What is a MERV Rating and Why Should You Care?
Did you know that the air quality in your home can impact your health? Indoor air pollution is a significant environmental health risk, and it's one that's often overlooked. According to the EPA, indoor air can be two to five times more polluted than outdoor air.
That's why understanding the MERV rating on your HVAC unit is so important. MERV ratings help determine how effectively an air filter will remove particles from the air. The higher the number, the more efficient it is at removing particles from the air.
Heard your HVAC technician talking about MERV ratings, but you weren’t sure what it meant? Let's review a little more information to help understand how it relates to your HVAC unit.
What is a MERV Rating?
MERV stands for Minimum Efficiency Reporting Value. It is a number that measures a filter's ability to capture particles from the air passing through it. The higher the MERV rating, the more effective the filter will remove allergens, dust, and pollen from your home's air.
The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) developed the MERV rating system during the 1980s. The ratings range from 1-20, with higher numbers indicating greater efficiency in particle removal. The highest MERV rating can filter out particles as small as 0.3 microns.
So, what do these rating standards have to do with your HVAC?
HVAC professionals use MERV ratings to determine which type of filter should be used in different HVAC systems.
Understanding a MERV Rating
You want your home HVAC system to be as comfortable as possible. To make that happen, you need to ensure that your air filter keeps the air in your home clean and free of allergens and other contaminants.
The average air filter should have a MERV rating of between 8-12. This ensures you're getting enough protection against dust, pollen, and other small particles that can make breathing difficult for those with asthma or allergies.
However, while it might seem like a good idea to go with the highest MERV rating you can find, this isn't always the case. While it's true that high-quality air filters trap more particles, they also have the tendency to clog up your HVAC system faster.
Too high of a MERV rating will lead to an overworked HVAC system and higher energy bills, which nobody wants!
If you want your homes HVAC system to be able to remove more pollutants from your air, you can have additional return air vents installed in your home, or have a centrally located filter installed on to your furnace or air handler, such as the Trane Clean Effects.
MERV Ratings and Their Uses
MERV ratings are a measure of the efficiency of a filter. They can compare filters and help you choose the right one for your needs.
MERV rating 1-7
Air filters with a MERV rating of 1-7 are most often used in larger industrial settings. These filters remove larger particles from the air to protect machinery from dust.
One benefit of a low MERV rating is saving money on energy costs. This is because the filters don't have to work so hard. After all, they only capture larger particles.
However, lower-rated filters aren't suitable for your home because they don't filter out smaller particles like mold spores. As a result, you may save energy, but you risk your health in the process.
MERV Rating 8-13
Most homes have an air filter that falls into this MERV range. The number you opt for will depend on the pollution in your area. It also depends on whether you suffer from allergies or asthma or live with a smoker.
To protect your family from the harmful effects of airborne pollutants —specifically, to reduce their exposure to dust and mold spores — the higher the MERV rating of your air filter, the better.
For instance, a filter rated at MERV 13 can remove particles as small as 0.3–1.0 microns from the air that passes through it. Whereas an 8 only removes particles down to 1 micron.
MERV Rating 14-20
Hospitals and laboratories often use filters with the highest MERV ratings because they're very efficient at removing dust and other contaminants from the air. This helps prevent airborne pathogens from spreading through the facility.
But using a higher MERV rating comes with its drawbacks. First, it uses more energy, leading to higher energy bills. Secondly, they require changing more often as they capture more particles.
If you want to give your family maximum protection, it's best to opt for a HEPA filter.
Does a HEPA Filter Have a MERV Rating?
If you have allergies or asthma, having a HEPA filter in your home is one of the best ways to keep your air clean. These filters are designed to remove 99.97 percent of particles that are 0.3 microns in diameter or larger from the air passing through them.
HEPA filters are so good that they exceed the MERV ratings. But it's advisable to check before purchasing.
Need more help deciding which is the right air filter for your home? Contact the HVAC experts at ProSkill today for more information.