Do Air Filtration Systems Work and How Much do they Cost?

More and more the quality of indoor air is becoming a priority for homeowners. In addition to choosing low-toxic finishes and furnishings, air filtration systems can help improve indoor air by removing allergens, dust and particles. There has been a considerable surge in the air filtration industry but do these home accessories work and at what cost?

There are two basic types of air filtration systems: whole-house filters and portable filters. Whole-house filters are the most efficient but only work with forced air heating and cooling systems. And they only work when the HVAC is engaged in circulating conditioned air.

Still, these filters are an effective way to reduce indoor air pollutants as they service the entire home. There are four basic types of whole house filters: flat, extended media, electronic (ionic) and UV (ultraviolet).

Flat filters are common with most forced-air systems. They are basically a fiberglass mat that captures large particles. These filters should be changed every 2-3 months to both keep the air clean of debris and keep your furnace running efficiently - when these filters become clogged your furnace will work overtime. These filters are basic and while they can help filter the air they aren’t as effective as some of the other choices. However, they are inexpensive – under $20 each.

Extended media filters are a step up from flat filters but work in a similar fashion. They are a constructed of a series of filters that are integrated into the ductwork from the furnace. They are more effective at clearing smaller particles from the air but come with a higher price tag, up to $600 installed. These need to be changed yearly and replacements run around $50 each.

Ionic filters use an electric charge to create static and attract air-born particles. They can be effective on allergens, bacteria and some odors like smoke. There are two drawbacks to this type of air filtration system. First, not all the charge particles find their way to the filter. These pollutants, now charged, can be attracted to interior finishes and furniture.

The second consideration with ionic filters is that the process can emit ozone, a respiratory irritant. This quality has led many consumer advocates to advise against them. While some research shows these filters to be highly effective at clearing the air, other reports find there is little proof that they can do so without producing unhealthy ozone levels. These systems don’t require filter replacement but the collector plates must be cleaned regularly to keep the system working. They can cost up to $1,000 installed and run small costs for electricity usage.

UV filters are designed to control germs and viruses and they can be effective. They work by releasing a short-wave ultraviolet light that acts as a germicide to kill micro-organisms like bacteria, germs, viruses and mold. They are not as effective on allergens – they remove some but less than other systems. They can be added in to existing HVAC systems for $600 - $800.

If you don’t have a forced-air heating and cooling system, you can opt for portable filters that can be moved around the house. They come in similar versions as whole-house filtration systems but are more readily available with HEPA (high-efficiency particulate air) filters. Portable HEPA filtration is an excellent choice if you are mainly concerned with clearing allergens from the air. Depending on the size, a portable HEPA filter can range from $100 for small models up to $1,000 for large capacity versions.

Some portable filters are hybrids either HEPA/Carbon or UV/HEPA. These combine some of the best technology for both allergen removal and germ mediation. Hybrids run between $400 -$600 but can be worth the extra cost over a HEPA only model. HEPAs run operational costs for electricity and filter replacements, up to $100 each. UV portable filters require replacement bulbs which can cost up to $100. With any model, check the replacement parts frequency required and the price of replacement parts.