MERV Ratings Explained: Choosing the Right Air Filter for Your Home

Introduction

As an HVAC tech, I can’t tell you how many times I’ve walked into a home with a struggling furnace or central air system, only to find that the homeowner either picked the wrong air filter or didn’t realize how important the right one is. One of the most common questions I get is, "What MERV rating should I use?" Choosing the right MERV rating isn’t just about air quality—it directly affects your HVAC system’s efficiency, longevity, and performance. Let’s break down MERV ratings and help you find the right balance between filtration and airflow.

What is a MERV Rating?

MERV stands for Minimum Efficiency Reporting Value. It’s a standardized rating that tells you how well an air filter traps airborne particles. The scale runs from MERV 1 to MERV 20, with higher numbers indicating finer filtration.

Think of it like a strainer. A lower-rated filter is like a colander with big holes—debris passes through easily. A higher-rated filter is like a fine mesh strainer—catching even tiny particles. But, the finer the filter, the harder it is for air to pass through. If your system isn’t designed for high-MERV filters, you could end up restricting airflow and overworking your HVAC unit.

Breaking Down MERV Ratings

Let’s look at what each range actually means for your home and HVAC system:

• MERV 1-4:

• Captures large particles like dust, lint, and pollen.

• Provides minimal filtration—better than nothing but not great for indoor air quality.

• Used in older systems or places where filtration isn’t a priority.

• MERV 5-8:

• Catches mold spores, pet dander, and dust mites.

• Standard for most homes—balances good airflow with decent filtration.

• Great for homeowners without allergies or respiratory issues.

• MERV 9-12:

• Traps fine dust, lead dust, and some bacteria.

• A solid choice for homes with pets, allergy sufferers, or high indoor air quality concerns.

• Can slightly restrict airflow in older HVAC systems.

• MERV 13-16:

• Blocks smoke, bacteria, and even some viruses.

• Typically used in hospitals, clean rooms, or high-end residential applications.

• May require HVAC upgrades to handle the restricted airflow.

• MERV 17-20:

• Captures the smallest particles, including airborne viruses.

• Used in medical facilities and labs.

• Not practical for residential HVAC systems.

Choosing the Right MERV Rating for Your Home

Now that you know the range, how do you pick the right one? Here’s what to consider:

1. What’s Your HVAC System Capable Of?

• Before jumping to a high-MERV filter, check your system’s manual or ask an HVAC pro (like me!). If your system isn’t designed for higher ratings, you will restrict airflow, causing all components of your unit to work harder and wear out faster.

2. Do You Have Pets or Allergies?

• If you have pets, go for at least MERV 8-12 to help control pet dander.

• If you or someone in your home has allergies, MERV 11-13 is a better option to filter out pollen, mold spores, and fine dust.

3. Do You Want to Improve Indoor Air Quality?

• If you live in a high-pollution area or have respiratory concerns, MERV 13+ can help filter out smoke and airborne bacteria. Just make sure your HVAC system can handle it.

4. How Often Will You Change the Filter?

• Higher MERV filters trap more particles, meaning they clog up faster. If you’re not replacing them regularly, your system will suffer. If you’re bad at remembering, stick with MERV 8-12 and change it every 1-3 months. If you are bad at remembering you can always sign-up for our scheduled deliveries and you wont have to worry about forgetting to change your air filter anymore. We have a Quiz you can take to find the right schedule for your household.

The Common Mistakes Homeowners Make When Choosing Their MERV Rating.

I’ve seen it all when it comes to air filters. Here are the top mistakes you should avoid:

• Choosing the Highest MERV Rating Without Checking Compatibility: More filtration isn’t always better if it chokes your HVAC system. Most filter companies are happy to push the highest rated filter on you because they are more expensive. We do not do that here, I rarely recommend going over a MERV 8. Unless you have bad allergies, It's just not worth the strain it puts on your HVAC system and the added maintenance because as we’ve covered above the higher rated your filter is the faster it clogs.

• Not Changing the Filter Regularly: Even the best filter won’t work if it’s clogged. I constantly go on service calls that never would have happened if the customer had just changed their air filter. It’s just so easy to forget, I am an HVAC tech and I still forget every once in a while. But it's unfortunate because now the customer ends up spending at least $100 extra for the service call and ends up having to buy a new filter anyways.

• Buying the Wrong Size: Always check your system’s manual or measure your current filter before buying a new one.

• Thinking All Filters Are the Same: A cheap fiberglass filter might save you money upfront, but it won’t protect your system like a good pleated filter will.

Final Thoughts

Your air filter does more than just clean the air—it protects your HVAC system and keeps your home comfortable. The key is finding the right balance between filtration and airflow. If you’re not sure which MERV rating is best for your home, reach out to a professional (that’s me!) before making the switch. And if you want to make things even easier, consider signing up for an air filter subscription service so you never forget to replace it.

Need help figuring out the best filter for your HVAC system and how often you should be changing it take our quiz! LINK QUIZ