As scientists learn more about SARS-CoV-2, the virus that causes COVID-19, it is clear aerosolized virus from exhalation plays a primary role in transmission. The operation of heating, ventilation, and air-conditioning (HVAC) systems can help reduce the concentration of virus, thereby reducing the risk of transmission. This is done primarily through increasing the amount of outside air introduced into a building through its HVAC system’s outdoor air intake. However, underconditioned spaces can cause thermal stress to people that may be directly harmful or lower their resistance to infection. Therefore, modifications to the amount of outside air must not exceed the system’s ability to condition the air. The College is following the guidance provided by the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) in implementing operational modifications to help mitigate the risk of exposure.
Increased Percentage of Outdoor Air
All campus buildings with central air handling will be set to increase the percentage of outdoor air intake to the point that the HVAC system can still condition the air. Occupants can expect that this increase in fresh air will have an impact on the ability of the system to control temperature and humidity and should plan for less thermal comfort. The amount of fresh air that can be introduced into the building will vary in accordance with outdoor air conditions. Opening windows in these buildings is discouraged, because this will further impede the ability of the HVAC systems to condition the air.
Central Air Filtration
All buildings are receiving new filters prior to the beginning of the academic year. These are high quality filters that meet the design specifications of the system in which they are used. They are not in all cases HEPA filters, which capture particles down to .3 microns. This is because that level of filtration may impede that system’s ability to draw air through the filter, negatively impacting the system’s ability to circulate air.
Forced Air System UV Treatment
For buildings with residential type forced air systems, UV treatment modules are being installed at the furnace. This will expose the air to UV light as it passes through the furnace, which has been shown to kill the virus.
Local Electrostatic Air Purification
In special situations, where increasing the outdoor air may be difficult, or the virus load is more localized, electrostatic air purification units will be installed. For instance, singing is known to project exhalation further, so spaces used by groups for this purpose will have stand-alone electrostatic air purifiers.
Single Occupancy – Radiant Heat Only
Some buildings on campus, typically residence halls, do not have centralized air handling, only radiant heat. These buildings have exhaust fans that exchange air in bathrooms, but individual bedrooms have only heating radiators. In these cases, each bedroom has only one occupant, and they have control over who enters the space. Occupants are encouraged not to have guests. These rooms also generally have operable windows that allow them to introduce fresh air directly, but they will need to cooperate with other occupants who may be affected through shared thermostat zones.
The following is a list of buildings or building groups that will help occupants know what to expect in their specific circumstances.
Admissions Center, Anderson Athletic Center, Arcus, Dewing Hall*, Fieldhouse, Fitness & Wellness Center, Hicks Center, Light Fine Arts*, Mandelle Hall, Stetson Chapel, and Upjohn Library Commons
This group of buildings all have centralized air handling. Fresh air will be increased to the point where conditioning can still be maintained. Occupants should expect that thermal conditions will be less controlled than normal. Operable windows should NOT be opened.
* Dewing Hall: 3rd Floor Instructional Spaces, and Light Fine Arts: Singing and Wind Instrument Instructional Spaces: These specific spaces within buildings already listed above will have electrostatic air purifiers within the instructional spaces. Thermal conditions will be less controlled than normal, as the main air handler will have increased outside air.
This building normally operates with 100% outside air due to the nature of the laboratory work within. This will be operated as normal.
This building has central air-handling; however, the thermal conditioning is limited and the building houses sensitive scientific equipment. To maintain conditioning, the outdoor air will be increased only moderately when possible, and electrostatic air purifiers will be operated in the instructional spaces. Operable windows should NOT be opened.
This building has a central make-up air unit, but thermal controls are dispersed in zones throughout the building. Operable windows may be opened, occupants will need to cooperate with those in adjacent spaces.
Crissey, DeWaters, Harmon, Hoben, Severn, Trowbridge
This group of buildings does not have centralized air handling. Bathroom air is exchanged with exhaust fans and bedrooms will be single occupancy. Operable windows may be opened, occupants will need to cooperate with those in adjacent spaces. Common spaces will be arranged to allow only socially distant occupancy and gatherings will be discouraged.
Living Learning Houses
Living Learning units in individual houses will have UV light treatment installed on their furnaces, these spaces will operate as normal. Operable windows may be opened, occupants will need to cooperate with those in adjacent spaces.