A ventilation system is a mechanical structure of connected devices that controls airflow within confined spaces, commonly homes and offices. Its main function is to introduce a constant supply of fresh air, usually from the outside, while channeling stale air back out. Fans and pumps are common parts of these systems, as are vent grates and air flow tunnels; in most cases, though, the major working parts are all built within the walls and ducts of structures. People using the space don’t usually see any of the working pieces.
Some of the simplest systems are what’s known as “natural ventilation,” which usually means that they get their airflow through vents opening to the outdoors or windows open to the outside environment. Mechanical systems tend to be more popular, at least in industry; these depend less on atmospheric conditions and can be more tightly regulated. While controlled airflow is usually the primary goal, mechanical systems often also have the capacity to regulate other things, including temperature, relative humidity, and oxygen levels. A lot depends on the setting and the owner’s specific needs.
The main idea behind ventilation is to enable a constant supply of air into some sort of enclosed space. Fresh air is important to health and can prevent things like mold and bacterial growth, and can also prevent the spread of disease. It can help combat things like dust, too, which can lead to cleaner living and working environments. Single rooms can sometimes be ventilated by opening a window or door, but this approach isn’t usually as successful for larger structures, especially ones like office buildings that don’t always have a lot of accessible windows but have many internal corridors.
Ventilation often works in conjunction with heating and cooling systems, but not always. They aren’t limited to buildings, either. Cars, airplanes, and ships also frequently have ventilation passageways and systems that help control air quality and circulation.
In most cases ventilation systems are classified in two broad ways: they are either natural or mechanical. Natural ventilation relies on atmospheric conditions, while a mechanical system is a man-made device that assists in the filtration and circulation of the air. The most common form of a natural system consists of an outlet on the roof and openings throughout the lower part of a building. This allows air to rise and exit through the roof and new air to enter from below, providing constant circulation. It depends somewhat on wind and outside humidity to work properly, though, and isn’t suitable for all climates.
Mechanical systems actively pull fresh air in and push old air out. They may have other capabilities, including heating and cooling, and typically require some form of energy to operate. One common form of mechanical ventilation is the heating, ventilating, and air conditioning (HVAC) units that are used in homes and other buildings.
Some of the most complex mechanical systems are known in industry as “advanced,” and they typically earn this terminology because how much they’re able to do. These are carefully calibrated to control air quality and regulate particulate counts, usually as a safety measure. Sensors positioned at various points in the ducts and vents measure the quality of the air flowing through, then send signals to computers or other communications devices to let owners know the exact readings. They are sometimes designed to set off alarms or shut systems off in the presence of certain readings, too. These sorts of systems are sometimes required by law, particularly in mining operations, in underwater settings like submarines, and in many manufacturing plants and laboratories.
Industry operators in these and other fields may have to comply with local or national air quality guidelines, and these will usually influence their ventilation choices. Some of the choice may also be dependent upon the geographical location of the particular facility. The main purpose of ventilation systems in such settings is to filter harmful substances from the air, provide a constant supply of oxygen, and maintain a healthy atmosphere for breathing.
A ventilation system can be used in conjunction with other equipment to establish desirable temperatures and to maximize the air circulation. It is not uncommon for large buildings and warehouses to be equipped with exhaust fans that assist in bringing in fresh air in while pushing the old out. These fans may be placed at various ventilation openings throughout the building or on the roof. A system with exhaust fans is often used in buildings that generate substantial amounts of heat or discharge air that contains fumes.