Winter 2014 Health Link Online

HealthLink Online

Uniting Children, Parents, Caregivers, and Health Professionals

Heating, Ventilation & Humidity

HVAC Air Handler

Properly functioning Heating Ventilation and Air Conditioning (HVAC) systems reduce health problems. They dilute infectious particles in the air, so people in the facility don’t get sick easily. Good ventilation controls odors and exposure to pollutants. A properly functioning HVAC filter removes dust and dirt, keeping the facility cleaner.

Child care facilities should adjust HVAC systems for air quality in winter conditions. The Environmental Protection Agency (EPA) recommends some steps to keep people healthy and cut energy costs too.

  1. Ensure proper ventilation. At least once a year, have a competent HVAC contractor inspect and service the equipment. Make sure the ventilation of your facility meets the standards of American Society of Heating, Refrigerating and Air Conditioning Engineers, ASHRAE Standard 62-2013. For more details about the standard go to
  2. Manage indoor humidity levels as outside temperatures drop. Properly adjusted humidity protects the building structure and its contents. Cold air holds less moisture. In the winter, the HVAC system heats cold outdoor air. The warmed dry air can hold more moisture. It takes moisture from any surface– e.g. from body surfaces. Infection-fighting starts in the moist linings of the nose and throat. When the air is too dry, these usually moist linings get dry, making it easier for infections to get started. Dry noses itch, tempting fingers to poke them. Poking fingers in noses spreads germs and can cause nosebleeds. Prevent infection and nose bleeds by drinking fluids and maintaining proper indoor humidity. Keep indoor humidity between 30% and 50%. For more details, go to
  3. Change HVAC filters on a regular basis in systems that have air handlers. Air filters should have a dust-spot rating between 35% and 80% or a Minimum Efficiency Rating Value (MERV) between 8 and 13.

Look for MERV values or ratings on the packaging of HVAC filters. Choose one that allows the air handler equipment to maintain proper flow. The higher the MERV rating, the more particulates will be filtered and the more resistance to flow. The fan motor power must be powerful enough to push air against the filter’s resistance for proper flow.  Check the air flow from all vents that bring air into the room and those that return air to the system. Make sure that they are not obstructed by furniture or large objects. For more details, go to

EPA Schools, IAQ Connector offers regular updates about how to improve indoor air quality. To receive these updates, contact This email address is being protected from spambots. You need JavaScript enabled to view it..">This email address is being protected from spambots. You need JavaScript enabled to view it..