What does the Merv number mean on air filters?

What kind of filter should I use in my home HVAC system to help protect my family from COVID-19? Minimum Efficiency Reporting Values, or MERV, reports a filter’s ability to capture particles. Filters with MERV-13 or higher ratings can trap smaller particles, including viruses.

As a general rule, residences do not use higher than MERV 8 filters. We do recommend that everyone uses filters that have at least an 8 MERV rating. These filters will remove the majority of pollutants from your indoor air. … MERV 13 to 16 ratings are usually reserved for filters for labs, hospitals, and operating rooms.

One factor to consider is air flow through the system. … In some cases, using an air filter that is too restrictive for your system may cause low air flow problems as well. MERV 13 is the highest MERV value safe for residential furnaces; the higher ratings are used primarily in commercial units.

A filter with a MERV rating of 13 catches more contaminants and could be considered “better” than a MERV 8 filter. … A MERV 8 filter is best for New Jersey homeowners who are simply trying to keep their HVAC system healthy and clean and don’t want to spend too much on a filter.

When used properly, air cleaners and HVAC filters can help reduce airborne contaminants including viruses in a building or small space. By itself, air cleaning or filtration is not enough to protect people from COVID-19.

Oct. 11, 2021 — A combination of HEPA filters and UV light was effective in reducing airborne COVID particles from the air of hospitals in the first test of its kind, researchers reported.

MERV 11 rated air filters have a filtration efficiency of a little over 90%, making them highly efficient. MERV 11 furnace filters effectively trap pollen, dust, lint, dust mites, and mold, along with smoke, pet dander, smog, auto emissions, bacteria, and other such fine particles.

MERV stands for Minimum Efficiency Reporting Value, and it’s used to tell you how well an air filter can catch particles in your home’s air. The higher the MERV rating, the more efficient the air filter is at catching harmful pollutants in your home’s air.

The ideal MERV filters for both air filtering and furnace efficiency are 7-13, experts say. These filters can be used without any modifications to your equipment. Your system may handle MERV 14-16 with no discernable stress.

Filters within a MERV rating of 17-20 are almost never necessary in a residential home. A MERV rating of 13-16 is considered hospital level air quality, so it is unlikely your home needs any more than that.

MERV 13 air filters are the highest-rated air filters for home use. Any air filter with a rating higher than 13 will restrict air flow to the point of which could cause damage to your HVAC system, resulting in an added expense to fix it.

For Merv 8, 11 and 13 filters, we recommend that you change your filter at least every 3 months, however changing your filter every 2 months provides better filtration which provides healthier and cleaner air in your home.

In most households, a MERV 11 filter provides enough purification to keep the home healthy. However, if someone in your home suffers from allergies, you probably want to go with a MERV 13. This can be pet allergies, pollen allergies, or even allergies to mold and dust.

Luckily, MERV 11-rated filters handle those particles — such as pet hair and dust mites — with ease. … MERV 12 filters trap 80 to 89 percent of average particles of 1.0 to 3.0 microns, with an average particle size efficiency of 90 percent or better.

A MERV 11 rated furnace filter can trap the majority of harmful contaminants that are present in the air. … A MERV 13 filter is capable of filtering out all particle impurities like dust, lint, pollen, mold, dust mites, pet dander, smog, and smoke. On top of this, it can also trap bacteria and viruses.

Transmission of COVID-19 from inhalation of virus in the air can occur at distances greater than six feet. Particles from an infected person can move throughout an entire room or indoor space. The particles can also linger in the air after a person has left the room – they can remain airborne for hours in some cases.

But if a HEPA system is run over a period of time, it can take out a big chunk of viruses — somewhere in the high ninetieth percentile (99.94 to 99.97%). And long enough exposure to the UV light in an air purifying device can disable some viruses, including COVID-19.

Placing your purifier near a window or close to a doorway is typically your best bet. Another reason to place purifiers near areas with a lot of airflow is that moving air has enough energy to lift dust, mold, and many other particles, which it can then distribute around your house.

The UV lights in air purifiers aren’t powerful enough to kill all viruses in one pass. On the other hand, HEPA filters are great at capturing viruses. Data shows they can capture over 99.9% of viruses in a single pass.

How safe are UV purifiers? It’s questionable. The biggest issue with UV purifiers is that they emit varying levels of ozone. Even very small amounts of ozone in the air may result in chest pain, coughing, shortness of breath, and throat irritation.

When you think about air purification, most think of HEPA filters. … UV-C light, one of three types of ultraviolet light, is commonly used in air purification. When properly utilized, this invisible form of light can safely kill germs, mold, mildew, and in some cases even bacteria and viruses.

MERV 10 – MERV 12 filters remove most 1.0 to 3.0 micron particles plus bigger ones. These include all those listed under MERV 8 filters plus pet dander, bacteria, most smoke/smog particles and most auto emission particles. MERV 13 – MERV 16 filters remove most . 3 – 1.0 micron particles plus bigger ones.

The basic recommendation for furnace filters replacement is every 3-4 months for MERV 8, every 6 months MERV 10 and 11 and every year for MERV 16. There are other several factors to consider when determining when to change your home air filter.

MERV RatingAverage Particle Size Efficiency in Microns101.0 – 3.0 50% – 64.9%, 3.0 – 10.0 85% or greater121.0 – 3.0 80% – 89.9%, 3.0 – 10.0 90% or greater140.3 – 1.0 75% – 84%, 1.0 – 3.0 90% or greater160.3 – 1.0 75% or greater

A filter with a MERV rating of around 10 to 12 is sufficient to remove most allergy-causing particles from your home’s air. Most air filters that are able to remove common allergens will have the word “allergy” or “allergen” on their packaging.

For residential furnaces, filters range from 4 to 12 on the MERV scale. … If your family has health or allergy issues, then you may want to look for a high-efficiency filter that’s MERV 11 or higher.

We advise buying no less than a MERV 13 if the system allows for it.

The short answer is that it can, but it’s not really an issue except under extreme circumstances. Most modern HVAC systems have no problem working with higher MERV filters, which is why millions of homeowners depend on them.

MERV 14 is too strong for most home HVAC systems. Explore our MERV 13 Titanium filters to find a size that fits your home. … In other words, it’s a measurement showing how small the holes are in the filter. The higher the MERV number, the smaller the holes, and the less that can pass through.

4. What MERV rating does Rheem recommend? Rheem recommends filters of MERV 8 and above. This MERV level is strong enough to remove substances like pollen, dust mites, dust and pet dander from the air.

Your furnace’s owner’s manual will specify the best MERV rating for your furnace, and in general, filters with a MERV rating of 6 through 9 should be changed every 90 days, while those with a MERV rating of 10 through 12 should be changed every 60 days.

MERV-13 filters are engineered to effectively block impurities down to sub-micron levels (. 3 microns) with 99.97% efficiency. These filters offer the highest level of face mask insert filtration available, while maintaining breathability. … Thus, MERV-13 is considered by most to be the optimal face mask filter.

MERV rating 13-16 MERV 13-16 filters are capable of trapping 90% or more of particles in the 1.0-10.0 micron range. MERV 13 will prevent less than 75% of the 0.3-1.0 micron particles from passing through, MERV 14 will get up to 84%, MERV 15 up to 94% and MERV 16 can trap 95% or more of the smallest particles.