The air filter in your home’s furnace, air conditioner or heat pump is a crucial component of the whole system. They may not look elaborate as they’re mostly cardboard and fiber, but air filters greatly affect the performance of your unit. Not only in regards to your indoor comfort, but they also have a major impact on the HVAC equipment itself. Here is a little more information on air filters, how they work, and why they are so important to maintaining your home’s heating and cooling systems. Hopefully, it will also aid you in selecting the right filter to best fit your particular needs!
How Air Filters Function and Work
Air filters are usually manufactured with one of the two following materials: spun fiberglass material or pleated paper/cloth. The material is then enclosed in a cardboard frame, then sized to fit all of the various HVAC systems that exist. The filter’s primary function is to trap and hold all the different kids of particulates and contaminants in the air that circulates through your heating and cooling system – most of which can directly affect your health and comfort. Some of these contaminants include:
- Mold & spores
- Hair & Animal fur
- Dust and dirt
- Fibers and lint
- Metal, plaster or wood particles
The air filtration usually occurs when the disbursed air is “sucked” back into the HVAC system to be conditioned and then used again. During this process, the air is forced through the air filter and the spun fiberglass or pleated paper/cloth traps the particulates and contaminants from the air and removes them, thus not allowing the particles to be recirculated into the air you breathe.
Filter Efficiency and MERV Ratings
As with almost all of the products that we purchase, there are lower-end, mid-level and high-end choices available. Not all products are created equal and not all air filters will clean your air with the same efficiency. The higher the quality, the more contaminants that will be removed from your indoor air. Keep in mind that these higher quality air filters are usually a bit more expensive.
This is where the MERV rating comes into play. MERV stands for “Minimum Efficiency Reporting Value” and is a numeric value for rating and comparing the filter’s efficiency and performance. The range for Standard MERV values is typically from 1 to 16, with the number indicating how well the filter will remove material from the air. The higher the MERV number, the better the filtration.
MERV 1-4: Common standard filters. Basic filtration. Low cost.
MERV 6-8: Good filtration usually used in residential settings. Made of pleated paper or cloth.
MERV 9-12: Relatively high efficiency, middle of the road filters. Can trap particles of 1 micron or larger.
MERV 13-16: Highest efficiency, best standard filters available. Can trap particles as tiny as 0.3 microns or larger.
There are filters available with MERV ratings higher than 16, however they are thick and dense and your typical residential HVAC system cannot readily handle them. In fact they can actually interfere with the airflow by restricting it. This in turn could actually reduce the effectiveness of your heating and cooling systems and can even result in damage to the HVAC equipment. You must make sure that your HVAC system can handle filters with MERV ratings higher than 16 before buying and installing one.
There are also additional units that can be installed along with your HVAC system that are designed for air filtration and purification. These air cleaners can provide an additional step “on top” of the regular filtering, thus cleaning your air even further.
Maintaining Your Air Filter
All of the air that circulates through your HVAC system, to either heat or cool your home, will eventually pass through the air filter. This is why it is so VERY important to keep your air filters clean and change them regularly. Dirty, clogged air filters can:
- Cause HVAC system malfunctions and equipment damage.
- Reduce airflow inside the HVAC system, making the fans work harder and wear out quicker.
- NOT remove particulates and contaminants as effectively as they should, therefore releasing these back into your indoor air (or the air that you and your family breath).
- Cause contaminates to built up in your duct work.
- Cause the HVAC equipment to work harder, increasing your home’s energy usage and your monthly electric bill payments.
Air filters should be checked at least once a month. If they are dirty they should be changed with a fresh clean air filter. When removing the air filter from the handler, if you hold it up to a light source you will be able to see if the filter is dirty or clogged – if you can’t see the light through the filter, then it’s definitely time for it to be changed.
US Home Filter’s is Here for YOU
Determining the size that your system requires and choosing the MERV rating that is best for you can be a little overwhelming, especially if you have never purchased air filters for your home or if you have a new unit or home to buy filters for. You can take a look at our air filter measurement guide to help you pick the right size or call us and we can easily assist you with ordering the exact air filter size you need and recommend the best rating for you depending on the level of filtration you want. Whether you need AC or furnace filters, a specialty Whole House filter, a Grille filter, or even a custom air filter size, we have a professional and helpful staff ready to take care of you!