Old HVAC audit
Introduction
Indoor air quality (CAI), in English "indoor air quality" or IAQ is a term that refers to the quality of the air in and around buildings and structures, especially as it relates to the health and comfort of building occupants.
Indoor air quality can be affected by gases (including carbon monoxide, radon, volatile organic compounds), particulate matter, microbial contaminants (mold, bacteria), or any material or energy stressor that can induce adverse health conditions. The main quality control strategies are filtration and the use of ventilation "Ventilation (architecture)") to dilute contaminants.[1] These are the main methods to improve indoor air quality in most buildings.
To understand indoor air quality, air samples must be collected, human exposure to pollutants monitored, samples collected on building surfaces, and computer models of air flow within buildings.
Common contaminants
secondhand smoke
Tobacco smoke is smoke that affects people other than the "active" smoker and is called passive smoking. Tobacco smoke includes a gas phase and a particulate phase, with risks arising from the levels of carbon monoxide and very small particles (PM2.5 in size) that obtain the natural defenses of the lung. The only safe method to improve indoor air quality in terms of secondhand smoke is the implementation of intensive programs of anti-smoking laws.
radon
Radon is an invisible, radioactive gas that results from the decay of radium (Radium (element)), which can be found in rock formations beneath buildings or in certain building materials themselves. Radon is probably the most serious threat to indoor air quality deterioration in the United States and Europe, probably responsible for tens of thousands of lung cancer deaths each year.[2].
There are relatively simple tests to detect radon gas, but these tests are not commonly done, even in areas where systematic risks are known. Radon is a heavy gas and therefore tends to accumulate in basements. Building materials can be a significant source of radon, but there is insufficient evidence: stone, stone or tiles brought to construction sites. Paradoxically, the more thermally insulated a building is, the greater the probability of radon accumulation.[3].