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Coronavirus: Engineering and Physical Changes Best Practices for your business

Coronavirus: Engineering and Physical Changes Best Practices for your business

If you are a business owner looking for guidance to project your employees, your customers yourself and your business itself from this of coronavirus (both the health risk and the business liabilities) the resources on this page and those linked to below will be helpful.

Physical and engineering changes to maintain a healthy work environment

Since COVID-19 may be spread by those with no symptoms, businesses and employers should evaluate and institute controls according to the hierarchy of controls to protect their employees and members of the general public.

Consider improving the engineering controls using the building ventilation system. This may include some or all of the following considerations:

• Bring fresh air in: Increase outdoor air ventilation, using caution in highly polluted areas.

• When weather conditions allow, increase fresh outdoor air by opening windows and doors. Do not open windows and doors if doing so poses a safety or health risk (e.g., risk of falling, triggering asthma symptoms) to occupants in the building.
• Use fans to increase the effectiveness of open windows. To safely achieve this, fan placement is important and will vary based on room configuration. Avoid placing fans in a way that could potentially cause contaminated air to flow directly from one person over another. One helpful strategy is to use a window fan, placed safely and securely in a window, to exhaust room air to the outdoors. This will help draw fresh air into room via other open windows and doors without generating strong room air currents.
• Decrease occupancy in areas where outdoor ventilation cannot be increased.
• Ensure ventilation systems operate properly and provide acceptable indoor air quality for the current occupancy level for each space.
• Increase airflow to occupied spaces when possible.
• Turn off any demand-controlled ventilation (DCV) controls that reduce air supply based on occupancy or temperature during occupied hours. In homes and buildings where the HVAC fan operation can be controlled at the thermostat, set the fan to the "on" position instead of "auto," which will operate the fan continuously, even when heating or air-conditioning is not required.
• Open outdoor air dampers beyond minimum settings to reduce or eliminate HVAC air recirculation. In mild weather, this will not affect thermal comfort or humidity. However, this may be difficult to do in cold, hot, or humid weather.
• Improve central air filtration:
  • Increase air filtration to as high as possible without significantly reducing design airflow.
  • Inspect filter housing and racks to ensure appropriate filter fit and check for ways to minimize filter bypass.
  • Check filters to ensure they are within their service life and appropriately installed.
• Ensure restroom exhaust fans are functional and operating at full capacity when the building is occupied.
• Inspect and maintain local exhaust ventilation in areas such as kitchens, cooking areas, etc. Operate these systems any time these spaces are occupied. Consider operating these systems, even when the specific space is not occupied, to increase overall ventilation within the occupied building.
• Consider portable high-efficiency particulate air (HEPA) fan/filtration systems to help enhance air cleaning (especially in higher risk areas such as a nurse's office or areas frequently inhabited by persons with increased risk of getting COVID-19).
• Generate clean-to-less-clean air movement by re-evaluating the positioning of supply and exhaust air diffusers and/or dampers (especially in higher risk areas).
• Consider using ultraviolet germicidal irradiation (UVGI) as a supplement to help inactivate SARS-CoV-2, especially if options for increasing room ventilation are limited. Upper-room UVGI systems can be used to provide air cleaning within occupied spaces, and in-duct UVGI systems can help enhance air cleaning inside central ventilation systems.

Note: The ASHRAE Guidance for Building Operations During the COVID-19 Pandemic provides further information on ventilation and building operations during the COVID-19 pandemic.

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