Comfort Line - Questions and Answers

This quarter our question and answer segment details some common myths about energy and energy savings. This material was compiled and produced by Evan Mills of the Lawrence Berkeley National Laboratory in Berkeley, California

Will buying an efficient air conditioner or furnace automatically reduce my energy bill?

This is true to some extent, but you won't realize all the possible savings if the equipment is not sized or installed properly. Studies have shown that typical air conditioner and duct systems are improperly installed, wasting one-third or more of the energy used by the air conditioner. New and replacement equipment (and ducts) need to be properly designed and installed to realize all the possible savings. The same caveats about proper installation hold true for the installation of boilers and many other energy efficiency upgrades.

Does leaving lights, computers and other appliances on use less energy than turning them off and on repeatedly, and make them last longer?

The small surge of power created when some devices are turned on is vastly smaller than the energy used by running the device when it's not needed. While it used to be the case that cycling appliances and lighting on and off significantly reduced their useful lifetimes, these problems have been largely overcome through better design. The rule of thumb today is: Turn off the lights when you leave the room, and use the power management software that comes with your computer and monitor.

Will insulating the ceiling just cause more heat to leak out of the windows?

Adding insulation to one part of a home won't increase the "pressure" on heat losses through other parts. However, it is true that poorly insulated areas will be the major losers of heat, and that they often merit attention before improving already well insulated parts of the home. To best insulate a home, large and small leaks must be addressed.

Is electric heating more efficient than fuel-based heating?

It's true that all, or almost all, of the electricity that goes into an electric heater is transformed to useful heat in your home. However, making electricity is an inefficient process, with as much as two-thirds of the input energy (coal, natural gas or oil) being lost in the process. This is why electricity is typically so much more expensive for the consumer than direct fuels.