Air Quality Solutions

By: Christopher Collett & Associates  09-12-2011
Keywords: air quality, indoor air quality

The cost of investigating, identifying, and resolving indoor air quality (sick building) problems is probably less than you think.  In fact, many problems are addressed with simple adjustments to the heating & ventilation system, and appropriate regular maintenance.

Some common problems include:

  • insufficient outside air supply

  • poor indoor air distribution

  • inappropriate thermostat settings / configuration

  • poor filtration

  • lack of regular & preventative maintenance

Issues that are more difficult to identify and solve include:

  • presence of contaminants from interior furnishings and finishes (paint, carpet, adhesives, etc.)

  • Contaminants from occupant activities and equipment (solvents, cleaning products, copiers, etc.)

  • Microbial contamination (mold, mildew, etc.) from water leakage into the building envelope.

Here are some examples of client experiences in the past:

Example 1

Building:  Bank
Problem:  Staff reporting excessive dust and vehicle odours in part of branch.
IAQ Measurement:  Dust and CO levels were 5 times higher in the area compared to elsewhere.
Identified Cause:  Negative pressure due to inadequate outside air supply from HVAC system, and continuous operation of washroom fans caused infiltration of unfiltered air from street level, and flowed right through area of concern.
Solution:   Increased minimum outside air damper position (increased outdoor air flow).
Outcome: Slight positive pressurization of indoor space, eliminating infiltration of street air. Airborne dust and CO levels were reduced.
Mitigation Costs:  Low cost adjustment of HVAC system, and slight increase in energy consumption with increased air flow.

Example 2

Building:  Suburban Office
Problem:  Occupants reported inconsistent temperatures (primarily cold) and occasional stuffiness in one area.
IAQ Measurement:  Wide variations in space temperatures on a daily basis, and periodically elevated CO2 levels.
Identified Cause:  Inappropriate location and configuration of thermostat. The thermostat was located right above a large copier. Consequently, the thermostat was sensing much warmer conditions than elsewhere in the area. The thermostat was also configured for intermittent operation of the fans, resulting in the periodically elevated CO2 readings.
Solution:   Relocated the copier away from the thermostat, and configured the thermostat for continuous fan operation.
Outcome: Reduced temperature variations and CO2 levels, which eliminated occupant complaints.
Mitigation Costs:  Minimal.

Example 3

Building:  School
Problem:  Musty odours in a classroom
IAQ Measurement:  Elevated airborne fungal concentrations in the room.
Identified Cause:  Swab samples showed elevated surface fungal levels on the carpets. Review of cleaning practices showed that moisture was probably left in carpets post cleaning during summer recess.
Solution:   Remedial cleaning using a dry vacuum (HEPA) did not remove the contamination, so they replaced the carpet with a linoleum surface.
Outcome: Elimination of the odour problem (although the teacher reported increased noise with the hard floor surface!)
Mitigation Costs: 

Costs associated with the carpet replacement. The district revised its carpet cleaning program to stress the importance of moisture removal to minimize the potential for microbial growth.

Contact  Christopher Collett & Associates Ltd. for more information about identifying and resolving air quality problems in your workplace.  It costs less than you think, and results in increased productivity and more satisfied employees.

Keywords: air quality, indoor air quality

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