Return inlet (left)Supply outlet (right).

Ventilation is movement of air, typically between an indoor space and the outside. When people or animals are present, ventilation is especially necessary to evacuate the carbon dioxide produced and renew the oxygen used up. It is also needed to remove other pollutants (smoke, chemicals, etc.) from the space. Ventilation air can also be used to heat, cool, humidify and dehumidify the space and to filter particles or contaminants from the air. Image File history File links Download high resolution version (1024x672, 74 KB) Author Rafal Konkolewski 2005, relased under . File links The following pages link to this file: Ventilation ... Image File history File links Download high resolution version (1024x672, 74 KB) Author Rafal Konkolewski 2005, relased under . File links The following pages link to this file: Ventilation ... Look up air in Wiktionary, the free dictionary. ... Carbon dioxide is an atmospheric gas comprised of one carbon and two oxygen atoms. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ...

In office buildings and other standard applications, a percentage of the total air that is circulated is evacuated outside and compensated by outside air. The time it takes to completely turn over the air volume of a room is considered the ventilation rate and it is measured in air exchanges per hour. Inadequate ventilation in a space occupied by people can cause the level of carbon dioxide to increase leading to sleepyness.

If there is something burning (a fireplace, gas heater, candle, oil lamp, etc.) more oxygen is replaced by carbon dioxide (and possibly other poisonous gases and smoke) and more ventilation is needed. If there is a chimney then the additional need of ventilation just refers to replacing the warmer air that leaves by convection through the chimney with fresh air. Combustion or burning is a complex sequence of chemical reactions between a fuel and an oxidant accompanied by the production of heat or both heat and light in the form of either a glow or flames. ... A natural gas fireplace with a burning fire. ... A gas heater is a device used to heat a room by burning gas. ... A collection of lit candles on ornate candlesticks A close-up image of a candle showing the wick and the various regions of the flame. ... Antique bronze oil lamp with Christian symbol (replica) An oil lamp is a device used for lighting or for preserving a flame that is fueled by animal, vegetable or mineral oil. ... This article is about the dangerous substance. ... A gas is one of the four main phases of matter (after solid and liquid, and followed by plasma), that subsequently appear as a solid material is subjected to increasingly higher temperatures. ... Smoke from a wildfire Smoke is a suspension in air (aerosol) of small particles resulting from incomplete combustion of a fuel. ... A chimney is a system for venting hot gases and smoke from a boiler, stove, furnace or fireplace to the outside atmosphere. ... Convection is the transfer of heat by currents within a fluid. ...

Ventilation in a structure is also needed for removing water vapor, produced by breathing, burning, and cooking, and for removing smells, e.g. from a toilet or kitchen. If water vapor is permitted to accumulate, it may damage the insulation or interior finish. A dehumidifier may also be appropriate for removing moisture in the air. Water vapor or water vapour, also aqueous vapour, is the gas phase of water. ... For the play Breath by Samuel Beckett, see Breath (play). ... Cooking is an act of preparing food for eating. ... Boeing 747 toilet A toilet is a plumbing fixture and a disposal system primarily intended for the disposal of the bodily wastes; urine, fecal matter, vomit and menses. ... A kitchen is a room used for food preparation. ... Insulation must not be confused with insolation (the latter word has an o where the former has a u). Insulation is any material used to reduce or “slow down” or “resist” the flow of energy. ... A dehumidifier is a household appliance that reduces the level of humidity in a room. ...

Types of ventilation

• Natural ventilation: Natural ventilation occurs when the air in a space is changed with outdoor air without the use mechanical systems, such as a fan. Most often natural ventilation is assured though operable windows but it can also be achieved through temperature and pressure differences between spaces.
• Forced ventilation as in direct, dedicated or local exhaust ventilation
  • Fume hood
  • Biological safety cabinet
• Dilution ventilation as in general building or room ventilation
• Heat recovery ventilation

HVAC (pronounced either H-V-A-C or, occasionally, H-VAK) is an initialism/acronym that stands for heating, ventilation and air-conditioning. This is sometimes referred to as climate control. ... A common modern fume hood. ... Heat recovery ventilation is a ventilation system that employs a heat exchanger between the inbound and outbound air flow to save on energy required for heating (or cooling) the room. ...

See also

• Sick building syndrome
• Heating, Ventilation and Air-Conditioning
• Stack effect