Dryers are sold in both electric and gas-fired models. The drying process consists of tumbling clothes, heating, and airing them. While gas dryers generally use less energy than electric models, and therefore are less expensive to operate, gas dryers usually require a higher first cost to buy and install. This is because gas dryers require both a gas line and vent pipe to the outside.
Also, older gas models may have continuously operating pilot lights, which waste energy. Now newer gas dryer models must have electronic ignition systems rather than pilot lights.
When considering the purchase of a new dryer, look for the feature of a dryness sensor that automatically turns the dryer off when it detects the desired level of dryness.
Automatic Dryer Shut-Off
For quite some time dryers used a wind-up timer switch to shut-off the dryer. It was up to you to guess and then set the number of minutes it would take to dry the clothes before pushing the start button. If, at the end of the minutes you set, the clothes were not dry enough, you would have to repeat the cycle. This tended to waste energy as often the clothes would be over dried. Newer models with automatic dryer shut-off can save quite a bit of energy. It also prolongs the life of clothing by avoiding being over-dried.
Different makers offer different types of sensors. Those that detect moisture in the drying drum seem to be the most effective, however they also have a higher price. Others that sense the exhaust air temperature are lower in cost and seem less accurate. Any sensor type is better than no sensor or just using a timer. Energy savings on the order of 10 to 15 percent are typical.