Indoor Air Quality & Filters Guide

Your HVAC system does more than heat and cool — it’s the front line for keeping your home’s air clean and healthy. Let’s look at how filters, ventilation, and air quality accessories work together to protect your comfort.

What Is Indoor Air Quality (IAQ)?

Indoor Air Quality refers to the cleanliness, humidity, and freshness of the air you breathe indoors. Dust, pet dander, smoke, and even cleaning products can pollute your air. A well-maintained HVAC system helps filter, circulate, and refresh that air constantly.

Common Sources of Poor Air Quality

Dust and pollen buildup in ducts or vents.
Mold growth from high humidity or condensation.
Volatile organic compounds (VOCs) from paints and cleaners.
Pet dander, smoke, and lingering odors.

How HVAC Filters Work

Air filters capture airborne particles before they enter your HVAC system. They protect both your equipment and your lungs. Over time, clogged filters restrict airflow, increasing energy use and reducing comfort.

Understanding MERV Ratings

MERV (Minimum Efficiency Reporting Value) tells you how effective a filter is at capturing particles. Ratings range from 1–20, but higher isn’t always better for every system.

MERV Rating	Captures	Best For
1–4	Dust, lint, large particles	Older systems or basic protection
5–8	Pollen, pet dander, mold spores	Typical residential systems
9–12	Fine dust, smoke, bacteria	Homes needing better IAQ
13–16	Viruses, allergens, fine particulates	Medical-grade or high-efficiency systems

Choosing the Right Filter

Check your system’s specs — high-MERV filters can restrict airflow if your blower isn’t designed for them.
Most homes do best with MERV 8–11 filters for a balance of filtration and airflow.
Replace disposable filters every 60–90 days, or wash reusable ones regularly.

Beyond Filters — IAQ Accessories

UV lights: Kill bacteria and mold inside air handlers or coils.
Whole-home humidifiers/dehumidifiers: Maintain ideal humidity (30–50%).
Energy Recovery Ventilators (ERVs): Bring in fresh air without losing heating or cooling.
Electronic air cleaners: Use ionization to capture ultra-fine particles.

Simple Ways to Improve Air Quality

Replace filters regularly.
Keep return vents open and unobstructed.
Vacuum ducts and vents periodically.
Use low-VOC cleaning products and paints.
Run your system’s fan periodically to circulate air.

FAQ

What MERV rating should I use for my home?

Most homes perform best with MERV 8–11 filters. Higher ratings capture more particles but may restrict airflow if your system isn’t designed for them.

How often should I replace my HVAC filter?

Change disposable filters every 60–90 days — or monthly if you have pets, allergies, or high dust levels. Wash reusable filters according to the manufacturer’s instructions.

Shop the basics:
Filters · Air Quality Accessories · UV Lights