HVAC and Ventilation
What is DU doing to evaluate HVAC systems during COVID?
DU Facilities Management and Planning (FMP) is reviewing the requirements and guidelines from the CDC and CDPHE regarding higher education to determine what changes are needed to HVAC systems. The DU campus has over 90 buildings totaling 4+ million square feet aging from 1892 to today with many different systems. Each building is being evaluated on a case by case basis in coordination with other preventative measures.
What expertise does DU have to evaluate HVAC systems?
DU is fortunate to have several experts in Heating, Ventilation, and Air Conditioning (HVAC) systems. FMP itself has three licensed mechanical professional engineers (PE) on staff who specialize in HVAC. Our HVAC Foreman is an expert in this field whose 25+ years of experience includes working on campuses and in the industry. Additionally, DU has an expert in the Chemistry department who is a bio-aerosol scientist and a DU faculty member assisting our FMP team in our COVID planning efforts. Rest assured, DU has the skills, expertise, and ability to properly evaluate technical solutions and implement appropriate measures to keep our community safe.
Are changes to HVAC systems necessary during COVID?
Changes to HVAC systems are a part of the FMP plan, but not the only piece. Symptom monitoring, face coverings, proper hand hygiene, and maintaining distance are critical individual responsibilities for each person on campus to follow. Additionally, FMP is diligently cleaning and disinfecting spaces daily to reduce the spread. All of these activities are a priority first before major system modifications are made. Finally, HVAC system changes are some of the most expensive measures to implement with long lead times for equipment manufacture and supply.
Has ventilation been adjusted in HVAC Systems in buildings?
Yes, FMP has increased the ventilation rates and use of outdoor air as systems will allow for proper operations. Many buildings on campus have operable windows for additional ventilation.
Are the correct filters being used in HVAC systems to prevent the spread of COVID?
Yes, MERV 13 filters are currently being used in several buildings on campus that have been designed to use them. FMP is investigating installing these filters in buildings that can support them and that the filters can be effective. Many older HVAC systems may not be effective if MERV 13 filters are used as the air may bypass the filter due to pressure in the system.
Will Ultraviolet systems be installed in our HVAC systems?
There is little, if any, supportive evidence in the peer-reviewed scientific literature of UVGI effectiveness in Air Handler Units. Additionally, UV irradiation by itself does not clean air and is not to be used as a stand-alone strategy. It is not to be used as a primary measure to substitute filtration or to reduce ventilation, but as the CDC identifies that the optimal relationship between UVGI and ventilation is not known. UV equipment has been used on campus for disinfecting surfaces, but not in the HVAC systems.
What resources are available that FMP is using to guide decisions?
FMP is following the guidance being promulgated by the EPA, CDPHE, and ASHRAE with the links below to help with decision making: