4 Basic Types of Whole-House Filtration and Air Cleaners: Learn About Them
Whole-house filtration is most effective with a forced air HVAC system in the home. This design filters air continuously while the fan is running. Air filters for forced air systems are built directly into the ducts for return air. Particulates are trapped while air moves through the ductwork, allowing for thorough filtering. Homeowners have four major options in whole-house filtration and air cleaners:
- Flat filters – All forced air furnaces employ an elementary version of whole-house filtration. If your home has a forced air system, you can convert it to one that’s much more efficient. The filters are meant to protect the furnace. These might eliminate some airborne pollutants, but they don’t filter microscopic particulates. When clogged, they quit working and stress the furnace. Pleated filters are thicker and somewhat more effective alternatives that use the same space as flat filters. Electrostatically charged pleated types capture allergens more efficiently. All filters in this class should be checked monthly and replaced when dust and dirt has begun accumulating on the filter.
- Extended media filters – These units contain a stack of filters approximately 8 inches thick, with segments overlapping accordion-style. The filter unit is large, so it must be plumbed into the ducts by an HVAC professional. The filter inside the unit requires annual replacement.
- Ultraviolet filtering – With a UV light system, viruses and bacteria in the air are killed by ultraviolet light. Ultraviolet treatment is a popular choice in whole-house filtration and air cleaners and particularly in medical facilities. The typical UV filter is built into to the electronic precipitator as an added component.
- Electronic filters – Also called electrostatic precipitators, these are installed into the air ducts. A current of high-voltage electricity charges particles as air moves through. A collector plate with the opposite charge captures the particulates at the other end, similar to the way a magnet attracts metals. These are relatively effective for filtering smoke and other very small particles.