What is MERV?

Air filter efficiency is measured by the Minimum Efficiency Reporting Value (MERV). The higher the MERV the more particles, and smaller particles, it will filter from the air. A filter with a MERV number indicates that it has been tested at an independent laboratory according to ASHRAE test methods.

What MERV should I use for my needs?

At BuyFilters.com, we’ve designed our filters to protect you and your family while enabling your air comfort system to work at its most efficient. We've put a filter selection guide together that should help you choose a filter based on your goals, rather than just choosing based on what particles might be captured. Remember, the higher the MERV, the better the protection. Higher MERV filters accomplish all the benefits of lower MERV filters in addition to their targeted protection area of your breathing zones (see chart below). If you need advice on which filter to choose, feel free to email us or online chat.

MERV Effect on Breathing Chart

What is ASHRAE?

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (www.ASHRAE.org) developed the MERV measurement method as a way to standardize the industry and give consumers a consistent way to measure the efficiency of air filters. 

How do I measure my filter?

Simply measure your old filter for its outer-most height, width and thickness. In nearly all cases your filter’s measurements may be found imprinted on your old filter. Most filters print the nominal size, which is usually larger than the actual size. For instance, a 20x20 filter might actually be 19.5” x 19.5”. If you need a hard to find size or even a custom size let us know. BuyFilters.com will accommodate your needs!

How to measure a filter

Why pleated filters vs. flat fiberglass?

Fiberglass filters offer little protection from dust and harmful particles, trapping only the largest particles. Over time, the dust that passes through a fiberglass filter can build up in your furnace, air conditioning system and air ducts. This build up reduces efficiency and provides a potential site for mold growth. BuyFilters.com offers only pleated filters because they provide the best combination of air cleaning and energy efficiency. MERV 8 and above pleated filters protect heating and cooling equipment from dust buildup, allowing it to operate at optimal energy efficiency. They also reduce dust in your home and trap particles that irritate nasal passages and breathing airways. By pleating, we squeeze in much more filter media. In fact, a 20x20x1 pleated filter can have up to 16 square feet of media. A 20x20x1 fiberglass filter has less than 3 square feet of media surface area. More filter media means more dust holding and less restriction to airflow. Buyfilters.com filters have more filter media than competing products, giving you optimal value and performance.

How often should I change my filter?

How often should I change my filter?
The size and thickness of your filter will determine its effective life. Please refer to the recommended replacement schedule for your specific filter(s). A dirty filter restricts air flow and makes your air system work harder, increasing energy bills and reducing the life of your expensive equipment. Replacing your air filter frequently should more than offset the cost of the filter in energy savings alone. According to the U. S. Department of Energy, “Heating and cooling account for about 56% of the energy use in a typical U.S. home, making it the largest energy expense for most homes. Clean or replace filters on furnaces once a month or as needed. (www.energy.gov/public-services/homes/heating-cooling)  

Will you remind me to change my filter?

Yes! When you place your order just let us know that you would like to receive a reminder email and we’ll let you know when it’s time to change your filter or order your next supply! Remember, clean filters save energy and clean your air better.

What about returns, refunds and other policies?

Please see our Store Policies (click link) for information on returns, refunds, shipping and cancellations or, for privacy information, visit our Privacy Policy Page.

Helpful Links
American Lung Association ||| National Air Filtration Association ||| American Society of Heating, Refrigerating and Air-Conditioning Engineers