Battling COVID-19

How can your building help fight the battle against COVID-19?

Our world has reacted to our recent health crisis by implementing societal changes and our buildings need to react too. One of the many variables impacting the spread of infectious diseases that shouldn’t be overlooked are HVAC systems within buildings. The American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) has released a position document on infectious aerosols based on decades of research to help individuals understand how HVAC systems and indoor air management can aide in addressing infection control, and as our businesses begin to open back up, there are a number of things building maintenance personnel should address. The engineering team at Green Acorn has referenced ASHRAE’s position paper and provided additional recommendations to implement in reopening and maintaining your building’s systems.


Measures that a building owner may consider to mitigate the risk of infection spreading after a facility has opened:

  • Modify building controls to introduce more outside air into the building

  • Ensure HVAC systems are setup to have economizer controls integrated with the cooling system

    • Ensure adequate air pressure relief devices are installed and operating correctly

  • Add air purification modules to existing air handling equipment

    • UV lights will eliminate airborne pathogens*

    • Needlepoint bipolar ionization can also eliminate airborne particulates, odors and pathogens

  • Add upper room UVGI lights to densely occupied spaces*

  • Install MERV 13 air filters or higher efficiency air filters where able

  • Run the ventilation system 24/7*

  • Perform retro-commissioning of HVAC systems to ensure proper functionality


Measures to take before reopening your building:

  • Purge your building with outside air to replace all the stale indoor air with fresh, contaminant free air.

    • When the weather is cool and the humidity is low, initiate the economizer cycle on all air handlers to introduce 100% outside air. Ensure pressure relief equipment (power exhaust or barometric relief dampers) are operating correctly. Open doors and windows if pressure relief equipment does not exist or is not operational.

  • Replace air filters

  • Blow out condenser coils

  • Clean exhaust and return grilles

  • Test smoke detectors and CO detectors

  • Ensure all plumbing traps are sealed so sewer gas does not leak into the space.

    • To seal a plumbing trap, pour two liters of water into every plumbing fixture with a drain

  • Exercise your plumbing fixtures to ensure pipes are flushed of stale water and are operating properly

    • Flush Toilets

    • Turn on hot and cold water to sinks

  • Ensure proper water heater operation and set water temperature to 140°F or greater to reduce the risk of legionella, and test water heater pressure relief valves

  • Check local hot water temperatures at fixtures and adjust thermostatic mixing valves to achieve 105°F hot water at lavatories and 110°F hot water at showers

  • Turn on your hot water recirculation pump

  • Clean out grease traps and oil separators

  • Clean roof drains and emergency roof drains

  • Clean storm sewer grates

  • Check sump pump operation. If you have a duplex pump, make sure both pumps work and stage properly

  • Clean grease hoods and grease duct Inspect fire extinguishers

  • Clean strainers, heat exchangers, and cooling tower basins

 *ASHRAE recommendations. Reference the full ASHRAE Position Document on Infectious Aerosols here.

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