Building Air Quality
DHHS (NIOSH) Publication Number 98-123
Step 3: Address Existing and Potential IAQ Problems
Reference: Building Air Quality - Action Plan: Section 6, "Diagnosing IAQ Problems," Pages 45–79, Section 7; also, "Mitigating IAQ Problems," Pages 81–104.
Purpose: To fix or mitigate all existing or potential IAQ problems in order to protect the health; comfort; and productivity of a building’s occupants and staff.
Using the information on current building conditions and systems from the IAQ Profile, the IAQ Manager can identify practices or conditions that do or could adversely affect indoor air quality. By correcting these conditions and modifying these practices, you will establish a good IAQ baseline in your building.
General Strategies to Correct IAQ Problems:
- Identify sources then remove or reduce the source, seal or cover the source, or modify the environment.
- Improve ventilation to provide outside air to occupants and to dilute and/or exhaust pollutants.
- Improve air filtration to clean air from outside and inside the building.
- Control occupant exposure through administrative approaches such as scheduling contaminant-producing activities during unoccupied periods.
Some IAQ problems are easy to diagnose, especially using the knowledge gained from the Building Air Quality guide and your building’s IAQ Profile. In other cases, IAQ problems can be very complex, and diagnosing them may require outside assistance by IAQ professionals. Such expert resources should be identified before problems occur so that you are ready to solve a problem quickly if one should occur.
The flow chart on page 45 of the Building Air Quality - Action Plan guide shows the general scheme of conducting an IAQ investigation. It is impossible to prescribe one specific set of steps that will work for every IAQ problem. Instead, you should read the Building Air Quality - Action Plan guide, Section 6, for a general understanding of the many tools available for an IAQ investigation.
Some IAQ problems are related to uncontrolled pollutant sources. One pollutant source of concern is biological growth. In order to control or prevent biological contamination, you must address the two elements essential for biological growth: nutrients and moisture. By preventing, or promptly cleaning up, the buildup of dirt or dust and standing water and controlling relative humidity (keep relative humidity (RH) between 30 and 60%, ASHRAE 55-1992 or latest publication; see Appendix 3 for ASHRAE contact information), you can greatly decrease the likelihood of problems associated with biological growth.
Other problems can be linked to deficiencies in the HVAC system, such as uncalibrated controls, inoperable equipment, or inadequate maintenance and operating practices (look for indicators such as torn or overloaded filters, dirty or damaged insulation and inoperable dampers/baffles). These deficiencies can also make it difficult to provide an adequate volume of outside air to flush contaminants from the building.
After diagnosing specific IAQ problems, seek solutions that will correct or mitigate the problems and prevent them from recurring. General strategies to correct IAQ problems include:
- Identifying sources, then removing or reducing the source, sealing or covering the source, or modifying the environment
- Improving ventilation to provide outside air to occupants and to dilute and/or exhaust pollutants
- Improving air filtration to clean air from outside and inside the building; or
- Controlling occupant exposure through administrative approaches such as scheduling contaminant-producing activities during unoccupied periods.
Refer to the Building Air Quality - Action Plan guide, Section 6 and 7, pages 45-104, for a more complete discussion of strategies to correct IAQ problems. In some cases, full mitigation of a problem may require working with others outside of the building. For example, if the source of a problem is idling trucks in an adjacent alley, you may need to educate the drivers about the hazards of unnecessary idling. As you take action to address the issues identified in Step 2 of this action plan, keep records of your progress so you can refer to them later if further questions or related issues arise.
Building Air Quality - Action Plan [PDF - 905 KB]
Building Air Quality [PDF - 2,851 KB]
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