Home Improvement : Balancing Registers Keep Temperature Even

QUESTION: There are several rooms in my house that never stay cool enough in the summer. Is there an inexpensive method to control the amount of air-conditioned air going to various rooms throughout the day?

ANSWER: Especially in the summer, because the sun moves far from northeast to northwest, the cooling needs of each room varies throughout the day. This makes it very difficult to maintain a comfortable temperature in each room. A room that is too cool in the morning gets too hot in the afternoon.

When one room gets too hot, you often set the central air-conditioner thermostat lower. Each degree it is set lower can increase your electric bills by 2% to 5%. By balancing the cooling air to rooms where it’s needed, you can set your thermostat higher, be comfortable and reduce your electric bills.

One effective balancing method is to install simple (no electric power) automatic-balancing floor or wall registers in the warm or cold rooms. These registers sense the temperature in the room and automatically open or close to maintain the desired room temperature. There is a temperature adjustment knob on each register.

For example, if a kitchen is too cold in the morning, the register automatically closes to reduce the cooled air blowing into the kitchen. This forces more cooled air to other rooms that are too warm.

As the sun shines on walls and in windows in the afternoon, a bimetallic sensor spring inside the register senses the warmer temperature. It then holds the register vanes open to allow more cooled air to blow out into your kitchen. By installing these registers in several other problem rooms, the cool air is always directed to the rooms that need it most.

There is a specially designed switch inside the register so you can switch it from summer to winter operation. At the winter setting, it opens the register vanes when the room gets cold instead of closing them at the summer setting.

You can also install a very sophisticated zone control damper system in your furnace/air-conditioner ducts. These systems use electric servomotors to open or close dampers in each duct depending on the cooling or heating needs in each room or zone (group of rooms).

There is a separate wall thermostat in each room or zone which controls the damper in the duct leading to that room. You can install automatic computerized thermostats. These allow you to set different temperatures in various rooms throughout the day and night.

You can write to me at the address below for Utility Bills Update No. 412 listing addresses and telephone numbers of manufacturers of the automatic temperature-sensing floor and wall registers, computerized zone temperature control systems, product specifications, and low-cost tips for reducing your cooling costs. Please include $1.50 and a self-addressed business-size envelope.

Is It Worth Painting Old Refrigerator?

Q: I have a 15-year old refrigerator which is an ugly brown color. Does it make sense to repaint it or get a new energy-efficient model?

A: On average, refrigerators typically last about 20 years. The price to repaint a refrigerator is about $200 to $250. With only about five years of life remaining and considering its low efficiency due to its age, you are probably better off buying a new high-efficiency model now.

If you do plan to have your refrigerator repainted, there are three good methods, acrylic enamel, baked-on enamel and electrostatically applied enamel. All should give excellent results if applied properly.

Letters and questions to Dulley, a Cincinnati-based engineering consultant, may be sent to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.