Choosing the Right Air Filter | Filtration Options & Types
As with most everything, there are a lot of options when it comes to choosing and purchasing furnace filters. Although most people simply look at their existing filter and replace it with the same, it’s a much better idea to look at your filtration options and choose the best one for your system’s health and home’s indoor air quality.
First, you need to understand MERV (Minimum Efficiency Reporting Values):
MERV is the basic rating system for HVAC filters, ranging from 1 to 20. In general, the higher the MERV rating, the better the filtration. This, however, does not necessarily mean a better filter for your home. In fact, the MERV rating is meant to measure the effectiveness of the filter at removing particulates in the air .3 to 10 microns in size. The tighter the air filter, the more pollen, dust, and dander it is able to capture, but sometimes this means sacrificing airflow to your system.
A filter that captures a lot of airborne contaminants, but strains your system by not giving it the airflow it needs, could end up damaging your system and contributing to poor indoor air quality. This is why it is important to do your research and consult with a HVAC professional before deciding which air filter is right for you. In general, an air filter with a MERV rating of 7-12 is good enough for most homes, while MERV ratings of 14-20 tend to be reserved for medical facilities.
The quality of your air filtration also heavily depends on how frequently you replace or clean your air filter. Make sure to follow the manufacturer’s instructions.
5 Air Filtration Options
Most filters fall into two main categories: disposable and washable. Disposable filters simply get tossed in the trash after 30-90 days (wait no longer than 90 days to replace your disposable air filter, unless the manufacturer’s instructions say otherwise).
Watch this video to learn how to replace your HVAC filter:
Washable filters can be reused. All you have to do is take the filter outside and wash it down with a hose until the water going through the filter come out clean on the other side.
Watch this video to learn how to clean your washable air filter:
Okay, so now that we know that your air filter will fall into one of these two categories, we can get more specific:
1. Fiberglass (disposable)
These are the most popular filters on the market, but not necessarily the best. They are most popular because you can find them for as cheap as $1. Lots of renters use these filters, but they do practically nothing to filter your air from small airborne contaminants. They help prevent large particles, like dust, lint, and debris from gunking up your system, but have little to no effect on air cleaning and purifying. MERV rating: 1-3
2. Pleated Polyester (disposable)
In contrast to the flat fiberglass filters, these pleated filters do a better job at filtering out smaller particles, such as mites and pores. They cost about $5, but require more frequent filter changes. Since these filters are pleated, there is a larger surface area for capturing airborne contaminants, however, this added surface area will also increase resistance to airflow, causing your HVAC system to work harder. You can also find washable polyester filters, which tend to cost a little bit more upfront, but will save you a considerable deal of money in the long run. The cost is usually a lower MERV rating. MERV rating: 5-13
3. Electrostatic (disposable)
Electrostatic air filters use static electricity to capture more contaminants than either fiberglass or pleated polyester filters. The paper or cotton fibers are self-charging and are able to capture small particles, but will cost you more, about $10. MERV rating: 10
4. Electrostatic (permanent)
These electrostatic filters are similar to the disposable ones, but are slightly less effective. Since they easily washable and last for 6-8 years, however, they end up costing a lot less. One filter will cost around $15-$20. That is, unless you need a custom size – those cost more. MERV rating: 8
5. HEPA (disposable & permanent)
The granddaddy of all air filters, high efficiency particulate arrestance (HEPA) filters offer the best in air filtration, which is why they are used in medical facilities. They are normally pleated and very thick (4-5”), with MERV ratings ranging from 14-20. These high-efficiency filters are recommended in households that have respiratory and autoimmune problems. Unfortunately, they often require special modification of your existing system to allow for the larger-sized filter. They are more expensive, around $100, but only have to be changed once per year (check every 6 months). MERV rating: 14-20
It’s important to keep air filtration in mind when you are installing or replacing your existing HVAC system. Filter come in preset sizes, so your system should be designed with a specific filter in mind. Ordering custom filters get expensive, so talk with your HVAC professional about which system and filtration system is best for you.
If you really want clean air, ask Pacific Air Systems about the revolutionary technology developed by NASA in Air Scrubber Plus.
For more tips on selecting a new HVAC and filtration system, read our other blog articles:
- What Homeowners Need to Know Before Buying a New Furnace
- Allergies? Flu? Give the Gift of Clean Air with Air Scrubber Plus
- HVAC FAQs | Maintenance, Repair, and Replacement
For more advice on heating and cooling systems, indoor air quality, and air filtration systems, call Pacific Air Systems Heating & Cooling at (253) 292-3995 for a professional indoor air quality consultation!
Since 1984, we’ve proudly served homeowners throughout Federal Way, Graham, Spanaway, University Place, Steilacoom, Sumner, Lakewood, Puyallup, Tacoma and Gig Harbor.