Ventilation and HVAC Frequently Asked Questions (FAQs)
Q. What has (and is) being done regarding increased and/or better ventilation and air filtration in our classrooms and buildings on both campuses.
A. The district has taken preventative measures and is investigating other options to improve indoor ventilation. To date, all mechanical units with dampers have been opened as wide as possible so that nearly 100% outside air is being used for ventilation, which minimizes the recirculation of indoor air. Most buildings in the district have mechanical units with dampers.
In addition, the following actions are under way:
At both campuses, where applicable the lower grade MERV 8 filters have been replaced with MERV 13 filters, which are the highest grade the HVAC equipment can support. Furthermore, these filters are rated as most effective in trapping airborne particles. At De Anza only the Media and Learning Center (MLC) and portable buildings do not have MERV 13 filters; the MLC has a natural filtration as part of its Leadership in Energy and Environmental Design (LEED) designation. At Foothill there are two portable buildings near the Krause Center for Innovation (KCI) building that do not have MERV 13 filters. At the Sunnyvale Education Center half the building has MERV 13 filters and the other half utilizes outdoor air for a natural ventilation.
- At the Foothill campus, UV-C lights have been installed within mechanical units wherever
possible. This has been shown to assist in the reduction of viruses. Unfortunately,
this process is not compatible with De Anza campus mechanical units.
- Facilities is investigating other technologies that may provide further air cleaning, such as a process called needlepoint bipolar ionization technology (NBPI). In this process, equipment installed in the mechanical unit releases ions. The theory is that the ions will attract particulates, which become larger and more easily filtered out.
Facilities and the campuses are providing individual free-standing air purifiers to provide additional ventilation for buildings and spaces that do not have windows that open; air purifiers should not be used with open doors and windows. The size of the air purifier depends on the square footage of the room space. These units are equipped with HEPA filters, or the equivalent, which need to be changed periodically, typically once a quarter when used on a regular basis. District Facilities and Operations is developing a best practice to maintain these air purifiers.
Q. What kinds of testing are being done on HVAC systems for campus and district facilities, including Sunnyvale? When will the testing be completed? What has been done for the air ducts and air quality in the offices?
A. The district has a heating, ventilation and air conditioning (HVAC) team that regularly inspects and maintains the buildings’ mechanical HVAC units at all district locations. They are tasked with making sure that a) the units are running at optimum levels, b) the mechanical unit dampers are open as wide as possible to bring in outside air, and c) filters are changed on a regular basis, at least three times a year.
At all locations throughout the district, lower-grade air filters have now been replaced with hospital grade MERV 13 filters, which are among those rated most effective in trapping airborne particles.
On the Foothill campus, an ultraviolet (UV) system is part of the HVAC system and works to reduce viruses. The HVAC team monitors this system to ensure that it is operating correctly. Though the De Anza campus does not have a UV system currently installed due to the decentralized nature of the campus HVAC system, both this type of system and a needlepoint bipolar ionization system (NBPI) are being evaluated for use at De Anza. NBPI system are designed to attract particulates, which become larger and are more easily filtered out.
In addition, district and campus personnel are providing individual free-standing air purifiers to provide additional ventilation for buildings and spaces that do not have windows that open; air purifiers should not be used with open doors and windows. The size of the air purifier depends on the square footage of the room space. These units are equipped with HEPA filters, or the equivalent, which need to be changed periodically, typically once a quarter when used on a regular basis. District Facilities and Operations is developing a best practice to maintain these air purifiers.
Q. Does each room have its own MERV 13 filter?
A. No, MERV 13 filters are installed within the HVAC system that services and supports the building and its associated rooms.
Q. Will portable air conditioning units help prevent the spread of Covid-19?
A. Portable air conditioning units do not prevent the spread of Covid-19. Most units recirculate indoor air without filtering it.