Diagnosing IAQ Problems

Diagnosing IAQ Problems he goal of the diagnostic building T Start (reason for concern) investigation is to identify and solve the indoor air quality complaint in a way that t 6 prevents it from recurring and that does not Initial walkthrough n preparation create other problems. This section n visual inspection describes a method for discovering the n talk with occupants and staff cause of the complaint and presents a t “toolbox” of diagnostic activities to assist Do you have Yes you in collecting information. an explanation Just as a carpenter uses only the tools for the complaint ? that are needed for any given job, an IAQ No investigator should use only the investiga- t Collect additional tive techniques that are needed. Many information about indoor air quality complaints can be n building occupants resolved without using all of the diagnostic n the HVAC system n pollutant pathways tools described in this chapter. For n pollutant sources example, it may be easy to identify the (sample contaminants if needed) source of cooking odors that are annoying t nearby office workers and solve the Develop one or more hypotheses problem by controlling pressure relation- to explain the problem. Test by ships (e.g., installing exhaust fans) in the manipulating building conditions or exposure, or by performing food preparation area. Similarly, most appropriate tests. mechanical or carpentry problems probably require only a few of the many tools t t you have available and are easily accom- Do results Attempt plished with in-house expertise. No Yes Follow-up support your a control validation The use of in-house personnel builds hypothesis ? strategy skills that will be helpful in minimizing and resolving future problems. On the t other hand, some jobs may be best handled Is the by contractors who have specialized No problem Yes knowledge and experience. In the same solved ? way, diagnosing some indoor air quality problems may require equipment and skills t that are complex and unfamiliar. Your FIGURE 6-1: Make necessary Conducting an IAQ Investigation changes so that knowledge of your organization and the problem will building operations will help in selecting Note: Outside assistance may be needed at any not recur. the right tools and deciding whether in- point in the investigation, depending upon the complexity of the problem, the skills available in- t house personnel or outside professionals house, time pressures, or other factors. Finish should be used in responding to the specific IAQ problem. Diagnosing IAQ Problems 45 OVERVIEW: CONDUCTING AN tions of the IAQ complaint. Building IAQ INVESTIGATION occupants and operating staff are often a good source of ideas about the causes of An IAQ investigation begins with one or the problem. For example, they can more reasons for concern, such as occu- describe changes in the building that may pant complaints. Some complaints can be have occurred shortly before the IAQ resolved very simply (e.g., by asking a few problem was noticed (e.g., relocated The IAQ investigation common sense questions of occupants and partitions, new furniture or equipment). facility staff during the walkthrough). At is often a repetitive Hypothesis development is a process the other extreme, some problems could cycle of information- of identifying and narrowing down require detailed testing by an experienced gathering, hypothesis possibilities by comparing them with your IAQ professional. In this section “the observations. Whenever a hypothesis formation, and investigator” refers to in-house staff suggests itself, it is reasonable to pause hypothesis testing. responsible for conducting the IAQ and consider it. Is the hypothesis investigation. consistent with the facts collected so far? The flowchart on page 45 shows that You may be able to test your hypothesis the IAQ investigation is a cycle of infor- by modifying the HVAC system or mation-gathering, hypothesis formation, attempting to control the potential source and hypothesis testing. The goal of the or pollutant pathway to see whether you investigation is to understand the IAQ can relieve the symptoms or other condi- problem well enough so that you can solve tions in the building. If your hypothesis it. Many IAQ problems have more than successfully predicts the results of your one cause and may respond to (or require) manipulations, then you may be ready to several corrective actions. take corrective action. Sometimes it is difficult or impossible to manipulate the Initial Walkthrough factors you think are causing the IAQ An initial walkthrough of the problem area problem; in that case, you may be able to provides information about all four of the test the hypothesis by trying to predict how basic factors influencing indoor air quality building conditions will change over time (occupants, HVAC system, pollutant (e.g., in response to extreme outdoor pathways, and contaminant sources). The temperatures). initial walkthrough may provide enough information to resolve the problem. At the Collecting Additional least, it will direct further investigation. Information For example, if the complaint concerns an If your hypothesis does not seem to be a odor from an easily-identified source (e.g., good predictor of what is happening in the cooking odors from a kitchen), you may building, you probably need to collect want to study pollutant pathways as a next more information about the occupants, step, rather than interviewing occupants HVAC system, pollutant pathways, or about their patterns of discomfort. contaminant sources. Under some circumstances, detailed or sophisticated Developing and Testing measurements of pollutant concentrations Hypotheses or ventilation quantities may be required. As you develop an understanding of how Outside assistance may be needed if the building functions, where pollutant repeated efforts fail to produce a successful sources are located, and how pollutants hypothesis or if the information required move within the building, you may think calls for instruments and procedures that of many “hypotheses,” potential explana- are not available in-house. 46 Section 6 Results of the Investigation serious IAQ problem. You are best able to make the judgment of when to bring in an Analysis of the information collected outside consultant. See Section 8 for a during your IAQ investigation could discussion of hiring professional assistance produce any of the following results: to solve an IAQ problem. The apparent cause(s) of the complaint(s) are identified. INITIAL WALKTHROUGH Remedial action and follow-up evaluation An investigation may require one or many will confirm whether the hypothesis is visits to the complaint area. The amount correct. of preparatory work needed before the Other IAQ problems are identified that initial walkthrough varies with the nature are not related to the original complaints. and scope of the complaint and the These problems (e.g., HVAC malfunc- expertise of the investigator, among other tions, strong pollutant sources) should be factors. For example, an in-house investi- corrected when appropriate. gator who is already familiar with the layout and mechanical system in the A better understanding of potential IAQ building may begin responding to a problems is needed in order to develop a complaint about discomfort by going plan for corrective action. directly to the complaint area to check the It may be necessary to collect more thermostat setting and see whether air is detailed information and/or to expand the flowing from the supply outlets. scope of the investigation to include If the investigator is not familiar with building areas that were previously the building or is responding to complaints overlooked. Outside assistance may be that suggest a serious health problem, more needed. preparation may be needed before the initial walkthrough. The activities listed The cause of the original complaint below can be directed at a localized cannot be identified. “problem area” or extended to include the A thorough investigation has found no entire building: deficiencies in HVAC design or operation or in the control of pollutant sources, and Collect easily-available information about there have been no further complaints. In the history of the building and of the the absence of new complaints, the original complaints. complaint may have been due to a single, Identify known HVAC zones and com- unrepeated event or to causes not directly plaint areas. related to IAQ. Begin to identify potential sources and pollutants (e.g., special use areas near the Using Outside Assistance complaint location). Having a copy of Some indoor air quality problems may be mechanical and floor plans can be helpful difficult or impossible for in-house at this stage, especially if they are investigators to resolve. Special skills or reasonably up-to-date. instruments may be needed. Other factors Notify the building occupants of the can also be important, such as the benefit upcoming investigation. of having an impartial outside opinion or the need to reduce potential liability from a Tell them what it means and what to expect. Diagnosing IAQ Problems 47 Identify key individuals needed for access to describe the operating schedule of and information. equipment. Obvious problems (e.g., A person familiar with the HVAC systems blocked diffusers, malfunctioning air in the building should be available to assist handlers) can be corrected to see if the the investigator at any time during the complaints disappear. The walkthrough onsite phase. Individuals who have can solve many routine IAQ problems and complained or who are in charge of will suggest directions for a more complex potential sources (e.g., housekeeping, non- investigation, should one be necessary. HVAC equipment) should be aware that Some investigators avoid taking any their information is important and should measurements during the initial walk- be contacted for appointments or telephone through so that they are not distracted from interviews if they will not be available “getting the big picture.” Others find that during the onsite visit.

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