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Disposable Furnace Filters Vs. Washable Filters

One of the best and easiest ways to care for your HVAC system is to change your furnace air filter on a regular basis. The primary function of HVAC filter is to prevent airborne particles from entering the furnace. When this occurs, the furnace works less efficiently, which can impact the air quality in your home.

The most common type of air filter is a disposable filter. These air filters operate just as their name suggests: after a few months – or according to the manufacturer’s guidelines – you throw the old air filter in the trash and replace it with a new one. One type of furnace air filter some people may not be familiar with is an electrostatic filter, otherwise known as a washable furnace filter. Some even call washable air filters “permanent” filters.

There’s a debate about which type of furnace filter is better for your HVAC system. We believe disposable furnace filters are the best option. Let’s talk a little about the differences between these two types of furnace filters and why we recommend using disposable air filters.

What is a Washable Furnace Filter?

Most washable filters have an aluminum frame that holds the woven electrostatic fibers that are static prone so they will attract and trap airborne particles. When the filter has accumulated dust and dirt after a few months, it is removed and hosed down to rinse away all of the debris.

Because there are several layers of fibers in washable air filters, they should be washed thoroughly. To prevent mold and mildew from forming, the filter should be dried out completely before it is replaced. This is why some people who use washable filters keep a second filter on hand to insert immediately while the other is being cleaned and dried.

Benefits of Disposable Furnace Filters

High-efficiency disposable filters are great at trapping small particles and have a Minimum Efficiency Reporting Value (MERV rating) as high as 9 to 12 MERV. This is the measure of the effectiveness of furnace air filters. High-efficiency disposable filters can trap as much as 95 percent of the larger particles around your home.

There are many professional opinions about the effectiveness of washable furnace filters. Some think they are a great idea and a useful way to save money. Others are less enthusiastic, stating that electrostatic filtration may not remove larger dirt and dust particles as effectively as the disposable filters can. Some HVAC companies are completely negative about washable filters, believing that they are the worst type of filter you can choose.

With an average MERV value below 8, reusable filters often remove fewer particles than many of the disposable filters, which might overtax your furnace or air conditioner. If you own furry pets, you might find that the electrostatic filter may not remove as much pet dander as you might like. And, if the filter is not completely cleaned or dried before it’s replaced, it can build up a layer of dust, mold and mildew that causes a spread of bacteria that can get blown around your house and create an unpleasant odor.


Disposable filters are more effective at trapping smaller particles. Washable are only good at protecting from large particles like dust. They do not filter out pet dander, bacteria, viruses or smoke, especially when they aren’t changed often enough.

The general feeling here at Star Heating and Cooling is that there are more negatives regarding the use of washable furnace filters than there are benefits. Our recommendation to our customers is to use the disposable, pleated filters so you can choose the amount of filtration (the MERV value) that is right for your needs. You might be disciplined enough to remember to clean and dry the filter every month or so, but here at Star, we much prefer to just simply discard all of the dust, pollen, and other particles when the disposable HVAC filter gets dirty.

Contact Star for All of Your HVAC Needs

Whichever furnace filter you decide to use, it’s one of the most important maintenance tasks that can be performed on your system. At Star Heating & Cooling, we have a trusted team of highly skilled, NATE-certified technicians to help you with all of your heating and cooling needs. Contact Star today to schedule maintenance on your HVAC system.