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Step 3: Address Existing and Potential IAQ Problems
Reference: Building Air Quality: 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 from the IAQ Profile, the IAQ Manager can identify current practices or conditions that could, or already do, 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 in order 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 to pollutants 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 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 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. You can greatly decrease the likelihood of problems associated with biological growth by preventing, or promptly cleaning up, the buildup of dirt or dust and standing water, and by controlling relative humidity (keep relative humidity between 30 and 60%, see American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 55-1992 or latest publication; see Appendix 3 for ASHRAE contact information).

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:

Refer to the Building Air Quality 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.

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