As people become more health conscious, indoor air pollution is getting as much attention these days as outdoor air pollution.
A recent Environmental Protection Agency study concluded that a person`s exposure to indoor air pollutants can sometimes be greater than to pollutants outside the home.
Because indoor air is more confined, it is basically a stew of pollutants: Some of the things found floating in an average home include pollens, molds, bacteria, mildew, pet dander, spores from household plants, dust mites, cigarette smoke, wood smoke, cooking smoke and fungi.
While outdoor air pollution is easy to spot, indoor air pollution is mostly invisible to the eye. But sunbeams in a home, for example, wouldn`t be visible if it weren`t for the suspended airborne particles that scatter the light in the beam`s path.
According to Honeywell officials, those visible particles that scatter a sunbeam`s light actually amount to only about 1 percent of all the particles floating in a home`s air.
”The stuff that settles on your furniture doesn`t really bother you,”
said Mark B. Sims, director of indoor air quality for Honeywell`s residential division. ”It`s the stuff that stays suspended in the air that you can breathe in and can cause you problems: pollens, molds, bacteria, etc.”
The electronic air cleaner
As an attempt to clean up a home`s air, electronic air cleaners have become an increasingly popular fixture in many homes in recent years.
They often can make a major difference in indoor air pollution: Efficient electronic air cleaners are designed to remove more than 95 percent of particles in the air. They can remove 10 to 20 times as many particles as the standard furnace filter, Honeywell officials said.
For example, an electronic air cleaner can eliminate a particle as small as 1 micron. As a benchmark, some 750 microns would fit snugly on the head of a pin.
”People are more conscious about health issues today and want the cleanest environment possible, especially when it comes to their homes,” said Tony Viola, office manager for Air Cleaning Specialists in Chicago, which sells electronic air cleaners. ”The whole issue of secondhand smoke, or passive smoke, has also made people more aware of the options out there.”
”Our (electronic air cleaner) business has doubled in the last three years,” added Sims. ”People are very concerned about clean air today.”
There are four basic benefits to an electronic air cleaner, said the officials.
The major advantage is an increased home comfort level. Electronic air cleaners remove offensive and irritating air particles such as pollen, dirt, dust, grease, micro-organisms, etc. And that makes a home feel more comfortable.
That comfort level is a hard thing to measure, said the officials. But it`s something that many homeowners with electronic air cleaners quickly get used to.
”A lot of our consumers know when their air cleaner stops working, or even when it needs cleaning,” said Sims, ”by the quality of the air inside their homes.”
The second advantage of electronic air cleaners is health-oriented: For those people suffering from allergies, asthma and other illnesses, electronic air cleaners can help remove irritants such as pollen, spores and tobacco smoke.
Hence, some doctors actually prescribe electronic air cleaners for certain patients suffering from a respiratory problem, which may make an electronic air cleaner tax-deductible.
Electronic air cleaners can also help cut down on housework by keeping dust and other particles off furniture, draperies, walls, carpets, etc.
Finally, electronic air cleaners can also help keep your home`s heating and air-conditioning system cleaner and working at a more efficient level. For example, Sims said that clean coils on a heating/air conditioning system can save up to 10 to 15 percent in operating costs as they perform at a peak level.
”An electronic air cleaner can especially benefit the higher-efficiency heating and air-conditioning units,” added Herb M. Uhlhorn, general manager of Authorized Service & Parts in Evanston, which also sells electronic air cleaners.
How they work
The scientific term for an electronic air cleaner is actually two-stage electrostatic precipitation.
After air is drawn into the unit through a fan, large airborne particles are trapped on a filter screen. Smaller particles then pass by charging wires, where they are hit with an electrical charge.
Like magnets, these charged particles are then attracted to a collecting plate; negative-charged particles are drawn to a positive-charged plate, while positive-charged particles are drawn to a negative-charged plate.
This is basically a process called ionization, which is also thought
(although not proved) to produce a calming effect in a living space.
The clean air is then circulated back into your home. The collecting plates are removed and cleaned every month or so to remove the collected particles. They are no harder to clean than an air-conditioning unit filter. Honeywell officials, for example, recommended simply cleaning their collecting cells in a dishwasher.
A number of manufacturers produce electronic air cleaners: Honeywell, Lakeair, Smokeeter and Bionaire, among others.
Electronic air cleaners come in two basic types: a central unit that plugs into your home`s existing forced-air heating and air-conditioning system; or portable or table-top units that can be moved from room to room.
There are certain advantages to each type of unit.
Central-unit electronic air-cleaner systems, for example, provide cleaning to an entire home. They can also be activated automatically. And because they are installed into the heating and air-conditioning system, they take up no space.
Most heating and air-conditioning companies can install such units;
installation takes less than a day.
Portable units can be used in homes that do not have a forced-air system. They can also be transported from room to room, wherever there is a problem with air quality.
They are often the size of a breadbox and come in a number of finishes.
Portable units may simply be placed on top of a table or bookcase, although Viola recommended installing them in a central location for optimum performance. ”We suggest you put the air cleaner up high, so you can create an air pattern in the room,” he said.
”In a living room, for example, put it against the longest wall right about the middle of the wall. If you also put it up high, nothing impedes the air flow.”
Such an installation, said Viola, would simply entail putting a bracket on a wall.
The obvious limitation of portable electronic air cleaners is the amount of air they can move-usually about 10 to 300 cubic feet of air per minute, depending on the speed setting. A central unit could move more than a thousand cubic feet of air per minute.
Central units range in price from $500 to $1,000 installed, depending on the size of the home. Of course, installing an electronic air cleaner when replacing a furnace or building a new home makes the unit more cost-effective.
Portable units can begin at $200 and cost as much as $600, depending on cleaning capacity and features.
Features on electronic air cleaners are fairly limited. Certain models offer an indicator light that alerts a homeowner when the filter needs to be cleaned. Others have various speed settings to allow it to accommodate itself to a home`s conditions.
There are also a couple of things to keep in mind when considering an electronic air cleaner, said the officials.
For example, although they do clean the air, they do not clean the house. While an electronic air cleaner will remove some dust from a house, it will not eliminate dust, said Uhlhorn.
”Dust particles come from a lot of places,” he explained. ”A lot of people think once you put an electronic air cleaner in, you`re not going to have any dust lying around. That`s an impossibility. So you still have to dust.”
And the installation of an electronic air cleaner may not produce an immediately noticeable difference.
”It`s somewhat of an intangible thing at first,” said Sims. ”But most people become sensitive to the quality of air and the comfort level that`s produced by an electronic air cleaner.”
