When you’re shopping for a new HVAC air filter, it can get complicated and confusing quickly when you start seeing acronyms and terms like MERV and MPR, along with different numbers on the packaging.
Both ratings measure how effectively a filter captures particles, but choosing the right air filter is about more than just dust control. The right filter can improve the quality of the air you breathe, reduce allergens, and help give you the best performance from your heating and cooling system. Using a filter that is too restrictive for your HVAC system can reduce airflow and place unnecessary strain on your equipment.
So what do the numbers on the filters actually mean? How do you differentiate between the two rating systems, and which air filter is right for your home?
What Are MERV and MPR Ratings?
Even though both MPR and MERV rate the effectiveness of air filters, they are different rating systems. Knowing what the ratings mean for each one will make it much easier to compare different filters and get the right one.
What Is a MERV Rating?
MERV stands for Minimum Efficiency Reporting Value. This rating system was developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers. This rating system is the standard and is most commonly used throughout the HVAC industry.
This rating system is simple. The higher the rating, the smaller the particulates the filter will capture. Residential air filters typically range from MERV 1 to MERV 16, though most fall between MERV 6 and MERV 13.
Lower-rated filters capture only larger particles like dust and lint, while higher-rated filters can trap smaller contaminants, including pollen, pet dander, mold spores, smoke, and certain bacteria.
What Is an MPR Rating?
What does MPR mean? It stands for Microparticle Performance Rating. This is a proprietary rating system that was created by 3M specifically for its Filtrete range of air filters.
The MPR rating indicates how effectively the filter captures microscopic particles and smaller contaminants, like smoke, pet dander, pollen, bacteria, and fine dust particles. All of these can affect your indoor air quality, so filtering them out will result in healthier, cleaner air.
Unlike MERV, MPR ratings are only used on select 3M filters.
Why Are There Two Rating Systems?
While the rating scales are different, both systems measure how well the filters work. Which one you’ll follow depends on whether you’re using the Filtrete line of filters. Knowing about both MPR and MERV ratings helps demystify home air filters, so you know what to look for when shopping for replacements.
MERV vs. MPR: What’s the Difference?
The key difference between MERV and MPR ratings is that MERV is what’s widely used across the HVAC industry, so technicians, manufacturers, and many filter brands use it when making any recommendations for air filters in residential systems. MPR ratings, however, are used only for 3M Filtrete products, which are marketed directly to consumers.
The numbering system can sometimes give a very misleading impression of how good a filter is and it might make them seem very different, even if they’re not. For example, a filter with an MPR rating in the thousands might sound vastly more powerful than a MERV 8 or MERV 11 filter, but in reality, they aren’t that different in terms of their efficacy. They’re just using different scales. When comparing two filters using different rating systems, they may offer similar levels of air filtration even though the ratings make it seem like they’re very far apart.
Is MPR Better Than MERV?
Neither rating system is inherently better than the other. MERV is just more widely recognized across the HVAC industry. However, MPR can be helpful if you’re looking at the specific line of filters that uses it.
Instead of trying to figure out which one is better, what matters more is choosing a filter that provides the right balance between improving your air quality and ensuring your HVAC system gets proper airflow.
How to Choose the Right Air Filter for Your Home
The right level of filtration for your home depends on your indoor air quality goals, HVAC system, and whether anyone in the household has allergies, asthma, or respiratory sensitivities.
The Best Filter for Most Homes
For many Chicagoland homes, a MERV 8 filter, or roughly MPR 600, is enough to keep your air free of dust, pollen, and lint. These filters do a good job of capturing common airborne particles without straining your HVAC system.
The Best Filter for Allergies and Pets
Homes with pets or allergy concerns may need a filter with at least a MERV 11 rating, which roughly corresponds to MPR 1000-1200. These filters are more effective at trapping smaller particles like pet dander, mold spores, and fine dust.
The Best Filter for Asthma, Smoke, and Enhanced Air Quality
For higher levels of filtration, MERV 13 filters can capture very fine particles, including smoke and certain bacteria. These filters are often recommended for households with asthma concerns or poor indoor air quality. However, not all HVAC systems can handle filters this dense.
Can a Filter Be Too Efficient?
One of the most common mistakes when replacing your HVAC filter is buying the highest-rated one without considering what the airflow requirements of your HVAC system are.
Using a filter that’s too dense can restrict airflow if the system can’t get enough airflow. This will eventually cause your system to be less efficient, which can cause inconsistent temperatures in your home, and can lead to you needing to fix your heating system or cooling repairs.
When Do Air Filters Need To Be Replaced?
The rating on the filter doesn’t matter if it is dirty or needs to be replaced. Typically, you should replace your air filter every one to three months. However, if you have pets, allergies, or run your HVAC a lot, you may need to change your filter more often since it will get dirty sooner.
Because of the full range of seasons we experience, HVAC filters in Chicagoland homes can become dirtier faster during peak heating and cooling seasons because the systems are running more often than normal.
If you don’t know what filter rating your HVAC system needs or can handle, consulting an HVAC technician can help you make the right choice. Making an appointment to have your cooling system inspected or your furnace properly maintained can help if you’re noticing airflow issues after upgrading to a higher-rated filter, or if you’re still experiencing indoor air quality issues despite regular filter changes.
Signs It’s Time to Change Your Filter
There are several signs your filter needs to be replaced, including:
- Visible dust and debris buildup
- Reduced airflow from vents
- Increased allergy symptoms indoors
- Higher energy bills
- Excess dust accumulating around the home
Choosing the Right Filter Doesn’t Have to Be Complicated
Air filter ratings can seem overly complicated, but once you understand the scales, they are actually pretty simple. The goal is finding a filter that keeps your air cleaner without making your HVAC system work harder than it should. Instead of only focusing on the number on the package, you should think about your household’s specific needs, whether that means reducing dust, managing allergies, or improving your overall comfort.
The right filter should support both healthy airflow and provide cleaner indoor air. If you are unsure what filtration level is right for your system, the team at Ardmore Fresh Air can help you find the solution that fits your home, your equipment, and your indoor air quality goals.