Mechanical/Electrical/Plumbing Systems HVAC systems
Are there any recommendations on how owners should “mothball” the buildings and how to operate the HVAC systems during the shutdown?
The recommendation is to put building systems in unoccupied mode using the Building Automation System (BVAS). If occupants are allowed in the building on a partial or limited basis during the shutdown, the BAS can then be put in occupied mode temporarily and then returned to unoccupied mode when vacated.
What are the recommendations on how to reoccupy a building? What measures should be taken with HVAC systems to return them to normal operation?
FRES has consulted with ASHRAE and reviewed other relevant recommendations. Based on these inputs, we will perform the following:
- Remove all setbacks modes and return equipment to occupied mode.
- Open outside air intake dampers to maximum position for a minimum of four hours before occupation. While performing this “flush out” mode monitor the systems ensure space temperature and humidity are being maintained.
What is the MERV filter standard on campus and what is the scientific data on those ratings?
ASHRAE Standard 52.2 establishes application guidelines for MERV (Minimum Efficiency Reporting Value) filters. ASHRAE states that filters that are MERV 13 and above are efficient at capturing airborne viruses. The Penn standard for filters stipulates a MERV 8 pre filter and a MERV 14 final filter (MERV 14 is a finer mesh than MERV 13).
Should filters be changed more frequently? How often in Penn changing filters? What are the recommended method of replacement and disposal?
ASHRAE does not recommend filters be changed more frequently. They recommend owners to consider letting the filter load up further than usual to reduce the frequency of filter changes. Penn’s current schedule for filter changes is 3-4 months for MERV 8 filters and 12 to 18 months for MERV 14 filters. The MERV 14 filters are rated to last 24 months. Workers performing filter changes follow EHRS recommendations for Personal Protective Equipment. Filters are sealed in boxes or bags and disposed of in regular trash outside of buildings.
Do ventilation rates in the buildings need to be increased? What are Penn’s air exchange rates for labs, offices and restrooms?
ASHRAE recommends following the current ASHRAE 62 Standard - Ventilation for Acceptable Indoor Air Quality. Penn follows these standards for offices, classrooms, and restrooms. For these types of spaces, the ventilation rates are based on the number or occupants and the square footage of the space. For general lab spaces, the air change rate is set by whichever is the highest for the space: makeup air for fume hoods, 6 air changes per hour rate, or space cooling load; unless prescribed otherwise by EHRS.
ASHRAE does not recommend increasing the ventilation rates in buildings beyond what the HVAC equipment is designed to handle. Increasing ventilation rates can cause a number of problems that can negatively affect comfort in the buildings.
What humidity levels does Penn maintain and what is being recommended for fighting COVID 19?
Penn standards call for the buildings to maintain a max Relative Humidity (RH) of 50% in the summertime. There is no standard from ASHRAE for a minimum RH requirement for winter.
Which air handlers are 100% outside air (OA) and which ones have recirculation or return air?
Penn standards require lab air handlers to be 100% OA. All other air handlers serving classrooms, offices, and all other areas have a certain amount of recirculated air per ASHRAE standards.
Does Penn have UVGI lamps installed in the HVAC equipment?
Penn does not have UVGI lamps installed in HVAC systems, and they are not recommended by EHRS.
Is there any air monitoring planned for the buildings?
Air monitoring is not feasible for viruses like Covid-19. There is not an accepted and validated method for sampling so no air monitoring is planned.
Domestic Water Systems
What are you doing to flush out domestic water systems prior to building reopening?
ASHRAE recommends that domestic water systems be flushed to remove potential contaminants from stagnant water in equipment, piping, and fixtures. This goal shall be achieved by flushing out all domestic hot and cold water systems, including all fixtures, piping mains and branch lines.
What about the purported risk from aerosols generated by toilet flushing? Are toilet seat covers being installed?
There is no guidance from the CDC, WHO or others recommending installation of toilet seat covers for COVID -19 mitigation. The NHS recommends washing your hands often with soap and water, but does not give specific advice about toilet use. However, washing hands carefully after using the toilet is standard hygiene advice.