Many of our clients have asked about options to address indoor air quality in response to COVID-19. According to the American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE) position document on Infectious Aerosols, HVAC systems can affect the transmission of infectious diseases transmitted through aerosols. Decreasing exposure is an important step in curtailing the spread of infectious diseases. Although we cannot remove 100% of all airborne contaminants, with modifications to air filtration, air flow and humidity, we can help to limit airborne transmission risk.
Air Filtration is an important element of indoor air quality, If the virus is captured in the filtration system, then the virus will not be spread throughout the inside of the building. In most commercial HVAC systems, filters are used to remove particulate from the air. These filters are measured in MERV (Minimum Efficiency Reporting Values). The MERV measurement ascends in quality from MERV 1 through MERV 20, which is the highest. The most common found in a commercial Air Handling Unit (AHU) are MERV 6 to MERV 8. ASHRAE recommends a higher efficiency rating, ideally MERV 13 or MERV 14. For additional protection, Ultraviolet Germicidal irradiation (UVGI) systems can be added to irradiate the virus particles via ultraviolet light.
Air Flow is another critical element of indoor air quality. HVAC controls should ensure adequate air supply and exhaust vents and, in the case of partitions or curtains, secondary measures to maximize ventilation effectiveness, such as opening windows and doors. This is particularly important in buildings which may not have adequate ventilation. In areas of known air stagnation, other air circulation systems can also be used, but only if they also bring in outdoor air. Smaller rooms may benefit from portable consumer air-cleaning devices, if they have clean air-delivery rates of 15 to 575 ft3/min and their filters are changed as recommended.
Good air flow will also assist with the third critical element of indoor air quality – humidity control. Higher relativity humidity has been proven to be detrimental in containing virus spread. Maintaining a relative humidity of 40% to 60% inside your facility, will decrease the virus’ ability to infect occupants.
Lastly, for modifications to buildings, the 2020 Coronavirus Aid Relief, and Economic Security or “CARES Act” contains several tax savings opportunities for businesses. This includes a change to the tax code to ensure “qualified improvement property” (QIP) investments can benefit from an accelerated tax deduction for the full cost of such property. Under Section 168 of the tax code, the cost of all equipment and components of the “heating, ventilating, and air conditioning system” (among other items which are considered QIP) can be fully deducted for tax purposes in the first year it’s placed in service versus over a 39 year period. For commercial buildings, the cost of HVAC equipment placed into service in 2020 may be fully deducted as a business expense.
Contact Timberhood Consulting for assistance getting your building HVAC ready for occupants to return to your facility. We’d love to help assess your building’s systems and advise you on the best practices to keep your occupants safe as they return to work.