As we navigate new information daily about Covid-19, building managers are tasked with finding safe ways to reopen facilities. And the clock is ticking with buildings that are scheduled to reopen in early fall, adding pressure to use current CDC guidelines to assuage the threat of a disease that is not fully understood.
Indoor air quality is in the spotlight in terms of mitigation strategies. Indoor air quality has become a top priority for building managers as businesses navigate how to operate and reopen their doors to occupants safely. With an illness such as Covid-19, which can transmit through vapor droplets in the air, it is reasonable to assume that it can travel through some saturation level. If occupants are spending substantial amounts of time inside a building, the virus could spread person-to-person through the air. So, in addition to surface cleaning processes, additional attention to air conditioning must also be considered.
Increased Ventilation and Outdoor Air
One methodology that facility managers are already implementing is increasing building ventilation to provide more outside air to occupants. While there are passive ways, such as opening windows and doors, this is not a maintainable solution for most buildings that require temperature and humidity controls. Alternatively, ASHRAE guidelines indicate that building operators can increase ventilation rates of spaces while also maintaining comfort levels of occupants.
Most central air handling units for commercial buildings and institutions have outdoor air intakes that allow the units to mix fresh air with return air from the indoor spaces. The amount of outdoor air can be controlled from the Building Automation System (BAS) that can modulate actuators on dampers to a set percentage open based on the outdoor air requirements. Spaces with CO2 sensors can measure the CO2 levels in an area indicative of occupants in a space for some time long enough to generate a certain ppm level that can be measured by the sensor. Programming the unit to allow more outside air in an area based on this measurement is one way to cycle potentially contaminated air from the space to be replaced with fresh, uncontaminated outside air.
Increased Filtration Media Standards
Filtration media can be used to mitigate the spread of airborne particulates as well as viruses and bacteria. Ducted return air to central air handling systems typically has some level of MERV-rated filtration that can reduce the number of particulates that are recycled in the building's air exchanges. Filter ratings are scaled by their ability to prohibit a specific range of particulate sizes from carpet fibers down to microscopic allergens and virus carriers. Building managers can evaluate their central air systems for potential filter upgrades and balance the possible loss in static pressure by reprogramming fan speeds to maintain building comfort.
Bipolar Ionization in Central Air Conditioning Systems
Aside from increased ventilation and filtration media, more attention is now being paid to the use of bipolar ionization to slow the spread of Covid-19. Ionization is a process that takes charged oxygen atoms, which then cluster around microparticles or droplets on surfaces to deactivate potential pathogens. Although hospital facilities have been using bipolar ionization for years, its use on other types of buildings has yet to be fully explored. Currently, there is no conclusive data for its feasibility. And because devices must be installed at each air conditioning unit serving an area, it can also be a costly method, adding tens of thousands of dollars to a project or building's budget.
Combined with other IAQ strategies, bipolar ionization may be an effective method for safely reopening buildings. But it should be taken under careful consideration by building managers and decision-makers.
While we are still learning about the transmission of the virus and ways to mitigate it, these strategies can be employed to improve the overall indoor air quality of buildings in general, which can help reduce the likelihood of transmission. Strategies will need to be fluid to adapt to the changing guidance, and building managers will need to be vigilant in enforcing new means and methods. But along with the implementation of more stringent and frequent cleaning processes, businesses and institutions alike may be able to reduce the spread of pathogens and even Covid-19 so that they may return to a minimum the semblance of normal operations.
How We Can Help
PhoenixET can help facility managers make bulk changes that may be required at multiple sites as buildings reopen. We can identify issues remotely, see what equipment may not be running (or not running optimally), and can optimize systems to save on energy to bring costs significantly down. We have industry-perfected ECMs (energy conservation measures) that we implement for our customers that do not require new hardware or equipment.
Reach out to us to see how we can help get you ready for when your buildings reopen.
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