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What MERV Rating Do I Need and What Does it Mean?
Fresh air is essential to your health and that of your family.
Especially if you were on a stay-at-home lockdown order somewhere in the world since you’re probably working from home much more than before in 2020 and 2021.
You want to make sure you are your family are breathing right.
But what filters should you be using for your HVAC system?
You see it printed on various filters: MERV Rating and a number.
But what do MERV Filter Ratings mean?
We will cover that in a second.
⭐ Your Indoor Air Quality
It’s a well-known researched fact that indoor air quality (IAQ) can be more polluted than outside air.
The EPA gives us a crazy figure of 2 to 5 times more polluted.
Even more interesting, but definitely not healthy, is that the average person spends approximately 90% of their life indoors…
We can only wish that we worked on top of that mountain!
We have written an excellent in-depth article on improving your IAQ, and you can find it here.
To give you some idea of the effects of bad indoor air, here are some symptoms that your indoor air may be polluted:
- Short of breath with little energy expenditure
- You are unable to take deep breaths
- Dryness and irritated eyes
- Frequent headaches
- Sinus Congestion.
These are all symptoms of poor indoor air quality.
In addition, people that suffer from allergies, asthma, and other respiratory problems will suffer more severe symptoms that can be harder to treat if they do not take the proper precautions to improve their IAQ.
One of the easiest ways to improve your IAQ is to maintain your HVAC system and make sure you are using the right filter.
In addition, changing your furnace filter regularly throughout the year is necessary for maintaining good IAQ.
Not only should you pick the correctly rated MERV filter for your home, but you should also pay attention to the quality of the filter.
You will find out very quickly that not all HVAC filters are created equal.
For example, a MERV 16 filter, the highest-rated filter replacement you can purchase, can even filter out viruses.
A higher MERV rating air filter may sound like a great idea, but your Furnace or AC might not be able to handle that, but we will get into that shortly.
So, let’s get into it!
⭐ What does MERV Mean?
MERV stands for Minimum Efficiency Reporting Value. MERV Ratings are a rating system designed by ASHRAE (American Society of Heating, Refrigerating, and Air Conditioning Engineers) to report the effectiveness of air filters.
Filters are rated with a MERV score from 1 to 20, with 20 being the highest.
🛑 NOTE: The higher the MERV value, the greater the percentage of particles captured within the air filter.
🍃 MERV Ratings range from 1 to 20
MERV Rating 1 to 16 are considered HVAC system grade filters suitable for residential HVAC systems, commercial and general hospital use.
MERV 17 to MERV 20 filters are used explicitly in industrial or scientific applications such as surgical operating theaters, clean rooms, and other applications that require absolute cleanliness.
Remember the scene from Independence Day when they visit the aliens in the clean lab? I bet they use MERV 20 filters….
So, what’s the difference between a HEPA and MERV Rating? Not a lot.
HEPA is used to describe MERV Rating filters rated 13 and above. HEPA means High-Efficiency Particulate Air.
That’s the long way of saying it’s a good air filter!
The following gives you an idea of what different MERV rated filters can filter out.
⭐ MERV Filter Ratings Categories
✔️ MERV Rating: MERV 1 to MERV 4.
Typical Applications: Prefilter in commercial buildings, residential furnace filters, and window AC units.
Controls: Pollen, dust mites, sanding dust, textile/carpet fibers.
Particle size: Filters down to 10.0-micron particle size.
✔️ MERV Rating: MERV 5 to MERV 8.
Typical Applications: Pre-filters or final filters, commercial buildings, better residential buildings, industrial workplaces, and paint booth inlets.
Controls: Everything above plus mold spores, dust lint, fabric protector, and cement dust.
Particle size: Filters down to 3.0 to 10.0-micron particle size
✔️ MERV Rating: MERV 9 to MERV 12.
Typical Applications: Pre-Filters or final filters, hospital laboratories, better commercial buildings, and superior residential buildings.
Controls: Everything above plus Legionella, lead dust, humidifier dust, coal dust, and nebulizer dust.
Particle size: Filters down to 1.0 to 3.0-micron particle size
✔️ MERV Rating: MERV 13 to MERV 16.
Typical Applications: Final filters, general surgery, superior commercial buildings, hospital inpatient care, and smoking lounges.
Controls: Everything above plus bacteria, tobacco smoke, auto fumes, sneeze nuclei, insecticide dust, copier toner, pet dander, and face powder.
Particle size: Filters down to 0.3 to 1.0-micron particle size
✔️ MERV Rating: MERV 17 to MERV 20.
Typical Applications: Final filter, clean rooms, radioactive materials, pharmaceutical manufacturing facilities, carcinogenic materials, and orthopedic surgery rooms.
Controls: Everything above plus virus carriers, carbon dust, sea salt, combustion smoke, radon progeny, odors, and microscopic allergens.
Particle size: Filters down to less than 0.30-micron particle size.
⭐ Types of Air Filters
There is a vast range of different types of filters out there.
Most renters, homeowners, and business owners alike tend to use the cheapest filter they can find.
The problem is that it’s probably not the most effective at increasing your air quality, and your health will suffer from it.
Most HVAC systems, such as furnaces and air conditioners, can accept different filters as long as they are appropriately sized.
The 4 most common residential and light commercial filters are:
- Fiberglass Filters
- Electrostatic Filters
- Washable Filters
- Pleated Filters
The cheapest out of the group and the least effective.
These rely on fiberglass layers to filter out particles from the air before it gets sucked into your HVAC system.
Their low cost directly relates to their performance.
If you pay peanuts, you get monkeys!
Fiberglass is not a great way to filter your air.
While it can trap larger particles, smaller particles will make their way through. Usually have a low MERV rating…
A step up from fiberglass.
These are more effective at trapping smaller particles than fiberglass.
This type of filter uses static electricity to collect large and small particles traveling through the filter.
The good news is electrostatic filters are reusable.
The downside is you need to wash them regularly.
These can be cleaned with water and a mild detergent at least once a month.
These are great at collecting particles in the air but are ineffective against very fine particles such as smoke.
Also, certain types are known to produce ozone, which is not suitable for your health either.
So best to check on the type of filter.
This type can be used to improve your ventilation efficiency and increase air flow by reducing air flow resistance which puts less stress on your HVAC System.
More expensive than fiberglass.
The cheapest in the group.
Similar to the electrostatic air filter, it must be washed regularly.
Fail to do so, and you will reduce both your HVAC efficiency and indoor air quality.
These are common in ductless mini-splits, portable and window air conditioners, and air purifiers.
Did we mention super cheap?
The Rolls Royce of filters.
The most effective at trapping a range of particles from big to small.
The pleats allow for more surface area in the airflow, allowing it to capture more particles.
HEPA filters fall into this category.
HEPA is a type of pleated mechanical filter.
A HEPA filter can theoretically capture at least 99.97% of all dust, pollen, mold, bacteria, and any other airborne particles with a size of 0.3 microns. (EPA reference)
To give you an idea of how small 03 microns is, the average human can see dust or debris down to a size of 25 microns.
Human hair is approximately 70 microns in diameter.
This type of air filter is the most effective and the most expensive.
Depending on the type of HVAC system you have will dictate what size will fit.
If your HVAC system doesn’t allow for this type of air filter and your household has someone who suffers from allergies or asthma, it’s probably best to upgrade your system to accept the thicker sizes.
⭐ So, What MERV Rating Should I Use For My Home or Business?
You might think an air filter with higher MERV ratings would be more beneficial, but in some cases, it isn’t.
The higher the MERV rating, the smaller the hole in the filter for the airflow to pass through.
This can create higher airflow resistance than the system is built to handle, thus making it unusable.
Reducing the airflow in your system can damage the fan in your furnace or AC system and worsen the air quality in your home.
So do your research! Find out the maximum MERV rating allowed in your Furnace or Air Conditioner.
This will ensure an improvement in your IAQ while still maintaining maximum efficiency.
If you can’t find out what MERV to use, call your local HVAC Contractor.
They will help you determine what’s the maximum MERV-rated filter your system can use.
⭐ How to Choose the Right Filter
STEP 1: Check the MERV Rating.
Not all filters are made equal. MERV stands for Minimum Efficiency Reporting Value.
The higher the number, the better the filter. Though your HVAC system may not handle a higher number.
STEP 2: Check the Dimensions
Your new filter should fit correctly. The best way to check is to measure your old one.
You will notice filters may have 2 sizes printed on them: Nominal size and actual size.
⭐ Nominal Size is the rounded size to an industry standard and printed on the filter.
⭐ Actual Size is the true size of the filter. It may be slightly different from the nominal size.
If it’s listed on the filter, it will normally be found under the nominal size in smaller print. If not, the nominal size is correct. You can measure it yourself to confirm the size needed.
STEP 3: Click Order Now!
Click order now and find the right filter. It’s as easy as that.
Phyxter has teamed up with Filters Fast to ensure you get the best filter for your home.
With fast shipping and very competitive pricing coupled with a great selection of filters suited to every need, you will find just the right filter for your home.
Order a single or save money with a multi-pack and put it on auto-ship, so you never have to worry about ordering a filter when you need it again!
Purchase Direct or Check Out Their Amazon Store If You Prefer!
Contact your local HVAC contractor if you’re unsure what filter and MERV ratings are best for your home.
If you live in the Okanagan valley region, give Phyxter Home Services a call.
We are experts in all things HVAC and Indoor Air Quality related.
We offer a range of indoor air quality solutions that can improve the indoor air in your home.
Check out our page on HVAC Services for more information or a free estimate in your area.
We can advise you on what system and MERV ratings you need to provide the best quality air for your family.
Especially if you or a family member suffer from health problems related to or affected by airborne particles.
Dealing with other common AC problems? Check out: Top 18 Common AC Problems and Solutions.