Indoor Environmental Issues: Assessing and Managing Your Indoor Environment Quality

Indoor environmental quality focuses on providing an indoor environment that keeps occupants comfortable, productive, and healthy.  The perception of poor indoor air quality manifested by excessive dust build-up, wide temperature variations or uncomfortable temperature can lead to complaints that are sometimes difficult to quantify.  The most common indoor complaints include improper temperature, the perception that air is “stale”, and odors that are “chemical like”, from rodent infestations, and moisture driven moldy odors. 

Balancing energy management with indoor environmental issues can often seem like opposing operational challenges for business owners.  Energy management is about getting the most for the dollars spent on keeping the building at proper temperature.  Keeping all occupants satisfied is a difficult task for a building operator and convincing occupants that the indoor environment is acceptable may require indoor air testing and assessment.

Steps that should be taken before retaining a professional qualified industrial hygiene company to assess the indoor environment should include:

• Maintaining all mechanical systems including filter change-out and cleaning of heating/cooling coils.  Efficiency of heating/cooling coils is drastically reduced when they are dirty. Check fresh air and return air systems for proper operation. 
• Rechecking the balance of the system.  Telltale signs are when diffusers are blocked or redirected, wide temperature swings in the building or inconsistent airflow between diffusers.
• Survey the occupants and determine if more than 10% of the occupants surveyed are complaining of poor indoor air quality.
• Observe the dust burden on surfaces and check custodial procedures.  The recommended minimal filtration is MERV 13 (Minimum Efficiency Reporting Value) but before upgrading filters, determine if the systems can handle these filters without damage.  The higher the efficiency of the filters the more stress it can put on mechanical systems.
• Ensure that building water or moisture incursion is cleaned up and incursion issue fixed as soon as possible (within 24 hours preferred), to reduce the potential of mold growth.

If problems persist it may be appropriate to retain a qualified industrial hygienist to assess the indoor environment.  It is always best to begin with a baseline assessment that would likely include measuring parameters such as temperature, relative humidity, carbon dioxide, carbon monoxide and dust levels.  More sophisticated sampling or investigation may also be needed depending on the issues identified.  Fresh air percentages can be determined using temperature or carbon dioxide differential models.  Air flow can be measured at each diffuser and sources of indoor pollutants evaluated (such as printers, loading docks, outside sources).  Sampling should be performed to WELL or ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) standards. The WELL standard is an evidence-based system for measuring, certifying, and monitoring the building features that impact occupant health.  Typically, the recommended fresh air supply should be 20 cfm/person in occupied spaces so the relative occupancy should be known.  Buildings with persistent water issues may need to be evaluated for mold and there may be other impacts to the indoor environment that would be assessed.  A thorough IEQ assessment will inspect these systems, test for air contaminants (as needed), document conditions and offer a report of findings with conclusions and recommendations.

Prepared by Gary Ritter, CIH, CSP, LEED AP and Milton Jacobs, CSP, MPH.