The thermal environment (temperature, relative humidity and airflow) are important dimensions of indoor air quality for several reasons. First, many complaints of poor indoor air may be resolved by simply changing the temperature or relative humidity. Second, people that are thermally uncomfortable will have a lower tolerance to other building discomforts. Third, the rate at which chemicals are released from building materials is usually higher at higher building temperatures. Thus, if occupants are too warm, it is also likely that they are being exposed to higher pollutant levels.
Indoor thermal conditions are controlled by the heating, ventilating, and air conditioning (HVAC) system. How well the thermal environment is controlled depends on the design and operating parameters of the system, and on the heat gains and losses in the space being controlled. These gains and losses are principally determined by indoor sources of heat, the heat gains from sunlight, the heat exchange through the thermal envelope, and the outdoor conditions and outdoor air ventilation rate.
According to the Environmental Protection Agency, problems with the Heating, Ventilation, and Air Conditioning Systems that can affect IAQ and how they might be addressed:
|Contaminated Filters||Perform HVAC preventive maintenance|
|Contaminated duct lining||Use filter change protocol|
|Dirty drain pans||Clean drain pans; proper slope and drainage|
|Humidifiers||Use potable water for steam humidification|
|Lubricants||Keep duct lining dry; move lining outside of duct if possible|
|Refrigerants||Fix leaks/clean spills|
|Mechanical room||Maintain spotless mechanical room (not a storage area)|
|Maintenance activities||Avoid back drafting
|Combustion appliances||Keep combustion appliances properly tuned. Disallow unvented combustion appliances|
|Boilers/furnaces||Check/maintain flues from boiler to outside|