Do It Yourself: Attic humidifier may be risky and unnecessary

Q. We have been getting conflicting advice about a humidifier in the heating-air conditioning system located in our attic.

The installer of our system recommended the humidifier and it has worked fine for a couple of years but several technicians have advised us to shut off the water to it. Is there really a significant risk of flooding?

A. In my opinion, the attic humidifier is not only risky but might well not be necessary.

Any leak or malfunction in the pipes or humidifier could cause water to be released in the attic, damaging insulation, the ceiling below and possibly ruining other areas of the house. I would definitely shut off the water and, if possible, have the water pipe and humidifier removed entirely from the attic.

I have never understood why some contractors install water-using equipment like this, sometimes including tank-type water heaters, in attics. Beyond that, I think humidifiers are sometimes installed and used in homes where they are not needed, and where they can sometimes do more harm than good.

Many modern homes are sealed so tightly to save energy that the relative humidity inside the home is excessive even without a humidifier. Showers and baths, cooking and laundering pour copious amounts of moisture into the home’s air, and if not properly vented outdoors this moisture can raise the indoor relative humidity well above the 45 percent that is considered ideal by many experts.

Excessive relative humidity can lead to such problems as mold and mildew, condensation on cold surfaces, even structural damage to the house. You can measure the relative humidity with a hygrometer or moisture meter, available at some home centers in a hygrometer-thermometer combination.

If you feel you really need a humidifier in winter to improve comfort, I’d consider a portable unit that can be used in the areas where more moisture is most needed.

Q. I recently discovered that my house, built in 1957, has an asbestos covering on the heating ducts in the basement. It is in good condition and basically fused to the ducts.

I had three contractors check it and got these options: Remove the asbestos-covered ducts and replace them, which would be very expensive. Conceal the ducts with ceiling tiles. Cover the ducts with another material and install ceiling tiles.

I worry about the asbestos if I try to sell the house. What do you advise?

A. It must be your decision, of course. The only bright spot in this quandary – which is faced by many owners of older buildings, when asbestos was used in many building materials – is that the Environmental Protection Agency advises that asbestos in good condition is best left alone.

You can find this advice in the EPA publication “Asbestos in Your Home,” which you can access on the Web at www.epa.gov/asbestos/pubs/ashome.html.

Asbestos is not considered a hazard unless it is in poor condition or is broken up so that particles get into the air and are breathed. Unfortunately, there has been so much publicity about asbestos-related health problems that many people are terrified of having it around at all, good condition or not.

That fear would be a factor if you tried to sell the house, since you would probably be required to disclose the presence of the asbestos to prospective buyers.

In some states, if the asbestos is considered to be in poor condition and to pose a health hazard, you might be required to have it safely removed before you can sell. If only disclosure is required, you might be fortunate enough to find a potential buyer who understands that asbestos in good condition is not hazardous.

My advice is to first consult with an experienced real-estate lawyer or real-estate agent in your area. Also read the EPA publication “Asbestos in Your Home.” When you have done those things, you will be better prepared to make a decision on what to do about the asbestos.