Page 24 - OHS, October 2020

IH: INDOOR AIR QUALITY
New Approaches to Indoor Air Quality
Good indoor air quality (IAQ) can mean a number of things. Here are some factors to consider when evaluating the safety of your air environment.
BY ANDY OLSON
Like the terms beauty, vacation or humor, “indoor air quality” can have a distinctive meaning for different people. In almost all cases, the first aspect of IAQ to consider is
temperature. Buildings that are uncomfortably hot or cold can drive customers away and create ill-will among employees. In fact, studies have repeatedly shown a connection between worker comfort and productivity, with excess heat having a particularly negative effect. Extreme heat can do more than just slow down work, however; it can be outright dangerous, causing a range of ailments from heat stress to heat stroke.
Airborne particulates like smoke or dust are another safety and quality control concern—and not just for laboratory and industrial facility managers. Schools, public buildings and commercial facilities across the country are evaluating their air filtration, ventilation and exhaust systems right now in response to the ongoing COVID-19 pandemic.
Stagnant air can also cause mold- and condensation- related problems, impacting both products and people (as it can cause sick building syndrome and sweating slab syndrome). This is of particular concern for food processing plants and grow facilities. On the opposite side of the spectrum, turbulent air is another
concern for these types of facilities, especially meat processing facilities. According to a University of Nebraska study,1 turbulent air can lead to the spread of airborne disease.
Clearly, IAQ is a multi-faceted problem. While HVAC (heating, ventilation and air conditioning) systems with metal ductwork have traditionally been the primary solution for IAQ control, a number of newer and alternative technologies are now emerging that can supplement or even replace that. We will examine several of them here, including fabric ductwork/air diffusers, HVLS fans and how industrial curtain walls can improve the effectiveness of both.
HVAC and Ductwork
Most buildings with traditional heating and cooling systems have some type of duct system to distribute airflow throughout a building. Ductwork systems en- compass airflow that is mixed with fresh, filtered and conditioned air (heated, cooled, humidified, dehu- midified) and introduced back into the space. Fresh air requirements are more critical, as ASHRAE 62.1 identified the amount of fresh air required based on the type of environment. Similar to urgency for tem- perature, mixing this “fresh air” into the space is im- portant to ensure healthier environments.
20 Occupational Health & Safety | OCTOBER 2020
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