What Does MERV Stand For? What Does MERV Mean?
If you’re new to homeownership or air handlers, you’re probably learning a lot more than you bargained for about the HVAC system, including (but not limited to) what MERV is and what MERV means.
Before I go any further, let’s clarify: MERV stands for Minimum Efficiency Reporting Value. Still, “Minimum Efficiency Reporting Value” doesn’t mean much of anything without any context or further explanation. Let’s fix that.
Air Filtration: A Simple Concept
Most people think air filtration is simple: air filters clean the air by removing dust particles that pass through the HVAC system. Simple enough, right? No different than a water filter or coffee filter, for that matter. Dirty air becomes clean air. For the purposes of understanding MERV, that’s all we need to know.
MERV Rating Answers the Question: “How effective is my air filter?”
You’ve probably asked the question at one time how effective your furnace filter actually is. This is where MERV ratings are useful. Simply stated, a MERV rating assigns a number between 1 and 16 to a filter based on its particle removal efficiency at certain particle sizes. That is the most non-technical way I can summarize it. There’s more to it than that, but you don’t need a technical or engineering lesson on air filtration – that’s not why you’re here.
Basically, you need to know is the following as a homeowner: if you’re looking to buy the best filter for your HVAC unit, the MERV rating tells you how effective the filter is. Period.
Where do MERV Ratings Come From?
Unless it’s classified as a high purity or HEPA filter, all filters possess a MERV rating between 1 and 16. These ratings are not arbitrarily given by a manufacturer or divvied out like candy on Halloween.
With support from the National Air Filtration Association (NAFA), the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) developed a standardized test in the 1990s to determine MERV ratings. These regulated MERV rating standards allow you to objectively compare filters from different manufacturers rather than relying on their own marketing gimmicks.
Don’t get me wrong: this does not imply that all filters with equivalent MERV ratings are equal in value and performance. They are not. But equivalent MERV ratings do imply that filters are similarly efficient in removing dust particulate.
MERV 1-16? I just want a filter for my home!
Those cheap, barely-there blue fiberglass furnace filters you see for $2 at Lowe’s and Home Depot have a MERV rating between 1 and 4. They’re cheap for a reason. These filters barely do anything but protect your furnace from very large particles. That said, you also don’t need a MERV 16 filter in your home. MERV 16 filters are primarily used in commercial applications such as food and beverage manufacturing, hospital cleanrooms, pharmaceutical production, etc. Not only is a MERV 16 filter unnecessary for your home, but it would put a lot of strain on your system – it would block too much of the airflow and your unit would need to work harder, leading to potential breakdowns and costly repairs.
Now that you have an idea of the worst and the best filters out there, let’s look at furnace filters through the lens of what you want and need to install in your home.
What MERV Rating Do You Need In Your Home?
So you want a filter that actually filters out dirt and dust, but you also don’t want a filter that is too efficient because it will put strain on your overall system.
It’s generally accepted that pleated filters ranging from MERV 8 to MERV 13 are suitable for home HVAC units. They effectively scrub the air of particles harmful to both you and your furnace. Here are my tips for choosing the right air filter for you:
- MERV 8 – If you’re living by yourself or just one other person with no pets or allergies, and heavy dust just isn’t a problem in your home, a MERV 8 pleated filter is all you really need.
- MERV 11 – If you have a family or are living with multiple people, have any pets or allergies, or if anyone smokes, a MERV 11 filter will do the trick.
- MERV 13 – If you or your family suffers from major seasonal allergies, spend any time at the gun range or shooting guns (lead dust), or live in a city or area that suffers from smog conditions, you’re best off with a MERV 13 filter.
Again, those are just my tips for what MERV rating you should use in your home. For more information on each MERV rating, click here or ask me below. I’m always happy to help.