Spring means many things: longer days, blossoming flowers — and for many people, itchy eyes and runny noses.
By the time March rolls around, allergy season starts picking up. From then through the summer, pollen, dust mites, pet dander and sometimes even mold team up to torture allergy sufferers.
Fortunately, there are plenty of ways to reduce allergens in your home. And, your air conditioner can play a big role in that. One way is indirect: An important step toward keeping out allergens is keeping your windows closed. That makes your air conditioner just about essential for home comfort.
However, your a/c can also play a more active role. That’s true for a window unit, central system or ductless HVAC. An air conditioning system can act as a filter for a single room or your whole house.
To do that, however, you’ll need the right kind of air filter. Any air filter will prevent dust and large debris from getting into your system. However, allergens are much smaller than those objects. Therefore, you’ll need a special filter to catch them.
But, not all those filters are created the same. You’ll need to know the lingo and decide what you need, exactly. Then, you can choose the right air filters for your home.
Here’s a quick primer on choosing the right air conditioner filter to help with your allergies:
The term “HEPA” doesn’t have to do with a brand or even style of filter. Instead, it’s a rating that tells you how well a filter can prevent very small particles from passing through it. HEPA stands for “High-Efficiency Particulate Arrestance.”
HEPA designations are given by the U.S. Department of Energy. In order to be considered a HEPA filter, the filter must block 99.7 percent of all particles that are .3 microns thick or larger.
Here’s a way to understand how small that is: The thickness of a piece of paper is no more than 180 microns. Even smaller is a dust mite at 100 microns. Pollen particles are anywhere from one to 100 microns, and bacteria particles range from .3 to 60 microns.
Related: How often should I change my air conditioner filters?
Therefore, a HEPA filter on your air conditioner goes a long way from blocking allergens. A variety of manufacturers sell filters with HEPA ratings. A HEPA filter is very powerful, but it’s not always the best option for a central air conditioning unit. We’ll get into why a little later.
Instead, a HEPA filter is more common on an air purifier in the home. These are individual units that treat the air for allergens. They don’t cool or warm the air like an HVAC system. But, you can still use them along with your a/c. This is helpful if you really need that level of filtration or want to especially treat certain rooms.
A MERV filter, like a HEPA filter, has a name that refers to a rating. MERV stands for “Minimum Efficiency Reporting Value.” This is a measure of the particle sizes it lets pass through it.
The difference between the MERV and HEPA rating is that MERV measures for larger particles. HEPA, as we mentioned, must block all particles .3 microns or smaller. A MERV-rated filter will remove particles between .3 and 10 microns.
Filters can have a MERV rating from one through 16. Higher ratings mean fewer particles can pass through it. Of course, a filter with a lower MERV rating can’t block the small particles a HEPA filter can. But, something this is a good thing.
In order to block such small particles, the pores on a filter must be very small. This requires more pressure to push air through with the same strength as before. The smaller the pores, the more pressure is needed.
As a result, a HEPA filter or filter with a high MERV rating causes an HVAC system to be less energy efficient. And, in some cases, you’ll get a drop in air quality. This occurs when the system just can’t push enough air to cool the area properly.
In these cases, a MERV-rated filter is the way to go. And, most of the time they’ll work well enough. Filters with a MERV rating from seven to 12 are often good enough for homes. Ratings from 13 to 16 are usually found in hospitals.
Carbon Fiber Filters
Carbon fiber filters work much differently than filters with HEPA or MERV ratings. Those rely on smaller and smaller pores to prevent particles from passing through. Carbon fiber filters, on the other hand, use a chemical process called “adsorption.”
This is when molecules stick to the surface of an object that they come into contact with. They form a thin layer around that object. In this case, that object is a carbon fiber.
It’s kind of like water tension, where the molecules in water can stick together enough so that the liquid can stay together a few millimeters above the rim of a cup.
Here, each tiny piece of carbon is very porous, like a sponge. They attract tiny molecules like pet dander, bacteria and other allergens. As particles pass by, they bond to the carbon pieces. This means the air that continues through the system is now free of those allergens.
Carbon fiber filters are also good for filtering out other contaminants such as cigarette smoke. They also get rid of odors from smoke and other pollutants.
The good news about carbon filters is that they don’t affect airflow nearly as much as some other filters. However, they’re often not as powerful, either. The strongest ones only go as high as a MERV 8 rating. That puts it on the lower side for filters that take care of allergens.
So, a carbon fiber filter may do the trick if your allergies aren’t too bad. You can use one without worrying about losing air pressure in your HVAC system. There’s also the odor removing features that not all MERV filters can do. And, in some cases, you can combine a carbon filter with another filter that has a higher MERV rating.
Are you still suffering from allergy symptoms even when your air conditioner is working? Contact us to find out how we can help improve your air quality.