Chapter 16

Indoor Air Quality: What HVAC Can and Cannot Do

Heating and cooling equipment can support indoor air quality through filtration, ventilation, and moisture control, but no single filter or add-on device solves every indoor-air concern.

Begin with source control. Avoid indoor smoking, use kitchen and bathroom exhaust fans, store chemicals as directed, and fix leaks and dampness. Ventilation can dilute some indoor pollutants, but outdoor air may also bring humidity, pollen, smoke, or other contaminants. Ventilation should be appropriate for the home and climate.

Filtration can capture particles when the filter is correctly selected, installed, and maintained. Ask a qualified HVAC professional which filter efficiency is compatible with your equipment. A filter that is too restrictive may reduce airflow. Portable air cleaners may help in particular rooms when appropriately sized and maintained.

Be cautious about products marketed with sweeping claims such as eliminating all allergens, viruses, odors, or mold. Ask what the device actually removes, what independent testing supports the claim, what byproducts may be produced, and what maintenance is required. The EPA advises focusing on source control, ventilation, and filtration as complementary strategies.

If household members have persistent health symptoms, consult a healthcare professional. An HVAC contractor can evaluate equipment and building conditions but should not diagnose medical problems. For radon, carbon monoxide, mold, or other specific hazards, use the appropriate testing and qualified professionals.