At EDS, we think figuring out how to bring staff back to work safely is going to become more and more important as re-opening of the economy progresses. As Mechanical engineers, we rely heavily on guidance from ASHRAE (American Society of Heating Refrigeration and Air Conditioning Engineers), and we use the guidance provided by ASHRAE as well as our years of engineering experience to help our clients in this unique and uncharted situation. We have been following ASHRAEs recommendations carefully and studying the options and ramifications so that we are prepared to present recommendations and design solutions for implementation.
Below you can find links to a brief and a position document that have been issued by ASHRAE about how HVAC can be used to help reduce possible exposure. What they say, in short, is that the filtration and fresh air ventilation provided by HVAC represent a way to reduce possible exposure. The addition of fresh air, filtration (both UV and particulate) are ways to increase the effectiveness of the HVAC system in removing infectious aerosals.
ASHRAEs guidance on measures to be implemented in existing non health care commercial business settings is:
Non-healthcare buildings should have a plan for an emergency response. The following modifications to building HVAC system operation should be considered:
- Increase outdoor air ventilation (disable demand-controlled ventilation and open outdoor air dampers to 100% as indoor and outdoor conditions permit).
- Improve central air and other HVAC filtration to MERV-13 (ASHRAE 2017b) or the highest level achievable.
- Keep systems running longer hours (24/7 if possible).
- Add portable room air cleaners with HEPA or high-MERV filters with due consideration to the clean air delivery rate (AHAM 2015).
- Add duct- or air-handling-unit-mounted, upper room, and/or portable UVGI devices inconnection to in-room fans in high-density spaces such as waiting rooms, prisons, and shelters.
- Maintain temperature and humidity as applicable to the infectious aerosol of concern.
- Bypass energy recovery ventilation systems that leak potentially contaminated exhaust air back into the outdoor air supply.
We are here for our clients to review existing HVAC systems and make recommendations for modifications/upgrades to the existing infrastructure aimed at mitigating the risk involved with infectious aerosols and reopening businesses. Please reach out to us if we can be of assistance.