If you want your furnace to serve your home effectively, its filter is critical to continued operation. However, with all the filter varieties on the market, which one is best? Regardless of any hype you encounter, none of them last forever without ever needing to be changed. Here’s what you need to know before purchasing your next filter.
The very first thing to consider is the filter size. There are three dimensions to air filters: length, width and depth. Your system’s specifications determine what is needed for all three dimensions.
Generally, the deeper your filter, the longer it will last. However, you want to be careful not to use a bigger filter than your system is designed to handle. Air filter depths range from 1 to 6 inches. Using the wrong size may cause the filter to become ineffective, allowing contaminants to flow into the internal components of the system, reducing its efficiency.
Air filters are rated on the MERV scale, or minimum efficiency reporting value. This rating indicates the size of particles a filter will capture from the air. Up to MERV 6 will filter out lint, pollen, dust, dust mites and mold. MERV 8 will remove pet dander, smoke, smog and allergens. MERV 12 will also catch bacteria and viruses.
Be careful to watch your system for indications you’ve installed a filter that’s too dense for your equipment to function properly. These include reduced air coming from your vents, cold or hot spots around your home and insufficiently heated air.
Disposable or Washable?
The most common filters are the disposable kind you can purchase at your local hardware store. However, you can also find washable filters, which are attractive because you don’t have to continue purchasing new ones. Is there a difference between the two, and which should you use?
Washable filters are a good option if you aren’t concerned about filtering small particles. Washable options generally have a rating of about MERV 8. If you’re looking for finer filtering, you’ll want to look at disposable filter options. Within the disposable options, you have the choice of pleated or flat-panel filters.
Pleated or Flat-Panel?
Are pleated or flat-panel filters better for your furnace? Flat-panel filters are typically made from fiberglass, and they usually have a rating of MERV 2 or MERV 3.
Pleated filters, on the other hand, are made from pleated polyester, cotton or paper. Even within these options, you have lower-end products that typically run around $5 per filter and have a rating of about MERV 6. Higher-end pleated filters have a rating of up to MERV 16, but these can run as much as $100 per filter.
In addition to filtering more particles from the air, pleated filters are less likely to clog quickly. Flat-panel filters may clog in as few as 30 days, whereas 1- and 2-inch pleated filters may last around 90 days, depending on your air quality.
What About HEPA?
If you’ve paid attention to any air quality conversations, you’ve likely heard about HEPA filters. These often rate between MERV 17 and MERV 20. They’re tempting because of how much they will remove from the air.
The challenge with HEPA filters in most residential systems is that the furnace generally won’t create enough draw to pull the right volume of air through the filter to effectively serve the system. However, there are a lot of portable air purifiers that use HEPA filtration, and one of these can be a great addition to your home.
Choosing the Best Filter
To determine which filter you need, start by finding the size filter your system requires. You can see the size of most disposable filters on the cardboard frame around them. If you don’t see a size printed on the filter, you can always measure it for yourself. The information is usually available in your unit’s owner’s manual as well.
Once you know the filter size, consider how much filtering power you require. This will help you determine whether you need a flat-panel, pleated or washable filter.
Stay clear of any filter that claims to be permanent. Every filter will need either cleaning or changing to keep air flowing through it effectively. If you decide to use a disposable filter, consider checking it monthly and gently vacuuming the dust off the intake side to keep the filter functioning more efficiently between changes.
Bernard Heating & Cooling proudly serves the Akron and Hudson communities in this part of Ohio with exceptional heating and air conditioning installation, maintenance and repair. Call us today to schedule an appointment with one of our friendly and knowledgeable HVAC technicians.