Commercial environments are characterized by hundreds of sources producing multiple contaminants at much lower than industrial levels. Indeed, exceeding occupational standards in a non-industrial environment would indicate very serious indoor air quality concerns. In commercial environments, indoor air quality depends on how these sources and contaminants interact with air flow patterns, heat and humidity factors, and occupant patterns in time and space within the building. Looking for patterns and relationships in source emissions, occupancy, activities, ventilation and direction of airflow is most productive in these cases.
Measurements are designed to characterize the amount of outdoor air that is delivered to occupants, comfort indicators, the performance of the HVAC system, pressure relationships, and air flow patterns that could transport contaminants from potential sources to the occupied areas of the building. Measurements of specific contaminants are very seldom warranted.
General Diagnostic Process for Commercial Facilities
Generally, there are three steps in a diagnostic process.
- Determine if this is an emergency. If it is, take actions immediately to protect occupants and property. Determine if the problem is building related and, if it is, continue with steps 2 and 3.
- Proceed through a deliberate process of characterizing problem finding clues as to causes, and communicating with occupants and operators.
- Check specific causes until the problem is solved.
Identifying an Emergency
Emergencies are situations in which a limited time is available to avert or deal with serious health problems or property damage. Examples include:
- Hazardous material spills
- Flooding on porous materials
- Gray water (e.g., sewer) spills
- Gas leak
- Sudden onset of headaches, dizziness, drowsiness, nausea, and/or combustion odors (could be carbon monoxide poisoning)
- Widespread breathing difficulties, chest tightness, or respiratory irritation (potential serious infectious or allergenic agent)
- Diagnosed Legionnaires disease or tuberculosis
Taking Action in an Emergency
The object of initial action in emergency situations is to deal with the situation creating the hazardous conditions first, including getting people out of harm’s way.
- Immediately notify and seek assistance from an appropriate authority (e.g. health department, hazardous waste office, fire department, gas utility etc.)
- Evacuate the area if needed
- Obtain medical assistance
- Ventilate affected areas with large quantities of outdoor air using temporary fans if necessary
- Inform building occupants of problem, what is being done, and maintain clear communications
- Begin remediation procedures
Characterizing Problems
Purpose
The processes in this phase are designed to diagnose and solve typical indoor air quality problems that are not emergencies. The information provided is designed to help the user develop a diagnostic way of thinking about indoor air quality problems. I-BEAM also provides a set of forms to aid in diagnosing and solving problems.
Iterative Diagnostic Process
An IAQ investigation is like detective work - defining the problem, looking for clues, and finding a solution through an iterative process of narrowing the possible causes, and developing and testing hypotheses. (see Flow Chart for example).
Clues may be found in basic information about the problem. Seeking the right information from occupants, examining building components with an educated eye, and making some simple diagnostic measurements can probably solve most problems. Determine:
- What are the symptoms? What are the symptoms or substance of the complaint? Answers can give clues as to potential type of cause(s) (e.g. type of contamination, inadequate outdoor air, temperature/humidity issue, etc.).
- Where is the problem? Local or widespread, in one HVAC zone or more, on one side of the building or all sides, one floor/room or throughout the building? Answers can give clues as to the nature of the cause(s) such as a local source or local HVAC component problem, or a source that is widespread throughout the building, a central HVAC problem, a problem common to all air handlers or just one.
- When does it occur? Times, time pattern, time in relation to individual activities, time in relationship to other activities in the building, time in relation to occupancy in building? Answers can give clues as to whether it is related to the building or elsewhere, and what activities may be associated with the cause(s), whether the cause(s) are occupant related or building related.
- Who is the problem experienced by? An individual or several, just in person(s) with preexisting sensitivities or across the board? Answers provide clues as to whether or not the individual(s) may have special needs that, if accommodated, could solve the problem.
Use I-Beam's Occupant Complaint Record forms to help collect this information.
