Is an electrostatic air filter better than a disposable filter? If you need new filters for your furnace you've probably noticed that there are a lot of options. Many homeowners prefer using electrostatic filters, but are they the best choice for you?
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The truth is, there isn't an easy answer to the question. It really depends on your situation. In this article we'll help you determine if an electrostatic air filter is a good fit for your home, and if it isn't, we'll give you the facts you need to know to purchase a different type of filter.
Furnace Air Filters: What They Do
The minute you turn on your furnace, air from inside your house is pulled into the unit. As the incoming air flows thru the air filters, small particles of dust and other airborne contaminates are removed. Then the air is heated or cooled before it's returned back into your home.
The primary role of the air filter is to protect the blower fan and other system components from airborne particles that are pulled in thru the return duct. As the furnace filters the incoming air, it's also improving the quality of the air it returns to your house and thus prevents contaminants from being recirculated.
It's a common misconception that an air filter's role is to clean the air you breathe within the home. Although, there is truth to this statement, an air filter's primary purpose is to protect the furnace.
How Furnace Filters are Rated
Furnace air filters use a rating system called MERV (Minimum Efficiency Reporting Value) which rates the overall effectiveness of a filter on a scale of 1 to 20. Check out the MERV rating chart HERE.
The higher the rating, the more efficient the filter is at trapping dust particles and other airborne contaminants. A MERV rating between 8 to 11 is typically adequate for most homes.
A filter with a MERV rating of 8 would be considered an everyday filter. It's designed to filter out pet dander, pollen, hair, lint, dust and dust mites. Advanced filtration begins with filters rated at 11. These filters remove everything an 8 filter does and in addition removes mold, smog and smoke. Premium allergen control starts at a 13 MERV rating, which can remove viruses, allergens and bacteria.
You should always check your furnace manufacturer's literature for the maximum MERV rating recommendation. The higher a filter is rated the less air is allowed to flow thru, causing your furnace to work harder.
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Electrostatic Air Filters
Electrostatic filters take advantage of static electricity. As the air enters the filter, it's given a positive charge, and as the positively charged air travels thru the next few layers of the filter, the charge is released and traps the particles within the filter.
Most electrostatic air filters can successfully remove large particles, dust, pollen, and carpet fibers. However, they tend to do a poor job of capturing small particles and mold spores.
One of the disadvantages with electrostatic filters is they must be cleaned on a regular basis, typically every 4 weeks. When the filter's surfaces are covered in dust, the contaminates entering the filter have no where to go since they will not "stick" to a dust coated surface. The positively charged air, having no where to release, will drop it's particles on other surfaces after leaving the filter.
A dirty filter will do a poor job until it's replaced or cleaned. This cleaner, that can be purchased thru Amazon, is made specifically for cleaning electrostatic filters.
This video shows how to clean an electrostatic filter.
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Trophy Air Electrostatic Air Filter
The Trophy Air Electrostatic Air Filter is designed to improve your home's ventilation efficiency. It has four layers of high-grade aluminum and two layers of electrostatic media.
Disposable Air Filters
Disposable filters come in a several different styles, such as fiberglass, pleated and disposable electrostatic. Let's take a look at each:
The original purpose of a fiberglass filter was to keep debris from entering your furnace, these filters were never intended to improve the quality of your indoor air.
Disposable fiberglass filters are composed of 1-inch thick spun fiberglass within a cardboard frame. They are extremely cost effective and can be purchased for just a few dollars each.
Fiberglass filters should be replaced every several months and they're capable of filtering out large particles such as lint, dirt and dust. In most cases they have a MERV rating between 1 and 4.
If you, or a family member, struggle with allergies or breathing disorders these filters are not a good choice.
E-Z Flow Heavy Duty Air Filter
These fiberglass filters are manufactured by Flanders and are available in multiple sizes to fit nearly every unit. They are rated MERV 4.
Disposable pleated filters are made from either polyester or a cotton paper blend, with a rigid cardboard frame. These filters typically cost around $10 each.
Pleated filters are capable of trapping smaller particles as well as mold spores. Many furnace manufacturers do not recommend using pleated filters because they reduce the air flow to the unit. Always check your furnace documentation before using.
Filter Buy Pleated Air Filters
Filter Buy makes these pleated filters with a MERV 11 rating. They'll capture 95% of airborne particles including pet dander, smoke, pollen and mold spores.
A disposable electrostatic filter functions in the same manner as a permanent filter. They will, however, need to be thrown away rather than reused.
3M Filtrete Electrostatic Air Filters
3M's Filtrete Electrostatic Filters are an excellent choice. These disposable filters should be changed every 3-months and work well with high-velocity heating and cooling systems.
High-Efficiency Pleated Filters
A high-efficiency filter is made of up to 5-inches of pleated synthetic cotton. These filters are capable of filtering out very small particles, and are rated quite high on the MERV scale.
Honeywell Ultra-Efficiency Air Filters
High-efficiency filters are an excellent choice for individuals who suffer from respiratory issues or autoimmune disorders. Check your owners manual before using these filters as they are not recommended for every furnace.
This video shows how to change your furnace air filter.
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Electrostatic Filters vs. Disposable Filters
Electrostatic filters have a lot of strong points that make them a great choice for your furnace, but how do they compare against disposable filters? Let's take a look.
Electrostatic vs. Fiberglass Filters
Electrostatic filters are the clear winner here. Although fiberglass filters are very inexpensive, they are only able to remove large particles from the air. They also offer little to no effect on improving air quality.
Electrostatic vs. Pleated Filters
Pleated filters need to be changed every 3 months, where electrostatic filters should be cleaned monthly. There's quite a wide range of pricing with pleated filters, and high quality ones can be quite expensive.
Air flow is restricted to your furnace with pleated filters and not all manufacturers recommend their use, so always check your owners manual before switching. But ultimately, whether you decide to use a pleated filter or electrostatic may simply come down to personal preference.
Electrostatic vs. Electrostatic Filters
You may think that permanent electrostatic filters are the same as the disposable version. But there are a few differences. The main difference, of course is that the disposable filters can not be reused, and replacing them each time you change your filter can become expensive.
Disposable electrostatic filters typically have a higher MERV rating making them a good choice for individuals with children, pets, and smokers.
Electrostatic Filters vs. High-Efficiency Pleated Filters
If your furnace is capable of using a high-efficiency pleated filter, these are an excellent choice. Although, they are an expensive filter.
With a MERV rating between 13 to 15, they are capable of catching very small particles and can prevent air-borne illnesses. An excellent choice for individuals who have respiratory issues or auto-immune disease.
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