Final answer:
Ventilation is the process of air exchange in buildings, using infiltration, natural, and mechanical means to ensure an adequate air exchange rate, which is crucial for maintaining indoor air quality.
Step-by-step explanation:
Ventilation is a combination of processes that results in the supply and removal of air from inside a building. This includes infiltration, where air seeps into the building through openings, and natural ventilation, which involves air movement through open windows and doors. Additionally, there are mechanical ventilation systems that use fans and duct work to manage the flow of air.
Infiltration happens when outside air enters through joints and cracks in the building's structure or around windows and doors. Natural ventilation's air movement is due to temperature differences between indoors and outdoors, and by wind. Mechanical ventilation systems actively circulate air by removing indoor air and replacing it with filtered and conditioned outdoor air.
Homes and buildings implement measures such as weather stripping, caulking, and improved window seals to manage air exchange rates, which describe how quickly outdoor air replaces indoor air. However, if the air exchange rate is too low, indoor air pollutant levels can increase, highlighting the need for sufficient ventilation to supply oxygen and dilute pollutants.