Air Cleaners & Filtration Systems

Whole house or room size?

Indoor air quality is determined by the materials that make up your home; where and what type of pollutants exist; and whether your home is adequately ventilated.

Use source control to identify specific problems such as excess moisture, mold, materials that "off-gas", or dusty, allergen-dense conditions. Locate moisture problems, such as a leaky pipe under the kitchen sink, and correct for relatively low cost before they get out of hand. Choose low-VOC (volatile organic compound) paints or replace dust-catching carpet with green, sustainable linoleum flooring to improve indoor air quality.

Improve ventilation with efficient fans and exhaust systems to quickly remove airborne moisture, particulates, and pollutants by expelling them outside. This can be problematic, however, because of heating and cooling costs.

When you've done what you can to remove identified problems and improve ventilation, the third approach is selecting an air cleaner. You have two basic choices: a central filtration system that is added to the HVAC system, or a portable room-size unit. (The small, table top machines don't move enough air to be very effective.)

Whole house air cleaners

Despite the appeal of having a single device clean and filter your home's air, the research regarding whole house air cleaners indicates that they simply do not work as well as one would wish. These central filtration systems, which are located in the unducted return air plenum, simply have a hard time cleaning the air as efficiently as the room-size units.

The primary issue is that even the best HEPA central air cleaner works only when the furnace fan is blowing. This translates into additional energy costs which could easily become an issue for many home owners.

Whole house air cleaners are also relatively expensive, though if you or members of your family have significant allergies, the purchase and installation cost may easily be more than worth it.

Homeowners who have chosen whole house systems often do so because noise levels are reduced when the system is placed in a utility closet or basement.

A licensed HVAC contractor is required for installation in most cases and adequate space is needed because these are typically large units. The advantage is that they can usually be removed easily, so you can take it with you if you move.

Portable, room-size air cleaners

Of the choices, portable room-size air cleaners are regarded as the best solution for the money. Costing about 25–30% of a whole house filtration system, a good portable system with a HEPA filter can perform highly efficient air exchanges and capture particulates as small as 0.3 microns.

Portable systems are somewhat noisier than central systems, but are often not much more noticeable than a room fan.

Two air cleaning systems strategically placed can often provide more air cleaning capability than a central system. No installation is required and the better systems generally carry a 5-year warranty.

Regardless of the type of air cleaner used, routine maintenance is essential to its efficiency. Also, proper placement that allows a free flow of air in and out of the device near known pollutant hot spots ensures better performance and improved air quality. Systems that produce ozone, a known lung irritant, are not recommended.

There is no perfect air cleaner so efforts to continuously improve source control and ventilation are key to maintaining a high level of indoor air quality.


Do you need a contractor with experience installing whole house air cleaners? If you want a qualified professional, check Contractor Nexus for the expertise you need.

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