HVAC Frequently Asked Questions (FAQ's)

  • Proper HVAC operation and maintaining acceptable Indoor Air Quality (IAQ) in a facility is a collaborative effort between Educational Facilities and Maintenance and Custodial Services offices. ACPS has implemented certain CDC and ASHRAE guidance regarding ventilation to reduce the risk for coronavirus exposure.

    Schools are designed to ventilate outdoor air throughout the day to reduce the buildup of pollutants and odors by approximately 35% outside air. Both 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, including identifying 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?

    Our 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 removing noted asbestos in certain schools, cleaning /replacing diffusers, changing filter type to Minimum Efficiency Reporting Value (MERV) in select systems, condenser coil cleaning, and replacement of degraded actuators.


    • What has been done since school closure to maintain/update HVAC systems?

    ACPS has continued with quarterly preventative maintenance activities on all HVAC systems. Preventative maintenance service includes:

    • Filter Changes
    • Cleaning of condenser coils
    • Replacement of degraded actuators
    • Cleaning of diffusers/grilles/vent covers
    • Replacement of diffusers that were stained
    • Cleaning of Fan Coil Units (FCUs)
    • Verifying appropriate operation of the unit(s) and system components

    Also, we have continued with planned Capital Improvement HVAC projects for FY2021.


    • Why transition to ​Minimum Efficiency Reporting Value​ (​MERV) 13 Filters?
    MERV 13 filters effectively control 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 and 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. These systems must be balanced to provide clean, filtered air into interior classrooms and other spaces. Any deviation from air volume rates and temperature ranges impacts portions of the system and the area that it is serving. Thus, temperatures should be maintained through specific setpoint ranges to ensure the fans, motors, etc., are keeping up with airflow and outside temperature fluctuations. Based on these noted considerations, we are not recommending opening windows within classrooms/throughout the facility. 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 airflow?

    In addition to Preventative Maintenance activities (at all schools), several 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 an HVAC or facility-related concern?

    Please advise your respective administrative personnel so a work order can be submitted if you have a concern. Please note that a work order must be submitted for the concern to be routed to the appropriate office (Educational Facilities and/or Maintenance and Custodial Services).



    Office of Maintenance and Custodial Services
    Office of Educational Facilities 
     Educational Facilities