Indoor Air Quality: Air Cleaners and Fresh-Air Ventilation

Updated October 14, 2026 — wording and factual claims reviewed. Original publication date retained.

Why indoor air needs more than one approach

Indoor air quality depends on what enters a building, what is generated inside it, and how air moves through the rooms. Cooking, cleaning, furnishing materials, moisture and outdoor pollution can create different challenges. A useful plan begins by identifying the main sources, reducing emissions where practical, and choosing a ventilation and filtration strategy for the actual building.

Portable air cleaners and fresh-air ventilation have different jobs. A correctly selected air cleaner can reduce some airborne particles in the area it serves, but it does not provide a designed supply of outdoor air. A fresh-air system brings outdoor air into a building and, depending on its configuration, exhausts indoor air. Its filters can reduce specified contaminants in the incoming airstream. Neither approach removes every pollutant or replaces source control.

When a fresh-air system may help

For a home or commercial project, the designer should first determine the outdoor-air requirement under the applicable local rules. Then assess the outdoor air quality, climate, building leakage, room use, duct layout and available maintenance access. A filtered supply may be valuable where opening windows is impractical or outdoor particles are a concern, provided the filter grade and pressure drop suit the selected unit.

Heat-recovery ventilation can transfer part of the heat between outgoing and incoming airstreams. Actual energy performance depends on the specified core, airflow balance, operating conditions and installation. A ventilation unit does not automatically dehumidify a space or remove pollutants released by every indoor source; those needs may require separate controls or equipment.

Regular inspection is as important as equipment selection. Filters, outdoor intake hoods, condensate paths and airflow balance should be checked against the manufacturer's instructions. A dirty filter can reduce airflow; replacing it on the appropriate schedule helps the system perform as designed.

DECETOMair offers ventilation equipment for different residential and commercial applications. To select a model, share the project location, floor plan, required airflow, duct route, intended filtration and operating conditions with our team. We can discuss options, while the final design should follow the applicable code and qualified project review.

For further guidance on source control, ventilation and filtration, see the US EPA guide to air cleaners and air filters in the home.