AC in the Attic Frustration

Here are some installation opinions from the northeast.
While attic installation of an air handler does present a few problems if installation is done properly and ductwork is sealed there is no reason that an attic installation cannot be a good fit especially if you don't like sweating to death upstairs in the summer, but you let me know what you think.

An attic is no place for a heating unit


Q.I have a gas furnace in my attic, where it was installed some time ago in the house that was built in 1937, with 3,000 square feet of living space. It is not heating very well, and two dealers offered ideas: One suggested installing a new hot-air unit fired by gas. Another suggested hydro air, a boiler in the attic that heats hot air that is blown into the second-floor living area. What should I do?

LAURIE, from Newton

A.Here we go again, when designers and contractors are putting air-conditioning units (not compressors, thank goodness) and heating units into attics. Generally, the idea is to share the space in large houses, with one unit in the basement to serve the first floor, another in the attic to serve the second and higher floors. In the Handyman's opinion, it is not a good idea, and in both cases these units should be removed from the attic.

In Michael Keegan's house, the air-conditioning unit (not a compressor, which should remain outdoors) is a distributor, with air flowing over cold coils and cooled as it is distributed to the house, or at least to the second floor. The problem is the unit is releasing a lot of water vapor into the attic, where it condenses on the cool ceiling and allows mold to grow. These units are usually airtight, but a leak may have occurred to allow that water vapor to escape. That can be fixed, and I suggest Mr. Keegan contact the dealer to get it fixed.

It would be better to relocate the unit to a proper room on the second floor, where excess water vapor could be exausted. Some engineers feel there is enough ventilation in an attic to handle the heat or water vapor, but the Handyman is not convinced this is so.

Ms. Laurie's problem is similar, but with a furnace that is not working very well. A good dealer might be able to fix that, but better would be to relocate that furnace, even if it has a power vent through an attic wall or through the roof. You can insulate the furnace, but you cannot insulate an open gas flame. Therefore, sooner or later, the unit will pump out a lot of water vapor and possibly heat, causing possible growth of mold, and possibly ice dams.

gas furnace with a power vent could be located on the second floor. If the house is big enough, this should not be a problem.

more stories like this Finally, most houses are not so big that they need two heating or two air-conditioning units. A lot of big houses are heated and cooled by one unit. That may sound old-fashioned, but it works better than some of the new-fangled ideas that are floating round these days.