How to Find the Right Furnace Filter

As a responsible homeowner, you know you have to change your furnace filter regularly. After all, your filter protects your blower fan and compressor from particles and debris that would otherwise damage your unit.

But when you go to the local department store, you can’t help but feel a little overwhelmed by the options. The countless sizes, styles, and designs make you wonder if you can possibly choose the right one for your home, and you worry that if you choose the wrong one that you’ll damage your heating and cooling system.

Fortunately, you can select the right filter for your unit if you follow these simple steps.

1. Understand MERV Ratings

Minimum Efficiency Reporting Value, or MERV, is the rating scale for furnace and air conditioning filters. The American Society of Heating, Refrigerating and Air-Conditioning Engineers assign filters a number based on the product’s ability to remove particles from the air. A filter with a MERV rating between 1 and 4 offers minimal filtration while a rating between 17 and 20 offers maximum filtration worthy of clean rooms and hospital care.

Of course, a high MERV rating doesn’t necessarily mean you’ve chosen the best filter for your home. Filters with higher ratings have smaller filter pores. Some systems can’t pull in enough air through microscopic pores to work effectively, so you need to explore options based on your needs.

2. Explore Available Filter Options

If you or a loved one has allergies, asthma, or a medical condition, you’ll want to consider a filter that effectively traps contaminants and small particles. In contrast, if you have no medical concerns and don’t plan on living in your current home or apartment for long, you might not want to invest much in a filter.

To help you decide what to choose, take a quick look at the following filters:

  • Disposable Fiberglass. Created with 1-inch fiberglass, this filter prevents larger particles such as lint or dust from clogging your system. It often has a MERV rating between 2 and 3.
  • Disposable Pleated. Containing polyester or cotton paper, this filter removes particles such as spores and mites. It has a MERV rating between 5 and 7.
  • Disposable Electrostatic. This filter features self-charging electrostatic cotton or paper that attracts small particles. Its MERV rating ranges between 8 and 9.
  • Permanent Electrostatic. This filter also features self-charging cotton fibers that attract small particles. Homeowners can remove and wash the filter to extend lifespan. Its MERV rating stays between 8 and 9.
  • High-efficiency Pleated. Made from 4-inch pleated cotton, this filter attaches to a heavy metal grid. It removes the smallest particles, and it has a MERV rating between 14 and 16.
  • Washable or Reusable. This filter features several layers of polypropylene weave or wire mesh that blocks some larger particles. Due to its durable mesh material, homeowners can remove and wash the filter, and it costs less than permanent electrostatic. However, it costs more than disposable filters and only has a MERV rating between 1 and 4.

Keep in mind that you want to strike a balance between effective filtration and cost.

3. Work With Your Budget

As you shop for filters, remember that even high-quality filters will need either regular replacement or regular cleaning (depending on which you choose). Unless you have a lot of extra funds, you might not be able to afford to buy the best and most expensive filters again and again.

If necessary, do a little more research into your preferred furnace filters so you can decide whether you want to sacrifice value to save money or invest more money to ensure quality filtration.

Ask Your HVAC Technician for Advice

The above guide can help you determine a good choice for your furnace. However, your furnace may have additional requirements that further limit your buying options.

If you don’t know what kind of furnace filter your unit needs, talk to your local HVAC technician. He or she can recommend several options within your price range as well as give you additional advice on how often to replace your filter.