Do you need filtration, ventilation, or dehumidification?

Name the problem before comparing devices

Dust, cooking pollutants, stale air, and high humidity can all prompt a search for better indoor air. They do not all call for the same equipment. Begin with the source of the problem, then decide whether you need particle removal, outdoor-air exchange, moisture removal, or a combination.

EPA's guide to air cleaners treats filtration as a supplement to source control and ventilation. An air cleaner does not remove every pollutant. A filter change also does not repair a wet building material or an exhaust duct that terminates in the wrong place.

guide to air cleaners · Source checked 2026-09-07

Use this comparison to organize a quote

The table describes the main job of each approach. Product details and installation determine actual performance.

Ask each bidder to identify the row their proposal addresses. If the household has several problems, ask which remain outside the proposed scope.

Choose filtration around the room or HVAC system

For a portable particle cleaner, compare the room size and clean-air delivery at a fan setting you can tolerate. For central filtration, have the filter cabinet, fit, maintenance access, and airflow requirements considered together. A filter that air bypasses is not doing its intended job.

PNNL's filter guidance distinguishes particle capture from pressure drop. A MERV rating does not by itself establish whether a filter is suitable for your equipment. Ask for a compatible specification and replacement instructions. For region-specific dust concerns, our Valley fever and air-filter guide covers that separate topic.

filter guidance · Source checked 2026-09-07

Understand what an ERV actually recovers

An energy-recovery ventilator exchanges outdoor and indoor air while transferring some heat and moisture between the air streams. DOE's ERV explainer describes this recovery function. It reduces part of the conditioning burden associated with ventilation; it does not turn outdoor air into an unlimited source of dry air.

In humid weather, an ERV can reduce the moisture arriving with ventilation compared with bringing in the same outdoor air without recovery. Moisture can still enter. In winter, retaining some indoor moisture can be useful, but a house with excessive moisture or cold surfaces may need a different operating response. Ask how the selected unit and controls suit your climate and home.

ERV explainer · Source checked 2026-09-07

An ERV is not a substitute for a dehumidifier

These devices solve different tasks. If the home needs water vapor actively removed while cooling demand is low, ask whether dedicated dehumidification is appropriate. Do not buy an ERV on the promise that the name “energy recovery” means it will hold a humidity setpoint.

ENERGY STAR's dehumidifier guidance covers water removal, humidistats, drainage, and the warm air these appliances release. Ask where the collected water goes, where the unit's heat ends up, and how it will be maintained. If the house is already cool and clammy, use our humidity diagnosis guide to prepare observations before selecting equipment.

dehumidifier guidance · Source checked 2026-09-07

Ask how ventilation will be verified

A proposal should identify where outdoor air enters, where exhaust leaves, which rooms are served, and how airflow is controlled. Ask for commissioning measurements and an explanation of normal, boost, and seasonal settings. Include filter replacement and access to the equipment in the walkthrough.

Discuss outdoor smoke or pollution events with the installer rather than assuming that more outdoor air is always better. Also identify fuel-burning appliances so pressure effects can be evaluated. The goal is a planned ventilation arrangement that accounts for the whole home, with clear operating instructions for the household.

Bring a problem list to the assessment

Write one line for each concern: where it happens, when it happens, and what you have observed. Separate a persistent odor from visible dust, high humidity readings, or condensation. List existing filters, exhaust fans, ventilation equipment, and dehumidifiers if known.

Then ask: “What is the source, what will this device change, and how will we check the result?” That question makes competing proposals easier to compare. Request an indoor-air-quality inspection when the source or appropriate combination of measures is unclear.