Filter Info

Information about all of the different filter types from air filters, water filters, pool & spa filters and even car and motorcycle filters.

If it needs to be filtered, you can find a filter fast at Filters Outpost USA.

Filter Facts

Air Filter Replacement

How to Choose a Filter

When you are choosing an air filter, you will take into consideration size, MERV rating and brand. It is important to choose the right filter for your furnace and one with the correct rating - or ability to remove the particles found in indoor air. These particles are measured in microns, which are 1/1000 of a millimeter.

To give you a point of reference, a human hair is approximately 70 microns wide.

Furnace filters for homes generally range from a MERV (minimum efficiency reporting value) of 4 to 12.

MERV is the domestic and international rating system used in the industry, created by the American Society of Heating, Refrigerating and Air Conditioning Engineers.

In general, the higher the MERV, the higher the efficiency - and the price of the filter.

Low-efficiency filters many not filter dust as much as you would want, but will filter out enough larger particles.

Many furnace manufacturers suggest the MERV 2 traditional filters made of spun fiberglass because they allow maximum airflow, meaning the heat exchanger and blower motor on your furnace will be more energy efficient and have a longer life span before replacement or replacement parts are needed.

The next step up is a MERV 4 furnace filter, which is still very economical and allows good airflow. These filters will capture 80% of airborne particles that are 50 microns or larger. However, smaller particles in the 3-10 micron range will only be captured 75% of the time.

High efficiency filters (MERV 11 and up) may slow airflow so you will need to run the fan on your furnace more often, or even full time.

The benefit to a high efficiency filter is that it can capture as much as 99% of airborne particles. If you have allergy sufferers, low immunity, pet dander, smokers or just want things super clean, then a high efficiency filter is for you. It will get rid of pollen, bacteria and virus particles as small as 0.3 microns, as well as fumes and odors.

It will cost more and you will have to be diligent about changing the filter to protect your furnace, since it allows less air flow.

A good cross between filtration and cost is a MERV 7 or 8 furnace filter. These pleated filters generally capture 80%-95% of 5 micron or larger particles, which most homeowners find adequately efficient.

Changing your furnace filter regularly will protect your family's health, as well as your expensive furnace. A clogged filter will no longer trap particles and impurities efficiently, putting your family at risk.

A blocked filter can also cost you hundreds of dollars in wasted energy, or burn out your blower motor because there is not sufficient air flow and it overheats. Since a dirty filter restricts air flow into your furnace/air conditioner, it will have to work harder to heat or cool your home - which will result in higher energy bills.

If you are currently using a fiberglass filter in your furnace, do not switch to a high-efficiency one without talking to your HVAC technician. They can compensate for reduced air flow by boosting your fan speed.