Let’s start with a nod to your home’s central heating and/or air conditioning system. Easily one of the greatest and most unappreciated innovations in the last 100 years, it keeps you warm on cold days and efficiently cools off your home when outdoor temperatures are unbearable. 

Like every great innovation, there are a few negative aspects that come along with all the positive benefits. For example, the typical HVAC system can diminish indoor air quality by accelerating the spread of indoor contaminants throughout your home. Those “hyper-allergenic” filters available on Amazon and at your local hardware store definitely help to reduce the negative air quality impact on your home (to some extent); however, since most HVAC systems use only 1-inch-thick filters, which provide mediocre-to-poor performance when it comes to filtering the micro-particles that are the most harmful to our health, most homes are left unprotected against sub-micron contaminants. These tiny particles often fly under our immune systems’ radar, and an ever-growing number of studies suggest they can lead to long-term, chronic lung-related health conditions.  

What does MERV 16 mean?

MERV, which is an acronym for Minimum Efficiency Reporting Value, is a rating system that was developed by ASHRAE (the American Society of Heating, Refrigerating and Air-Conditioning Engineers). A filter is sent to an ASHRAE lab, and its efficiency is tested against aerosols at three different size ranges (E1, E2, and E3). The higher the value, the more efficient the filter is at filtering airborne contaminants. While many traditional, best-selling filters offer adequate efficiency for the E2 (1-3 micrometers) and E3 (3-10 micrometers) groups, which include various allergens and household dust, their performance dramatically falls short for the E1 group (0.3-1 micrometers). Why is the E1 particle group so important? Here are just a few of the reasons: 

1. Smaller particles take longer to settle on the floor, which means that they are more likely to be inhaled into our lungs. Sub-micron contaminants can linger in the air for days!
2. Unlike larger contaminants such as allergens, our body doesn’t warn us against sub-micron contaminants. That fancy $300 AQI monitor you bought? That won’t do much since it can only detect 2.5 micron (or larger) particles. Asbestos fibers are a common example of an “under the radar” air pollutant. Those who become chronically ill due to ongoing exposure to asbestos often have no idea that something is terribly wrong until it is too late to do anything about it. Some research suggests that continuous exposure to wildfire smoke is just as bad.
3. There are considerably more sub-micron pollutants in the air than there are larger particles.

Unlike traditional filters, which are typically capped at around 50% efficiency at the sub-micron level, some MERV 16 filters offer more than 95% efficiency, which puts them on par with a true HEPA filter, which is used in cleanrooms, medical facilities, and air purifiers. 

 Image Source Link: MERV Rating Chart

Image Source Link: MERV Rating Chart

Is MERV 16 better than MERV 13?

As for their filtration efficiency, MERV 13 filters work great when it comes to household dust and some allergens; however, their performance falls short at the sub-micron level. In most cases, a MERV 16 furnace and AC filter would offer double the efficiency of a MERV 13 filter at the sub-micron level.

Is MERV 16 too restrictive?

A common misconception is that the higher the MERV rating, the more restrictive the filter is. In reality, the resistance of a filter depends on several factors that are unrelated to its MERV rating. As an example, some MERV 16 furnace and AC filters are rated at half (or less) the resistance of MERV 8 air filters due to their design (larger surface area, which reduces face velocity and pressure drop, the use of media with higher permeability, etc.).

Initial resistance, also known as pressure drop, determines the amount of strain a clean air filter applies on your furnace or air conditioner’s fan. The higher the resistance, the harder and longer your system must work to heat or cool your home. For some systems, excessive resistance can be detrimental to the health of your equipment, and in some cases, to the health of your home. This is why it’s important to keep track of the pressure drop rating when choosing a filter. In fact, an excessive pressure drop is a key reason why traditional filters are capped at a lower MERV rating. Generally speaking, there is a direct correlation between pressure drop and MERV rating (the higher the MERV, the higher the pressure drop) when the filters being compared share the same dimensions, depth, and pleat architecture. 

Can my furnace or air conditioner handle a MERV 16 filter?

All central air furnaces and air conditioning units can handle MERV 16 filters; however, since MERV 16 filters tend to be quite deep when compared to traditional filters, the installation of a dedicated aftermarket housing is required, which is not always feasible. Some furnaces and air handling units are located in a tight space where adding another bulky component such as an aftermarket filter housing, or a humidifier, is impossible, or at least not cost-effective.

Do I need a MERV 16 filter?

Since a higher MERV rating correlates to a lower particle count, the higher the MERV rating the better. If you can afford one, and your furnace or AC can take a MERV 16 filter, there is no reason not to get one—especially if your home was built prior to the 1980s, when the use of asbestos-containing building material was quite common, or if you live in a state prone to wildfires. The performance of a MERV 16 filter is meaningfully higher at the sub-micron level.

Is HEPA better than MERV 16?

HEPA filters are 99.97% efficient at capturing particles with a diameter of 0.3 microns, while most MERV 16 filters offer efficiencies of about 95%. However, the resistance of HEPA filters is usually much higher (compared to MERV 16 filters), which makes them too restrictive for your furnace even when the filters are brand new. Add some dust into the mix, and that resistance climbs dramatically. In other words, HEPA filters are energy hogs from the get-go, and they clog much faster than most MERV 16 filters. That usually adds up to monthly replacement costs of $100-$200 filter. Yikes!

Does MERV 16 filter wildfire smoke?

As part of the Clean Air Act, the EPA has set national ambient air quality standards (NAAQS) for six principal pollutants, including three pollutants that may be of concern during wildfire smoke events. Those are: particulate matter (PM10 and PM2.5), ground level ozone (O3), and carbon monoxide (CO). The principal pollutant of concern to public health is particulate matter. Particulate matter is a generic term for particles suspended in the air (solid matter or droplets). The smaller and lighter the particle, the longer it can linger in the air, and the more likely it is to get into our lungs, or worse, into our bloodstream.

Particles from smoke tend to be very small, with a size range close to the wavelength of visible light (0.4-0.7 micrometer), and as of now, MERV 16 filters offer best-in-class performance at that particle size range. As for CO and ozone, the MERV rating of a filter is irrelevant as filtering those pollutants requires a different strategy altogether.

Best MERV 16 filter for your home’s heating and air conditioning system

Breathable Intake CAL series

FilterStudy Score: 9.7/10

Efficiency at 0.3–1 micrometer: About 96%-97%

Initial resistance/pressure drop (CAL20): About 0.11 @ 1,280 cfm

Replacement frequency: About once a year

The CAL16 and CAL 20 MERV 16 filters were mainly designed for California but would work just as well in other states where frequent wildfires are a concern. It includes a carbon layer that helps with absorbing VOCs, plus it offers the highest efficiency we have tested at the 0.4–0.7 micrometer particle size range (extremely important during a wildfire). On top of that, it provides both a high loading capacity (about four times the capacity of most furnace filters) and a low resistance/pressure drop (nearly half the pressure drop of most furnace filters). It’s a beast of a filter! The only issue with this filter is that due to its massive size (five times the thickness of most filters), it requires a very specific filter housing, and installing that housing isn’t a DYI project. You’ll need to hire a pro to modify your return duct to be compatible with this filter, which can cost anywhere between $600-$1,200. The filter costs about $100, which is considered high for an HVAC filter; however, in the long run, it provides better ROI due to its low resistance and higher loading capacity.

Pros:

• Highest efficiency at 0.3–1 micron
• Durable
• Extra wildfire smoke protection
• Low resistance (more energy-efficient and less wear and tear on your HVAC system)
• Low replacement frequency (about once a year)

Cons:

• Requires a dedicated housing
• Housing installation is not a DIY project (requires professional installation)

Lennox X6675

FilterStudy Score: 9.4/10

Efficiency at 0.3–1 micrometer: About 95%

Initial resistance/pressure drop: About 0.15 @ 1,280 cfm

Replacement frequency: About once a year

Pros:

• High efficiency at 0.3–1 micron
• Low resistance (more energy-efficient and less wear and tear on your HVAC system)
• Low replacement frequency (about once a year)

Cons:

• Somewhat fragile construction, making it more likely to tear while installing/removing
• Requires a dedicated housing
• Housing is not a DIY project (requires professional installation)

The Lennox X6675 is a general-purpose MERV 16 filter. As with the CAL series, it includes a carbon layer that helps with absorbing VOCs, plus it offers high efficiency for the E1 group. It provides both a high loading capacity (about four times the capacity of most furnace filters) and a relatively low resistance/pressure drop. Our main gripe with it is its poor construction; the frame fell apart when we installed it (it used to be my filter of choice). 

AprilAire 516

FilterStudy Score: Pending

Efficiency at 0.3–1 micrometer: About 96%

Initial resistance/pressure drop: NA

Replacement frequency: Once every six months

Pros:

• High efficiency at 0.3–1 micron

Cons:

• Expensive
• Trickier to install, which could potentially lead to a bypass around the filter
• Requires a dedicated housing that does not support standard filter sizes
• Housing installation is not a DIY project (requires professional installation)
• Bi-annual replacement

The AprilAire 516 is the latest MERV 16 offering by AprilAire. It’s a great MERV 16 filter assuming you actually have an AprilAire filter housing. Unlike Breathable Intake and Lennox, AprilAire uses proprietary dimensions for their filters that would not work on standard 4- to 5-inch filter cabinets. What don’t we like about it? Bi-annual replacements are more of a pain in the you-know-what than annual replacement (as with the other filters listed on this list), plus, their frameless filter design is a bit trickier to install and is more likely to allow for a bypass of air around the filter. In other words, if installed incorrectly, you’re stuck with a very expensive MERV 13 filter.

IQAir Perfect 16

Efficiency at 0.3–1 micrometer: About 96%

Initial resistance/pressure drop: About 0.22 @ 1,400 cfm

Replacement frequency: About once a year

IQAir is a well-known brand for standalone air purifiers, and the IQAir Perfect 16 is their HVAC offering. It’s a well-constructed system with an M-configuration (four filters zigzagged), which allows for air to flow more easily through the filter. Its performance is very similar to that of our top pick; however, it costs six to eight times as much. At an MSRP of $2,500 to over $3,000 (or more) and three times the cost for every filter replacement (about $300), it’s hard to recommend this option as our top pick. Otherwise, there is almost no difference between this system and the Breathable Intake system.

Pros:

• Highest efficiency at 0.4–0.7 micron
• Durable
• Low resistance (more energy-efficient and less wear and tear on your HVAC system)
• Low replacement frequency (about once a year)

Cons:

• Extremely expensive
• Requires a dedicated housing
• Installing the housing is not a DIY project (requires professional installation)