MERV 8 vs MERV 13 Furnace Filters – The Surprising Differences Between Them

When browsing for furnace filters you typically see most filters are rated from MERV 8 to MERV 13. Of course there are still some retailers that carry the low quality fiberglass filters too. But assuming you value a higher level of air quality in your home, you will probably find yourself comparing MERV 8 and MERV 13 filters.

Although prices can vary, you can see that there is a pretty big price difference between the two MERV ratings.

So it begs the question, is it really worth upgrading from MERV 8 to MERV 13? Is there a huge difference between the two?

Well, in order to understand the difference, we must first get acquainted with how the MERV rating scale works.

Understanding MERV Ratings

MERV stands for minimum efficiency reporting value and it is basically a measure of how effective a furnace filter is. Although the scale ranges from MERV 1 to 20, the majority of furnace filter retailers only carry filters between MERV 8 to 13.

To put it short, the higher the rating, the more particles the filter will trap and therefore the higher the quality. The table below breaks down the particle size each MERV rating is capable of filtering.

MERV Rating Particle Size Scale

(NOTE: 1 micrometer is 1000 times smaller than a millimeter)

As you can see from the table, the difference between a MERV 8 and a MERV 13 is ONLY 2 MICROMETERS!

It doesn’t sound like much at all, especially if you consider that 2 micrometers is 0.002 millimeters. Paying a premium for an additional 0.002 milometer of filtration may sound crazy, until you consider how things work at the molecular level.

The Difference That 2 Micrometers Can Make

Not to sound overly dramatic but at the molecular level what may seem like a minuscule difference can actually mean the difference between life and death. (hence why hospitals only choose a certain type of filter, as I will explain later).

Now I don’t want to alarm you, chances are, nothing fatal will happen in your home if you choose a lower MERV filter. However it’s important to understand the limitations of a MERV 8 filter and the benefits of a MERV 13.

What MERV 8 is able to do

MERV 8 filters are great for an average home. It is miles better than fiberglass filters and is still quite reasonably priced.

This type of furnace filter will be able to trap anything larger than 3 micrometers, which is enough to trap the common pollen, dust and debris.

Why MERV 13 makes a huge difference

MERV 13 filters are great for anyone looking for an advanced level of air quality in their homes. There is a reason why many hospitals and other medical facilities use MERV 13 filters.

This type of furnace filter will be able to trap anything larger than 1 micrometer, which effectively traps pet dander, mold spores, car fumes, smoke, bacteria and other microallergens.

Trapping bacteria and microallergens can help prevent various harmful sicknesses and severe allergic reactions. Avoiding these contaminants in the air inside your home may mean vast overall health benefits.

Comparing MERV 8 vs MERV 13

How to determine which is filter is the best for your home

Each household is different and therefore requires a different level of filtration. As mentioned earlier, MERV 8 filters are a great solution for most households, so chances are, you will be just fine with this one.

However, below are a few reasons why you might consider upgrading to a MERV 13.

Allergies – if you suffer from allergies and don’t currently use a MERV 13 filter in your household, we highly recommend giving it a shot. You may end up spending an extra $40 or $50 for a year supply of furnace filters, but its a small cost to help relieve allergy symptoms.

Pets in your home – Another reason to upgrade to a MERV 13 is if you own a pet. Pet dander can have detrimental effects on the air quality in your home and upgrading your filter will definitely help. This is even more important if you have multiple pets in your home.

Smog and construction – If you live in an area with heavy construction, factories or smog, using a MERV 13 filter will ensure that the air inside your home will not be contaminated.

Wildfire smoke – The last reason why it would be a good idea to upgrade to a MERV 13 filter is if you live in or near a wildfire smoke area. Much of Western Canada and US have been affected by the wildfires this year and many of our own customers were affected. They have told us that they have noticed an immediate difference within just a couple hours after installing a MERV 13 filter.

The Final Verdict

What may seem like a minuscule difference (literally, 0.002 millimeters), has drastic effects on the air quality in your home.

We have had several customers tell us that the difference between the two filters was night and day, citing:

  • Improvements in sleep
  • Less headaches
  • Increased energy
  • Overall higher quality of living

As mentioned earlier, it will only cost you an extra $40-$50 a year to upgrade from MERV 8 to MERV 13, and assuming your furnace can handle it, why not give it a shot?

As always, feel free to contact us if you have any questions or need help deciding which filter is right for your home.

What type of furnace filter do you have in your home? Have you ever upgraded MERV ratings? Did you notice a difference? Leave your feedback below!

by purefilters

4 thoughts on “MERV 8 vs MERV 13 Furnace Filters – The Surprising Differences Between Them

  1. Gary says:

    I would be concerned that the furnace blower would be substantially less efficient. It is harder to push large volumes of air through a finer filter. Hence a large home properly sized for HVAC would have been determined by a filtration system of Merv 8 or possibly even old school fiberglass. Now the blower is trying to push through a fine filter, much like a dirty filter gets. So I would ask ‘how much more air flow restriction does this Merv13 have compared to Merv8/

    • purefilters says:

      Hi Gary,

      Thank you for your feedback, appreciate you taking the time to write us. It really depends on the whether the MERV 13 filter is high capacity or standard capacity. High capacity filters (the only kinda we sell) have the ability to capture the fine particles much less air flow restriction compared to low capacity filters. This is because of the nature of the surface area high capacity filters have, designed for better air flow.

      Hope this helps!

      PureFilters Team

  2. Charles says:

    My HVAC recommended a Merv 8 filter as the Merv 13 traps too many fine impurities causing the furnace to work harder and therefore less efficient. I had previously been using a Merv 13 filter.

    • purefilters says:

      Hi Charles,

      Thank you for your feedback, appreciate you taking the time to write us. It really depends on the whether the MERV 13 filter is high capacity or standard capacity. High capacity filters (the only kinda we sell) have the ability to capture the fine particles much less air flow restriction compared to low capacity filters. This is because of the nature of the surface area high capacity filters have, designed for better air flow.

      Did you have a high capacity MERV 13 filter previously?

      Hope this helps!

      PureFilters Team

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