Proper HVAC operation and maintaining acceptable Indoor Air Quality (IAQ) in a facility is a collaborative effort between the offices of Educational Facilities and Maintenance and Custodial Services. Alexandria City Public Schools (ACPS) has implemented certain CDC and ASHRAE guidance regarding ventilation to help reduce the risk for exposure to coronavirus.
Schools are designed to ventilate outdoor air throughout the day to reduce the buildup of pollutants and odors by approximately 35 percent outside air. Both the contractor and internal maintenance staff conduct routine and preventative maintenance on interior and exterior of the facilities, mechanical, electrical, HVAC, and plumbing systems – including replacing air filters, deep cleaning and disinfecting throughout. Custodians and building engineers conduct regular complete building checks, to include identifying any areas of potential concern (e.g., areas that collect dust, checking exhaust fans in restrooms for proper operation, etc.).
What general steps have been taken to improve Indoor Air Quality at the facilities?
ACPS HVAC contractor(s), environmental contractor(s) as well as internal staff (MCS and Educational Facilities) continue to improve indoor air quality at our schools by working to mitigate/eliminate sources of potential pollution and/or to reduce their amount of emissions. Specific activities completed include the removal of noted asbestos in certain schools, cleaning /replacing diffusers, changing of filter type to Minimum Efficiency Reporting Value (MERV) in select systems, condenser coil cleaning and the replacement of degraded actuators.
What has been done since school closures to maintain/update HVAC systems?
ACPS has continued with quarterly preventative maintenance activities on all HVAC systems. Preventative maintenance service includes:
Cleaning of condenser coils
Replacement of degraded actuators
Cleaning of diffusers/grills/vent covers
Replacement of diffusers that were stained
Cleaning of Fan Coil Units (FCUs)
Verifying appropriate operation of unit(s) and system components
In addition, we have continued with planned Capital Improvement HVAC projects for FY2021.
Why transition to Minimum Efficiency Reporting Value (MERV) 13 Filters?
MERV 13 filters are effective at controlling airborne bacteria, most tobacco smoke and pollutants released through sneezing or coughing. MERV 13 filters are designed to improve indoor air quality within the space. It is a pleated filter that utilizes an electrostatic charge to remove very fine particles from the air, as well as potential allergens like mold, pet dander, bacteria—even particles that carry viruses. It doesn’t allow mold, fungus, or mildew to grow in the space.
Why not open windows to assist with ventilation?
Some of our schools have older systems and equipment that have to be closely monitored and balanced. It is essential that these systems are balanced to provide clean, filtered air into interior classrooms and other spaces. Any deviation from air volume rates and temperature ranges has an impact across portions of the system and the area that it is serving. Thus, temperatures should be maintained through specific set point ranges to ensure the fans, motors, etc. are keeping up with air flow and outside temperature fluctuations. Based on these noted considerations, we are not recommending opening windows within classrooms/throughout the facility, as this brings in unfiltered air with more particulates, pollens, etc. into the interior spaces and destabilizes the air balance and relative humidity levels. This cross contaminates the filtered and outside air and can elevate moisture levels, increasing the risk of mold growth.
What site-specific improvements have been made to HVAC systems that will assist in ventilation and air flow?
In addition to Preventative Maintenance activities (at all schools), a number of schools have had site-specific repairs or updates since last spring. Please note that some activities are in-progress (i.e. procurement solicitations) and that some schools have had more activity due to the age and/or type of HVAC system. For more details refer to the HVAC FAQ (PDF).
Once back in the facility, how do I report a HVAC or facility- related concern?
If you have a concern, please advise administrative personnel so a work order can be submitted. Please note that a work order must be submitted in order for the concern to be routed to the appropriate office (Educational Facilities and/or Maintenance and Custodial Services).