GOOD INDOOR AIR QUALITY( IAQ)
GOOD INDOOR AIR QUALITY( IAQ)
by Michael Gilmore, LEED AP, and Paul Luster, PE
Good indoor air quality( IAQ) management has become essential in the construction industry with the realization that employee productivity and health are directly related to the quality of air being delivered inside the workplace environment. The IAQ industry is growing as buildings become smarter due to advancements in technology and new building codes require minimum air change rates within occupied buildings. Strategies such as CO2 monitoring, demand-controlled ventilation, ventilation energy recovery, dedicated outdoor air systems, ultraviolet germicidal irradiation, displacement ventilation and underfloor air distribution are becoming more commonplace due to the positive effect on building operations, lower energy costs and improved IAQ.
Commissioning plays an important role in ensuring IAQ requirements meet the intent of the design engineer. The commissioning agent is brought on board early in the design phases and provides review of the construction documents at certain milestones of the HVAC design development. Once the project is awarded to the contractor they are tasked with creating an IAQ plan for the commissioning agent to review and approve. This IAQ plan may require a preoccupancy“ flush out” of the HVAC system to ensure that the air being delivered to the building is free of any dust, chemicals and volatile organic compounds( VOC) that may be residing in the equipment or ductwork that originate from building materials commonly used in construction. Other areas that the commissioning agent considers are temperature, humidity and outside airflow levels.
Several points need to be considered in creating good IAQ for any project or building. Identification of contaminates during the design phase, whether they are inside or outside the building, is very important. For outdoor contaminants, placement of the intakes and discharges of the building is important relative to other emitters that may be present at the building location. Indoor contaminants need to be isolated and captured at the source with either manufactured or properly designed hoods or capture devices. Architectural features must be implemented as the leakage and configuration of dirty spaces are key to the HVAC system’ s success in supporting good IAQ. For ongoing performance, initial commissioning of the building systems and ongoing monitoring of IAQ parameters are very important. Monitoring CO₂ and VOC levels and the simplification of control strategies and equipment components will ensure a building that can maintain the commissioned level of IAQ through the building ' s life.
You can read the in-depth IAQ article here.
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