What are some factors within a building that can affect indoor air quality?
Heating, ventilating and air-conditioning (HVAC) systems can be a source of indoor air quality problems if HVAC filters are not properly fitted, air-conditioning equipment cannot effectively remove moisture from humid air, or air contaminants are drawn into the building through HVAC intakes. Other factors within the building that can also affect indoor air quality can include: indoor activities, laboratories, or new building materials. Water incursion from leaky pipes, sewage, exterior building walls, roofing, or HVAC pipes can permit mold or bacterial growth. High humidity can cause condensation or support mold growth.