In this article on whole house air purifier reviews we highlight three options available to you.
They are the furnace filter, an installed whole house air cleaner and room air purifiers. It really comes down to your needs and is often a matter of choosing between a whole house vs room air purifier.
In this article we also provide tips, pluses and minuses for each option.
Best for: protecting the HVAC equipment.
What it Filters: Large dust, pet hair, pet dander and mold spores. Not rated to filter any of the smallest airborne particles that trigger asthma or allergies. Typically rated for less than 50% of the larger sized dust particles.
The lower priced air filters you will find at stores like Home Depot or Lowes are made for use with the return air ducts of your cooling or forced-air heating system. While these filters can be marketed as allergy air filters, the primary purpose is to keep your air conditioning system clean of dust so it can run efficiently.
These air filters will often have a MERV rating listed on the packaging. This is a good way to know how efficient the filters are. That means, it gives an indication for the size and percentage of airborne particles that the filter can remove.
The higher the MERV rating the higher the efficiency. If you are looking for asthma or allergy relief you need to remove the smallest particles. That is, to focus on particles less than 1 micron in size and ideally much smaller than that. This is because it is the smallest airborne particles that float in the air the longest. And they are too small to be filtered by your nasal passages so it’s what you breathe into your lungs. So, these are the particles that trigger asthma and allergy symptoms.
The air filters that you can wash and have large openings are in the MERV 1 to 4 range. These are meant to catch the very large pet hair and dust particles. Air filters in this class are rated to remove less than 20% of particles in the 3 to 10 micron size. And 0% of smaller sized particles.
Filters in the MERV 4 to 8 range do a better job with larger sized mold, mold spores, dust mite debris, plus cat and dog dander. They are rated to remove up to 70% of particles in the 3 to 10 micron size but still 0% of the smaller particles.
Filters in the MERV 9 to 12 range begin to remove particles in the 1 to 3 micron size and do a better job in removing pet dander but are not rated to remove any particle less than 1 micron in size.
An issue when you get to the MERV 9+ range is that the air flow resistance is higher. In many cases this causes added stress to your ventilation system since most were not designed to be filtered with a more dense filter. This could result in lower air flow through your HVAC system which causes it to run more. With less air flow you may see a reduction in indoor air quality.
You have the same effect if you delay replacing these filters. While many procrastinate on replacing these filters, often to save money, it turns out you end up spending more in higher electricity bills than if you just replaced these filters on schedule.
Another consideration is to make sure you do not use a filter with a higher MERV rating than your HVAC can handle. While the MERV 11 or 12 filters may seem like great choices you need to be careful you do not stress the motor. In addition, a higher efficiency filter like this may contribute to lower indoor air quality if the air in your home is not circulating enough.
Best for: General air quality for a large sq ft area in your home. Silent but does not address moderate to severe allergies, asthma, fine dust, smoke or odors.
What it Filters: Not rated to filter any of the smallest particles that trigger asthma or allergies. Typically rated for 80% or more of the larger sized dust particles.
A whole house air cleaner works by leveraging the air ducts and the fan from your HVAC’s air handler. Like a giant fan that is built into your home. In a sense you are adding an air filter to this big networked system.
The advantages are that this system is quiet and there is no separate air cleaner in your rooms.
The disadvantages are that it requires a professional installation. Another issue is that filters like this that tie into your air conditioning system have the same issue as the lower priced store bought filters. That is, your air handler is not designed to be run with a high efficiency filter since this filter adds a lot of air flow resistance.
This means these systems use lower grade filters that are less than true HEPA filters. A whole house HEPA filter is generally not a genuine true HEPA filter but rather a HEPA-type filter. So, they are not rated to remove the smallest, most important airborne particles. Specifically, airborne particles smaller than 1 micron.
One workaround is to buy a whole house air cleaner that also includes it’s own fan. This enables the central air purifier to have higher air flow so it can use a better filters. So, you have the big fan (air handler) for the HVAC duct system and a smaller fan for your central air purifier that is tied into the ducting.
In the research we have done we do not see any of these systems use a true HEPA filter so the filtration ability for the smaller particles.
If you have mild allergies or are looking for general household air cleaning for a large square footage area, this could be a good solution.
A challenge with this type of central air purifier is that you are only getting clean air when your HVAC system is running. Since, your air conditioner and heating system accounts for half or more of most people’s energy bills it could get expensive to operate this system.
Furthermore, if you are more sensitive to allergies, have asthma or need to remove tobacco smoke particles you will not find a whole house air cleaner with the higher filter efficiencies. It’s too hard to get air through an activated carbon filter in order to clean indoor air pollution such as tobacco smoke odors, cooking odors, etc. As a side note, if you need to remove radon gas, carbon seems to be only somewhat effective. It seems getting proper ventilation in your basement may be your best option to remove radon gases from your home.
Best for: allergens, fine dust, mold spores, asthma, cigarette smoke, and odors.
What it Filters: 90%+ of the smallest particles that trigger as asthma or allergies and 100% of the larger sized dust particles.
Room air cleaners with a genuine true HEPA filter work the best in removing the smallest particles for a room. Since it has a dedicated fan it is able to use a higher efficiency filter.
There is no installation with a room air cleaner. The products we have tested so far are ready to use out of the box.
To compare this to the filter options described above a true HEPA filtration system at MERV 17 will remove 99.97% or more of the particles less than 1 micron in size (down to 0.3 microns). As well as 99.97% or more of the larger airborne particles. If you go with a HEPA filtration system with MERV 18 filters you get more than 99.99% filter efficiency across all of these particle sizes.
A challenge with this type of air filtration system, in most cases, is that it will not clean your whole home unless you live in a small apartment or tiny home. They are meant to clean one room.
Since we began to test units, I have started to use room air purifiers. I place one in my bedroom and one in the living room since that is where I spend most of my time at home. While they are quiet to where I am used to the white noise, they are not silent like the installed whole house systems.
Another advantage to a room air cleaner is that if you are looking for smoke removal you can find units with sufficient carbon to get rid of the smell for fresh air. Or possibly use to remove other odors. It gives you more options to find a model that addresses your specific need.
Some air cleaners use UV-C germicidal lamps. The UV lamp acts as an air sterilizer to help with particles such as mold spores from growing.
Also, there are some UV lights that are used in the air ducts of an HVAC system. An example is the Fresh-aire UV system. If you have issues with standing water in your ducting this is something to consider. This is often used to prevent mold growth and black mold or sick building syndrome in office buildings. We hare not aware of this in residential use.
Here is a listing of some of the more popular whole-house air cleaner brands and products.
In this article we gave an overview for whole house air purifiers. One option is the low cost furnace filter in your return air duct of your HVAC or air conditioning system.
From our testing and research it really comes down to choosing between a whole house vs a room air purifier.
For general cleaning and quiet operation without needing an air purifier in your room, a whole home air purifier may be a good option.
If you do not want to deal with an installation or are looking for better dust, allergen, pet dander, mold, or the removal of indoor air pollution like smoke or odors then a high performance room air purifier is your best choice. The reason is you get higher efficiency filters and a dedicated motor to clean the air more frequently. You also have more and better choices for odor or smoke removal.