Recognizing Problems

Investigating an IAQ Problem

An IAQ investigation begins with one or more reasons for concern, such as occupant complaints. Some indoor air quality complaints can be resolved very simply (e.g., by asking a few common sense questions of occupants and facility staff during the walkthrough). At the other extreme, some indoor air quality problems could require detailed testing by an experienced IAQ professional. This page offers guidance on performing the most basic of investigations using in-house staff.

Many indoor air quality complaints can be resolved without using all of the diagnostic tools described on this page. For example, it may be easy to identify the source of cooking odors that are annoying nearby office workers and solve the problem by controlling pressure relationships (e.g., installing exhaust fans) in the food preparation area. Similarly, most mechanical or carpentry problems affecting indoor air quality probably require only a few of the many tools you have available and are easily accomplished with in-house expertise.

The use of in-house personnel builds skills that will be helpful in minimizing and resolving future indoor air quality problems. On the other hand, contractors who have specialized knowledge and experience may best handle some jobs. In the same way, diagnosing some indoor air quality problems may require equipment and skills that are complex and unfamiliar. Your knowledge of your own building operations and staff will help you select the right tools and decide whether in-house personnel or outside professionals should be used in responding to the specific IAQ problem. (Personally, we'd rather see you call on a professional ALL of the time, but we're obviously biased.)

Conducting an IAQ Investigation

An IAQ investigation begins with one or more reasons for concern, such as occupant complaints. Some indoor air quality complaints can be resolved by simply asking a few common sense questions of occupants and staff during a walkthrough of the affected areas. At the other extreme, some problems could require detailed testing by an experienced IAQ professional.

The goal of any IAQ investigation is to understand the indoor air quality problem well enough so that you can solve it. Many IAQ problems have more than one cause and may respond to (or require) several corrective actions.

Initial Walkthrough

An initial walkthrough of the problem area provides information about all four of the basic factors influencing indoor air quality (occupants, HVAC system, pollutant pathways, and contaminant sources). The walkthrough may provide enough information to resolve the problem. At least, it will direct further investigation.

Developing and Testing Hypotheses

As you develop an understanding of how the building functions (not how it's designed to function, but rather, how it is functioning at this time), where pollutant sources are located, and how pollutants move within the building, you may think of many "hypotheses," potential explanations of the IAQ complaint. Building occupants and operating staff are often a good source of ideas about the causes of indoor air quality problems.

Collecting Additional Information

If your hypothesis does not seem to be a good predictor of what is happening in the building, you probably need to collect more information about the occupants, HVAC system, pollutant pathways, or contaminant sources.

NOTE: Outside assistance may be needed if repeated efforts fail to produce a successful hypothesis or if the information required calls for instruments and procedures that are not available in-house.

Results of the Investigation

Analysis of the information collected during your IAQ investigation could produce any of the following results:

Using Outside Assistance

Some indoor air quality problems may be difficult or impossible for in-house investigators to resolve. Special skills or instruments may be needed. Other factors can also be important, such as the benefit of having an impartial outside opinion or the need to reduce potential liability from a serious IAQ problem. You are best able to make the judgment of when to bring in an outside consultant. Click here for further information on hiring professional assistance to solve an IAQ problem.