Window units earn points for efficiency

Q. Our cooling bills are very high even though we keep the air conditioner set well up in summer. The central unit also does not cool our master bedroom well and we often resort to sleeping in a spare room. Would window air conditioners save us money and give better cooling?

A. A window air conditioner would almost certainly keep that bedroom comfortable and one or two other window units in strategic places could cut your cooling cost and improve comfort, assuming you turn off the central unit when using them.

The big advantage of window air conditioners is that it is possible to cool only the space you are occupying – a bedroom, family room, kitchen or whatever. Modern window units have quick response; it is possible to cool a hot room in less than an hour and keep in cool for as long as necessary.

Modern window air conditioning units are also more efficient than older ones, lighter in weight, smaller, and many are less expensive than comparable older models. Many also have remote controls, so you can turn the unit on and off or adjust the temperature without leaving your bed or chair.

Window units do have some disadvantages. They can be noisy, especially when the compressor is running. They fit best in double-hung windows (two sashes that slide up and down). They should be removed from the windows and stored when colder weather arrives, then lugged out and reinstalled when hot weather returns.

Window units must be securely fastened in place, since an intruder can easily push a loose one out of the way and crawl through the open window. They are banned in some developments as detractions from the appearance of the houses. Finally, they obstruct the view through the window and prevent the window from being opened and closed for ventilation in cool weather.

So you should weigh the pros and cons carefully before opting for window units, though I think the advantages far outweigh the disadvantages.

Q. Old bathtubs can be painted, of course, but paint only lasts a few years. Are there cost-effective ways to line a tub that will keep it looking good for a long time?

A. Tough, attractive liners made of acrylics and other plastics are available to fit virtually any old bathtub. The liners are molded to fit the tub exactly, providing a new surface that can last for 15 years or more.

Franchisers such as Re-Bath (www.rebath.com) claim that thousands of liners have been installed in hotels and apartments. Long-term warranties are available from some dealers.

Installations usually take only one day, but there can be a waiting period of several weeks between the time the tub is measured and the installation. Some manufacturers also offer matching tub surrounds made of the same durable materials.

Cost estimates for a tub liner range from about $700 to $1,000 – considerably more than a professional paint job, but still a great deal less than the cost of tearing out and installing a new bathtub.

Like most plastics, liners can be scratched or otherwise damaged. Some owners also complain that a thin film of water gets between the liner and the bottom of the tub, sometimes causing bad odors and mold. Plumbing problems such as leaks around the drain are also sometimes cited.

The best protection against any problems is a written warranty and experienced installers.

Q. We recently had a ridge vent installed on our older house. One contractor told us we should close off the gable vents in the ends of the roof because we can’t have both types of vents. Other contractors told us not to worry about it. What’s going on?

A. I agree with those who told you not to worry. If you have adequate attic insulation, the extra ventilation provided by both types of vents should be helpful.

Good attic ventilation is important year-round. In hot weather, it helps keep the attic cooler and can extend the life of your roofing. In winter, good ventilation helps prevent condensation on cold surfaces in the attic. Condensation can result in damp insulation, mold and even structural rot.