated by a thermal element which melts at temperatures higher than ambient but low enough to indicate the presence of a fire, allowing springs to close the damper blades. Fire dampers can also close following receipt of an electrical signal from a fire alarm system utilising detectors remote from the damper, indicating the sensing of heat or smoke in the building occupied spaces or in the HVAC duct system.
HVAC is a major sub discipline of mechanical engineering. The goal of HVAC design is to balance indoor environmental comfort with other factors such as installation cost, ease of maintenance, and energy efficiency. The discipline of HVAC includes a large number of specialized terms and acronyms, many of which are summarized in this glossary.
Solar air heating is a solar thermal technology in which the energy from the sun, insolation, is captured by an absorbing medium and used to heat air. Solar air heating is a renewable energy heating technology used to heat or condition air for buildings or process heat applications. It is typically the most cost-effective out of all the solar technologies, especially in commercial and industrial applications, and it addresses the largest usage of building energy in heating climates, which is space heating and industrial process heating.
Watsco, Inc. is the largest distributor of air conditioning, heating and refrigeration equipment, and related parts and supplies (HVAC/R) in the United States. Watsco was founded more than 60 years ago as a manufacturer of parts, components and tools used in the HVAC/R industry. From 1973 to 1988 Watsco under the leadership of its current CEO, Albert H. Nahmad, grew from US$5 million in revenues to US$25 million. In 1989, the company shifted its focus from manufacturing to distribution by acquiring Gemaire Distributors Inc., a South Florida-based Rheem distributor. By 1997, Watsco added other OEMs to the mix and moved into commercial refrigeration as a result of the acquisition of Baker Distributing Company. Watsco divested its manufacturing business in 1998, selling it to International Comfort Products Corporation, now part of Carrier Corporation (Carrier). Revenues increased from US$64.1 million in 1989 to US$5.1 billion in 2020 via a strategy of acquiring companies with established market position and subsequently building revenues and profit through a combination of adding locations, products, services and other initiatives.
Goodman Manufacturing is an American company operating as an independent subsidiary of Daikin Group, the world's largest manufacturer of heating, ventilation and air conditioning products and systems. The company, founded in 1975 and based in Houston, Texas, manufactures residential heating and cooling systems.
SPX Corporation is a supplier of highly engineered infrastructure equipment and technologies. The company operates within four markets: heating, ventilation, and air conditioning (HVAC), detection and measurement, power transmission and generation, and engineered solutions. Examples of SPX’s products include cooling towers and boilers, underground pipe and cable locators, power transformers, and heat exchangers. Brands include Waukesha, Dielectric, Fahrenheat, Radiodetection, and Pearpoint. SPX operates in 17 countries with a sales presence in 100 countries. In 2019, the company earned approximately $1.5 billion in annual revenue. Based in Charlotte, North Carolina, SPX employs over 6,000 employees. Eugene Joseph Lowe is the CEO.
Underfloor air distribution (UFAD) is an air distribution strategy for providing ventilation and space conditioning in buildings as part of the design of a HVAC system. UFAD systems use an underfloor supply plenum located between the structural concrete slab and a raised floor system to supply conditioned air through floor diffusers directly into the occupied zone of the building. UFAD systems are similar to conventional overhead systems (OH) in terms of the types of equipment used at the cooling and heating plants and primary air-handling units (AHU). Key differences include the use of an underfloor air supply plenum, warmer supply air temperatures, localized air distribution and thermal stratification. Thermal stratification is one of the featured characteristics of UFAD systems, which allows higher thermostat setpoints compared to the traditional overhead systems (OH). UFAD cooling load profile is different from a traditional OH system due to the impact of raised floor, particularly UFAD may have a higher peak cooling load than that of OH systems. This is because heat is gained from building penetrations and gaps within the structure itself. UFAD has several potential advantages over traditional overhead systems, including layout flexibility, improved thermal comfort and ventilation efficiency, reduced energy use in suitable climates and life-cycle costs. UFAD is often used in office buildings, particularly highly-reconfigurable and open plan offices where raised floors are desirable for cable management. UFAD is appropriate for a number of different building types including commercials, schools, churches, airports, museums, libraries etc. Notable buildings using UFAD system in North America include The New York Times Building, Bank of America Tower and San Francisco Federal Building. Careful considerations need to be made in the construction phase of UFAD systems to ensure a well-sealed plenum to avoid air leakage in UFAD supply plenums.
A dedicated outdoor air system (DOAS) is a type of heating, ventilation and air-conditioning (HVAC) system that consists of two parallel systems: a dedicated system for delivering outdoor air ventilation that handles both the latent and sensible loads of conditioning the ventilation air, and a parallel system to handle the loads generated by indoor/process sources and those that pass through the building enclosure.
Daikin Industries, Ltd. is a Japanese multinational air conditioning manufacturing company headquartered in Osaka. It has operations in Japan, China, Australia, United States, India, Southeast Asia, Europe, Middle East, Latin America, and Africa.
The Uniform Mechanical Code (UMC) is a model code developed by the International Association of Plumbing and Mechanical Officials (IAPMO) to govern the installation, inspection and maintenance of HVAC and refrigeration systems. It is designated as an American National Standard.
Vornado is an American firm based in Andover, Kansas, that designs and manufactures household fans and other small appliances related to air circulation. The current incarnation of the company was founded in 1989, two years after the death of Ralph K. Odor (1895-1987), who founded the firm in the 1930s with Ottis A. Sutton in Wichita, Kansas. The name of the company is a portmanteau of "Vortex" and "Tornado".
