COVID-19
COVID-19 ASHRAE Guidlines
ASHRAE- The American Society of Heating, Refrigerating and Air-Conditioning Engineers
Dilution
ASHRAE Guidance:
Increase outdoor air ventilation (disable demand-controlled ventilation and open outdoor air dampers to 100% as indoor and outdoor conditions permit.
Specific Measures:
1. Enable Outside Air Economizer mode
2. Encrease Minimum Outside Air
3. Disable DCV (demand control ventilation) used in hot climates.
4. Check airflow to large office areas and conference rooms.
5. Maintain proper pressurization
-Building Pressure, maintain slightly positive
-Toilet Exhaust, maintain slightly negative
6. Consider early startup and delayed shutdown (2 hours)
Filtration
ASHRAE Guidance:
Improve central air and other HVAC filtration to MERV-13 or the highest level achievable.
Specific Measures:
1. Upgrade to MERV-13 filters in AHU’s where possible
-MERV-8 is current commercial minimum standard
2. Seal filters to minimizer bypass air. (duct tape filters together, check for air bypass)
Additional Measures for Higher-Risk Situations
ASHRAE Emergency Response Guidelines:
1. To enhance dilution and filtration, keep systems running longer hours, 24/7 if possible
2. Add portable room air cleaners with HEPA or high-MERV filters.
3. Add upper room and/or portable UVGI devices in high-density spaces (waiting rooms, prisons, shelters).
4. Bypass energy recovery ventilation systems that may leak contaminated exhaust back into the supply air.