Today's Technology And You

Today's
TECHNOLOGY AND YOU

Thermostat that does the thinking

Q: We want to improve our comfort and lower our heating and cooling bills. New setback thermostats are much cheaper now, but are they any easier to program? How much will one cut my utility bills? - E. H.

A: Prices of "smart" programmable thermostats have dropped substantially while the quality has improved and the array of features has expanded. Even if you are all thumbs when it comes to operating electronic devices (your VCR still flashes 12:00), you will have no trouble programming one of these new smart thermostats.

Most smart thermostats will pay back their cost with utility bills savings in several months. Depending on your climate, a double eight-hour 10-degree winter setback will save from 15 to 35 percent and a double 5-degree summer set-up will save from 10 to 30 percent.

What is nice about these newer smart thermostats is that the savings come without the sacrifice of comfort or convenience. In fact, comfort is often better because these thermostats hold room temperatures evenly. The best ones can maintain the room temperature within one degree of the thermostat setting.

In the winter, you can set the smart thermostat so your house is toasty warm when you go to bed. The thermostat automatically allows the house to cool down overnight while you sleep. The computer inside the thermostat heats up the house again just before you awake in the morning. You never even sense that the temperature has changed, yet you saved a lot of money.

New smart thermostats are simple to program. It takes about five minutes. If you are really inept at this, choose one with a built-in setback program. You just push one button for a basic generic winter/summer setback schedule. With battery backup and "armchair" programming features, the thermostat can be snapped off the wall and conveniently programmed anywhere.

There is a simple color-coded four-wire hookup for the majority of thermostats. Since thermostats operate on only 24 volts, they are safe to work on. A heat pump thermostat has several more wires to control the reversing valve and backup auxiliary heat. I have an all-electric house with a heat pump and it took about 20 minutes to install the thermostat.

If you have a heat pump, do not manually lower the temperature setting on your standard thermostat each night. Doing this may cause the backup auxiliary electric heaters to come on in the morning to reheat the house. This ends up using more electricity than you saved overnight.

Smart heat pump thermostats have special circuitry to allow the house to reheat slowly in the morning without kicking on the auxiliary heater. If it reheats too slowly on a very cold morning, it will cycle the auxiliary heaters on if needed.

Some smart thermostats, like the one in my house, have an instant override button to temporarily bypass the set schedule without reprogramming it.

There are several additional features to consider. Consider a backlit digital display if you have difficulty seeing LCD displays. Some models have a filter-change light to signal you when it is time to change it. Forgetting to change a filter turns your heating and air-conditioning system into an energy guzzler.

Write for Utility Bills Update No. 783 showing a buyer's guide of nine smart thermostat manufacturers listing number of daily time/temperature schedules and temperature settings, features, prices and a chart showing the savings. Please include $2.00 (with checks payable to "Jim Dulley") and business-size SASE, and send to Jim Dulley, Illinois Country Living, P.O. Box 3787, Springfield, IL 62708.

James Dulley is a mechanical engineer who writes on a wide variety of energy and utility topics. His column appears in a large number of daily newspapers.

6 ILLINOIS COUNTRY LIVING NOVEMBER 1996