I don’t usually test products for more than a week, but I decided to give the Holmes HEPA room-air purifier several weeks before I wrote about it.

Why? Indoor-air quality. You can buy a dream house but if it doesn’t breathe properly, you’ve wasted a lot of money and are probably making yourself sick to boot.

We have a whole-house air cleaner that has brought a reduction in allergy suffering as well as our new ability to grow indoor plants during the late fall and winter.

But the whole-house cleaner works in concert with the heating and air-conditioning systems, and thanks to a drippy and cool spring that hasn’t demanded either system, the cleaner has been off.

On sunny days, I open the skylights and windows in the second-floor master bedroom to get the air circulating and keep the area cool. But pollen fills the space through the openings during the day, and sends us running for the Claritin so we can sleep at night.

The people at the Holmes Group wanted me to try out the Harmony HEPA air purifier, designed for a room about 14 by 11 feet – about the size of our sleeping area and a bit more.

The high-efficiency particulate air filter in the Harmony is made of tightly woven fibers designed to remove 99.97 percent of all airborne particles 0.3 microns or larger.

The Harmony draws contaminated air (dust, pollen, pet dander and mold) through the filter, then distributes clean filtered air in the room.

On the highest setting on days when the sun doesn’t beat so intensely on our insulation-starved roof (there should be 6 inches, but it has only 3 1/2 inches of fiberglass), I can use the Harmony as a fan as well as an air cleaner.

Let me explain the experiment. On days I knew it would be sunny and I was working from home part of the day, I’d open the windows and skylights from 9 a.m. until 4:30 p.m.

Then I closed all the openings and turned on the Harmony to make sure that the air was cleaned by 11 p.m.

Since May and early June were so rainy, this meant I was able to conduct the experiment for only nine days.

Fortunately, there was one windy day in which yellow dust from trees covered the screens on the skylight and the windows, so I knew there was pollen getting in.

The only control for this experiment was the two or three days in late April in which I left the windows open all day and we didn’t use the filter. The allergies were murder those days.

I’m no scientist, but from my experiment it appears as if the Harmony did what it was supposed to do.

Price: $200 to $250, depending on the model. Information: www.holmesproducts.com. Available at home centers and department stores.

While we’re on the subject

If you’re remodeling and have allergies or are prone to reactions to cleaners or other materials, the National Association of the Remodeling Industry has some suggestions:

• Tell your contractor during your first meeting about any allergies.

• Seal off the area to be remodeled with plastic sheets, and leave them up until clean-up is complete. When sheeting is removed and discarded, avoid carrying it through the home.

• Close all vents in the room being remodeled so dust won’t travel though the air ducts. Open windows at least a crack and set up a fan to exhaust air toward the outside.

• Keep family pets out of the work area. Vacuum and sweep the area daily.

• Change your furnace filter often since it will pick up more particles than usual.

• Plan for removing debris. Using a chute out the window is ideal since it will eliminate the possibility of tracking materials through the house.

• Consider a hard floor such as wood, ceramic or slate instead of carpeting, which is an ideal home for dust mites, a leading cause of allergies.

• If you choose hardwood floors, discuss the effects of fumes they may emit. Consider staying out of the home for a couple of days after installation, to let it properly air out.