What MERV Rating Should I Use?

Although your heating and cooling system does its job well, it needs a little bit of help when it comes to keeping the air clean. However, there are lots of choices when it comes to air filters, so which one should you choose?

What Are MERV Ratings?

As air is pulled through the vents and distributed to various rooms in your home, it passes through an air filter. This air filter helps to remove some larger contaminants from the air, such as dust, mold spores, pollen, carpet fibers and more. The MERV rating of your air filter determines how well it filters out particles. The higher the MERV, the smaller the particles your filter can remove from the air.

MERV ratings can be as low as 1 and as high as 16:

An air filter with a MERV of 4 will remove particles larger than 10.0 pm, including pollen, dust mites, sanding dust, spray paint dust, and carpet and textile fibers.

A MERV of 8, the minimum recommendation for commercial buildings, particles of 3.0 to 10.0 pm are filtered, including cement dust, dusting aids, hairspray and mold spores.

Choosing an Air Filter

Now that you’ve got a basic understanding of MERV ratings, you can choose an air filter for your central heating and cooling system. Of course, the rating you opt for depends on how much you value indoor air quality.

At the very least, you should have an air filter with a MERV of 4 or higher. This provides minimal filtration for residential buildings. If you want to filter out more contaminants—especially if you’re worried about mold spores—you should get a filter with a MERV of at least 8.

Conversely, you probably don’t need to go any higher than a 12. A high-quality air filter with a MERV of 12 will filter out the milled flower, lead dust, humidifier dust, and even legionella bacteria. If you’re looking for great air quality in a residential home, these filters are a great choice.

Replacing Air Filters

Even though Columbia, SC, has pretty good air quality, your filter still needs to be replaced every now and then. The general rule is to replace it at least every three months, although that depends on a number of factors. If you’d rather not undertake this job yourself, you can always contact a professional for AC/heating maintenance.