Home Air Cleaners Butte MT
Butte , MT
Great Falls, MT
Billings , MT
Mechanical and electronic air cleaners can remove pollutants and improve your home's indoor air quality.
Environmental air pollution from factories, power plants and chemical plants gets a lot of press coverage these days, but some of the most offensive sources of indoor air pollution can be right in your own home. This time of year, when most homeowners in cold climates keep windows and doors shut tight, there are even higher concentrations of indoor air pollutants that can affect the health of homeowners and their families.
Indoor air pollutants can be solid, liquid or gaseous, and can include airborne pollutants like pollen, dust and tobacco smoke; volatile organic compounds (VOCs) emitted from drying paint, open cleaning products and out-gassed from carpeting and furniture; and bio-aerosols, which are microscopic organisms such as mold spores, mildew, bacteria and pet dander.
To minimize indoor pollutants, you can take steps to remove or control sources of the pollutants. In addition, consider installing filtering equipment that will help clean indoor air.
The most direct and inexpensive way to improve the overall quality of air in a home is to eliminate or minimize sources of pollution (see Common Sources on page xx). After that, homeowners can improve ventilation by opening windows when weather permits, using heat exchangers in hot-air systems, and installing kitchen and bathroom fans to remove humidity and odors.
Another way to improve air quality is to upgrade the filter in your home's central HVAC system to a higher-efficiency version that can remove a greater percentage of solid particulates and smoke. Homes with central HVAC systems typically come with inexpensive inch-thick flat or panel fiberglass filters of low packing density. But generally these are effective only in removing larger-sized particles, and not microscopic particles that can be as tiny as 0.001 microns. (An average human hair is about 250 microns in diameter.)
Designed to be disposable, these filters cost just a couple dollars each but capture only about 10 percent of the small particles. Upgrading to a more expensive disposable or washable pleated medium- or high-efficiency filter improves capture rates, but the highest removal rates of indoor particulates are achieved with either room or whole-house air cleaners.
Typically, standard air filters are less than 20 percent efficient at trapping or filtering particles, while air cleaners are more than 20 percent efficient. Available from a number of manufacturers, air cleaners are classified by how they remove particulates. The two main types are mechanical air cleaners, which use medium- or high-efficiency filters and a fan to draw the air through, and electronic air cleaners, which use a generated electrical field and a fan to trap charged particles.
Similar to a typical furnace filter, though usually much thicker, a mechanical air cleaner has a powerful fan that forces air through a medium- to high-efficiency flat or pleated filter, which uses a woven material with increasingly smaller openings and sometimes a viscous substance to strain out particulates.
The most effective type of filter is a HEPA (high-efficiency particulate air) filter, made of densely packed submicron glass fibers formed into a pleated surface. HEPA filters have a minimum particle removal efficiency of 99.97 percent at a particle size of 0.3 microns. As a result, they are effective at removing dust, pollen, smoke and some microorganisms from the air, but generally not gases.
Because of their density, HEPA filters can restrict airflow in an HVAC system, so they're generally used as standalone portable units. However, a number of manufacturers sell HEPA-type filters for HVAC systems. These units use the same type of filtration system and are nearly as efficient as HEPA filters at removing particulates, but with a lower restriction to airflow.
Non-HEPA mechanical air cleaners have the same problem -- they cannot be installed in the filter slot of a home HVAC system due to their thickness and the fact that the system's fan is not powerful enough to generate the necessary airflow. However, they can be installed as an integrated fan-and-filter unit in a home's duct system or used as standalone air cleaners.
Because they require a large fan motor to move air, mechanical air cleaners can add to your energy costs, and the filters can be expensive to replace. On the upside, mechanical air cleaners do not produce ozone, a gas that can cause respiratory problems, irritate the eyes or parch the throat. Ozone production, however, can be a problem with other types of air cleaners.
There are three types of electronic air cleaners on the market: electrostatic precipitators, ionizers and ozone generators.
Electrostatic precipitators draw air into the unit past a prefilter screen that traps larger particles and charges them as they pass an electrical field. The charged particles are attracted to and captured on a series of reverse-charged flat plates, where they accumulate until the plates are cleaned. A fan drives the airflow, though it is much smaller and less costly to run than a fan in a mechanical air cleaner, and it is quieter as well.
Ionizers, available only as portable units, use static electricity to charge particles in the air. Generally there is no fan to aid air circulation. While some of the units have a collector plate to attract the charged particles to the unit, others don't, leaving the charged particles to become attracted to room surfaces, such as drapes, table tops, walls and floors, soiling them.
Ozone generators clean the air by producing ozone, a gas that can cause respiratory and eye irritation, or parch the throat. They are not recommended for use in a home.
All ionizing cleaners produce small amounts of ozone. To limit ozone emissions from electrostatic precipitators and ionizers, clean them.
In addition to filtering pollutants, some air cleaners also contain absorbents and/or reactive materials, such as activated carbon filters that help trap and absorb odors, further freshening the air.
Your first decision should be whether to install a whole-house air cleaning system or to use one or more portable air cleaners. Whole-house systems require a central forced-air HVAC system. Homes lacking a central duct system call for room units.
Depending on the model, room air cleaners can handle up to about 500 square feet. They range in size from tabletop units to units that sit on the floor. Whole-house air cleaners require professional installation in a home's central air duct system, on the return side of the duct system.
There is no universally accepted standard by which to measure the effectiveness of air cleaners. However, homeowners can look at the manufacturer-stated efficiency of the device (if available), which notes the percentage of pollutants removed as the air passes through the device, and the clean air delivery rate (CADR), if indicated. A product of the unit efficiency and airflow rate, the CADR measures the number of cubic feet per minute of air the device cleans of a specific material (such as smoke particles).
The Association of Home Appliance Manufacturers provides ratings on room air cleaners by 25 manufacturers of room air cleaners who voluntarily participate in AHAM-sanctioned independent testing to verify the CADR and have earned the AHAM seal. You can view a list of participating manufacturers by visiting http://www.cadr.org/consumer/faq.html.
As a rule of thumb when selecting the size of a portable air cleaner, choose a model that can replace the air in the room at least two or three times each hour. For a central system air cleaner, aim for a size that can handle a minimum of 0.5 air changes per hour, a rate that is the minimum necessary to ventilate a home continuously under most conditions.
When comparing two units operating at the same efficiency, the unit with the higher flow rate is a more effective solution. However, sometimes placing a less efficient unit closer to the source of a pollutant can be as effective as a more efficient unit at a further distance.
For continued optimal performance, all air cleaners should be maintained according to manufacturer directions. Filters should be inspected periodically and cleaned or replaced when clogged or dirty. Proper maintenance will ensure your air cleaning system is doing its job by helping to make your home a healthier place to live.
New York based writers William and Patti Feldman are frequent contributors to Smart HomeOwner.
Standard air filters are less than 20 percent efficient at filtering out particles, while air cleaners are more than 20 percent efficient.
Some air cleaners contain absorbents, such as activated carbon filters that help trap odors, further freshening the air.