Heating, ventilation, and air conditioning

HVACheatingclimate controlheaterheating, ventilation and air conditioningair conditioningclimate-controlledheating and air conditioningheating and coolingenvironmental control
This article is about heating, ventilation, and air conditioning; HVAC may also stand for high-voltage alternating current.wikipedia
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Mechanical engineering

mechanical engineermechanicalmechanical engineers
HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics and heat transfer.
In addition to these core principles, mechanical engineers use tools such as computer-aided design (CAD), computer-aided manufacturing (CAM), and product life cycle management to design and analyze manufacturing plants, industrial equipment and machinery, heating and cooling systems, transport systems, aircraft, watercraft, robotics, medical devices, weapons, and others.

Natural ventilation

cross ventilationCross-ventilationnatural
Methods for ventilating a building may be divided into mechanical/forced and natural types.
Natural ventilation is the process of supplying air to and removing air from an indoor space without using mechanical systems.

Sick building syndrome

healthy buildinghealthy living environmentproblems
HVAC is an important part of residential structures such as single family homes, apartment buildings, hotels and senior living facilities, medium to large industrial and office buildings such as skyscrapers and hospitals, vehicles such as cars, trains, airplanes, ships and submarines, and in marine environments, where safe and healthy building conditions are regulated with respect to temperature and humidity, using fresh air from outdoors.
Sick building causes are frequently pinned down to flaws in the heating, ventilation, and air conditioning (HVAC) systems.

HVAC control system

Climate Controlclimate control systemcontrol system
In modern buildings, the design, installation, and control systems of these functions are integrated into one or more HVAC systems.
HVAC (Heating, Ventilation and Air Conditioning) equipment needs a control system to regulate the operation of a heating and/or air conditioning system.

Room air distribution

displacement ventilationUnderfloor air distribution
The means of air delivery and removal from spaces is known as room air distribution.
HVAC airflow in spaces generally can be classified by two different types: mixing (or dilution) and displacement.

Architectural engineering

Building engineeringarchitectural engineerarchitectural
For larger buildings, building service designers, mechanical engineers, or building services engineers analyze, design, and specify the HVAC systems.
Architectural engineering, also known as building engineering or architecture engineering, is an engineering discipline that deals with the technological aspects and multi-disciplinary approach to planning, design, construction and operation of buildings, such as analysis and integrated design of environmental systems (energy conservation, HVAC, plumbing, lighting, fire protection, acoustics, vertical and horizontal transportation), structural systems, behavior and properties of building components and materials, and construction management.

Central heating

central heating systemhome heatingheating
This can be done via central heating.
When combined with other systems in order to control the building climate, the whole system may be an HVAC (heating, ventilation and air conditioning) system.

Willis Carrier

Willis Haviland CarrierCarrierWillis H. Carrier
HVAC is based on inventions and discoveries made by Nikolay Lvov, Michael Faraday, Willis Carrier, Edwin Ruud, Reuben Trane, James Joule, William Rankine, Sadi Carnot, and many others.
In 1915, he founded Carrier Corporation, a company specializing in the manufacture and distribution of heating, ventilation, and air conditioning (HVAC) systems.

Nikolay Lvov

Nikolai Lvov
HVAC is based on inventions and discoveries made by Nikolay Lvov, Michael Faraday, Willis Carrier, Edwin Ruud, Reuben Trane, James Joule, William Rankine, Sadi Carnot, and many others.
He experimented with coal pyrolysis, proposed new uses for coal tar and sulphur, and wrote a reference book on heating and ventilation.

Heat pump

heat pumpsHeat Pumpingheat-pump
Such a system contains a boiler, furnace, or heat pump to heat water, steam, or air in a central location such as a furnace room in a home, or a mechanical room in a large building.
While air conditioners and freezers are familiar examples of heat pumps, the term "heat pump" is more general and applies to many heating, ventilating, and air conditioning (HVAC) devices used for space heating or space cooling.

Furnace

furnacesprocess heatgas furnace
Such a system contains a boiler, furnace, or heat pump to heat water, steam, or air in a central location such as a furnace room in a home, or a mechanical room in a large building.
In American English and Canadian English usage, the term furnace refers to the household heating systems based upon a central furnace, otherwise known either as a boiler, or a heater in British English.

Air handler

air handling unitair handlingAHU
Mechanical, or forced, ventilation is provided by an air handler (AHU) and used to control indoor air quality.
An air handler, or air handling unit (often abbreviated to AHU), is a device used to regulate and circulate air as part of a heating, ventilating, and air-conditioning (HVAC) system.

Free cooling

Basing HVAC on a larger network helps provide an economy of scale that is often not possible for individual buildings, for utilizing renewable energy sources such as solar heat, winter's cold, the cooling potential in some places of lakes or seawater for free cooling, and the enabling function of seasonal thermal energy storage.
In heating, ventilation, and air conditioning (HVAC) in winter months, large commercial buildings interior spaces may need cooling, even while perimeter spaces may need heating.

Refrigeration

refrigeratedcold storagecooling
"Refrigeration" is sometimes added to the field's abbreviation, as HVAC&R or HVACR or "ventilation" is dropped, as in HACR (as in the designation of HACR-rated circuit breakers).
It is also applied to heating, ventilation, and air conditioning HVACR work, when describing the "process" of refrigerant flow through an HVACR unit, whether it is a packaged or split system.

Mechanical room

boiler roomboiler houseplant room
Such a system contains a boiler, furnace, or heat pump to heat water, steam, or air in a central location such as a furnace room in a home, or a mechanical room in a large building.
Modern buildings use control systems to manage HVAC cycles, lighting, communications, and life safety equipment.

Air conditioning

air conditionerair-conditionedair-conditioning
Air conditioning systems are used, either as backups or supplements.
In construction, a complete system of heating, ventilation, and air conditioning is referred to as HVAC.

Heat transfer

heat flowheatheat exchange
HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics and heat transfer.
Heat transfer methods are used in numerous disciplines, such as automotive engineering, thermal management of electronic devices and systems, climate control, insulation, materials processing, and power station engineering.

Fan (machine)

fanfanselectric fan
Ceiling fans and table/floor fans circulate air within a room for the purpose of reducing the perceived temperature by increasing evaporation of perspiration on the skin of the occupants.
Typical applications include climate control and personal thermal comfort (e.g., an electric table or floor fan), vehicle engine cooling systems (e.g., in front of a radiator), machinery cooling systems (e.g., inside computers and audio power amplifiers), ventilation, fume extraction, winnowing (e.g., separating chaff of cereal grains), removing dust (e.g. sucking as in a vacuum cleaner), drying (usually in combination with a heat source) and to provide draft for a fire.

Economizer

economiserexhaust gas economizerair-side economizer
Air-side economizers also use outside air to condition spaces, but do so using fans, ducts, dampers, and control systems to introduce and distribute cool outdoor air when appropriate.
Boiler, power plant, heating, refrigeration, ventilating, and air conditioning (HVAC) uses are discussed in this article.

Fuel

fuelsenergy-richFuel type
Heaters exist for various types of fuel, including solid fuels, liquids, and gases.
Solid fuel refers to various types of solid material that are used as fuel to produce energy and provide heating, usually released through combustion.

Skyscraper

skyscraperssupertallsupertall skyscraper
HVAC is an important part of residential structures such as single family homes, apartment buildings, hotels and senior living facilities, medium to large industrial and office buildings such as skyscrapers and hospitals, vehicles such as cars, trains, airplanes, ships and submarines, and in marine environments, where safe and healthy building conditions are regulated with respect to temperature and humidity, using fresh air from outdoors.
Furthermore, a skyscraper consumes a lot of electricity because potable and non-potable water has to be pumped to the highest occupied floors, skyscrapers are usually designed to be mechanically ventilated, elevators are generally used instead of stairs, and natural lighting cannot be utilized in rooms far from the windows and the windowless spaces such as elevators, bathrooms and stairwells.

Hydronics

hydronichydronic heatinghydronic heating systems
The use of water as the heat transfer medium is known as hydronics.
A recent innovation is the chiller boiler system, which provides an efficient form of HVAC for homes and smaller commercial spaces.

Boiler

boilerssteam generatortop feed
Such a system contains a boiler, furnace, or heat pump to heat water, steam, or air in a central location such as a furnace room in a home, or a mechanical room in a large building.
Saturated steam is useful for many purposes, such as cooking, heating and sanitation, but is not desirable when steam is expected to convey energy to machinery, such as a ship's propulsion system or the "motion" of a steam locomotive.

Forecasting (heating)

Forecasting
Forecasting is another method of controlling building heating by calculating demand for heating energy that should be supplied to the building in each time unit.
Forecasting is a method of controlling building heating by calculating demand for heating energy that should be supplied to the building in each time unit.

Water heating

water heaterhot waterwater heaters
Most modern hot water boiler heating systems have a circulator, which is a pump, to move hot water through the distribution system (as opposed to older gravity-fed systems).
Most potable water heaters in North America are completely separate from the space heating units, due to the popularity of HVAC/forced air systems in North America.