Choosing the Right Furnace Filter

Furnace filters are often one of the most overlooked pieces of home maintenance; they’re not at all exciting like power tools, and far from eye-catching like crown molding. But that does not mean they are unworthy of your attention. The right furnace filter can save you money and improve your indoor air quality. Originally, these filters were designed to protect all the moving parts of your furnace, but now furnace filters prevent harmful particles from being recycled back into your home’s air supply. Furnace filters are rated on a scale of 1-20. This scale is called the Minimum Efficiency Reporting Values scale, or MERV.

Disposable Fiberglass

This is probably the option you think of when we say “furnace filter.” Made from 1”-thick spun fiberglass, this filter often does little more than prevent large-sized particles from clogging your system. With MERV ratings around 2-3 and a cost of just a couple of bucks, these filters are great for those on a budget and no health concerns. The sad part is, they really don’t do much to clean the air, so they are not worth the savings if you need cleaner air in your home.

Disposable Pleated

This is another popular option. Made from polyester or cotton paper, this filter can remove some smaller particles like mold spores and mites, but they need to be changed frequently to avoid clogging and maintain efficiency. With an MERV rating of around 6 and an inexpensive cost in the $5 range, this option is great for people with a budget to keep to who need more cleaning power than a disposable fiberglass filter can provide. Additionally, if you are concerned about the environment and sustainably sourced materials, this option is often “green” by comparison to some other choices.

Disposable Electrostatic

This type of filter is made of self-charging electrostatic cotton or paper fibers. The static-cling aspect of this filter means it actively works to attract and trap small particles. With a mid-range MERV rating of 10 and an average cost of the same number, this filter type is great for homes with pets, children, or smokers. However, if replaced regularly over several years, these costs do add up.

Permanent Electrostatic

While similar to their disposable cousins, these options have a removable, machine-washable cotton filter that can be removed regularly and washed. With a reusable life of around 6-8 years, these filters are a great, cost-effective option. The MERV rating is slightly lower than the disposable kind, running around an 8, but the reduced cost over time is highly desirable ($15-20).

High-efficiency Pleated

This is the mac-daddy of furnace filters. Made from 4-5” deep pleated synthetic cotton, these filters are attached to a rigid metal grid to prevent leaks and fluttering. The MERV rating of these filters comes in at around a 14-16, and is well-worth the increased cost (around $100). Often used in hospitals, these filters are top-of-the-line, the best on the market. If you are interested in this filter type, it is important to realize that the bulky size of this filter means you need to plan special construction into your home to accommodate it, and that these should be replaced yearly. But in this case, you get what you pay for: a highly-effective, hospital-grade furnace filter that is ideal for people with severe respiratory or autoimmune troubles.

For more information on what types of furnace filters might be best for your home, contact Metro Express Services today! We have skilled professionals ready and willing to help you out!


Randy Murphy

Randy Murphy has been building his knowledge of the air conditioning and heating business for several years now. He first started applying his knowledge while working for his father’s HVAC company. Later, in 1987, Randy started his own business: Metro Express Service. He has been a top 10 Trane & Amana dealer for over eight years. When it comes to heating and cooling, Randy knows the business better than anyone.
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