August 13, 2020
Dear students, faculty, and staff,
I want to update you on work that has been done to the ventilation systems around campus. In addition to our normal summer maintenance and preparation, facilities staff have been adjusting Reed’s HVAC systems to meet Center for Disease Control (CDC) and American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) recommendations for mitigating the spread of the virus that causes COVID-19.
These recommendations include the following:
- Maximizing the introduction of outside air during occupied hours.
- Completely flushing air from buildings each day after hours.
- Improving ventilation in bathrooms.
- Confirming the accuracy of digital control systems.
- Using highest-grade filters to catch smaller particles.
We are prioritizing the management of our systems to achieve maximum community welfare. The measures we have taken will increase air exchange and introduce fresh outdoor air at a higher rate. This will have the side effect of making the interior temperatures of buildings more difficult to regulate. In other words, buildings will be chilly during cold weather.
We have made significant improvements to the air flow systems in all buildings where it was feasible. There are some buildings on campus, however, that present structural and mechanical limitations that prevented us from achieving the optimal CDC and ASHRAE recommendations. Where these equipment limitations exist, we are optimizing building flush capability before and after occupied times by other means.
Building-specific details can be found in the facilities HVAC working document. This document will be updated as we monitor the systems.
Additional information about types of circulation
Free-standing HEPA fans and filters
Free-standing HEPA units equipped with filters with a weave of .06 microns or smaller are able to capture viral particles that cause COVID-19. The limitation with this type of unit is a lack of control over the delivery and distribution of the air within the room. In other words, free-standing room units only filter the air that comes into contact with the unit.
The facilities staff does not recommend the use of desk or window fans. Use of fans should be strictly limited to rooms with single occupancy, such as offices with doors. Fans only move air around the room and do not exchange it with fresh air like HVAC systems. Where interior spaces are occupied by more than one person, such as classrooms or office spaces with cubicles, fans will not dilute or remove any virus present and in fact could increase the spread of respiratory droplets. Using a fan to exhaust air out of a window could also be problematic, as that still mixes the air within a room.
The best course of action, in most situations, is to allow passive ventilation in rooms and buildings, even those with no mechanical ventilation systems. Letting the air flow naturally is going to allow it to find its way out of the building with the least amount of mixing.
Information on UV light, room fans, and HEPA filtration
It has been shown that ultraviolet light has some effectiveness in disinfecting surfaces. For this reason, some hospitals and other institutions are using high-intensity UV light to help disinfect areas when they are unoccupied. There are many UV devices that market their ability to kill viral particles in the airstream, but guidance from ASHRAE is that these products should be used with caution, as UV exposure also has its dangers.
In closing, we’ll continue to monitor guidance from the CDC and ASHARE and respond appropriately. Specific data for building air-handling status can be found in the facilities HVAC working document, which we will keep updated.
Director of Facilities Operations