10 Energy Efficiency Myths

With all of the buzz and hype surrounding energy efficiency these days, there is a lot of incorrect information floating around. The following list will hopefully clear up some of the energy efficiency rumors out there. For even more myths, visit http://hes.lbl.gov/hes/myths.html

1. Switching to electric room heaters will reduce your energy bill.
This is true only under some circumstances. If you have central electric heating, the using room heaters will most likely save you money. But, if you have central gas heating (which is far cheaper per unit of useful heat) you can easily match or even exceed your heating bill by switching to electrical units.

2. Duct tape is good for sealing ducts.
Unfortunately, laboratory research has concluded that duct tape has very low durability when used to seal ducts. On new installations, tape may fall off due to poor surface preparation, because ducts are installed in dirty and dusty locations and conditions. On older systems, the tape falls off as it ages and the adhesive dries out and tends to wrinkle.

3. When my appliance is turned off, it's off.
In fact, we've found that most devices continue to consume power when they're switched off, sometimes as much power as when they're on!

4. Installing foam gaskets in electrical outlets will significantly reduce air leakage.
Measurements have shown that less than 1% of a home's air leakage is due to outlets.

5. Turning up (down) the thermostat will make your home get warm (cool) faster.
It's tempting to think of a thermostat like a water tap, i.e. the wider you open it the more water (heat/cool) will come out. In reality, it works more like a light switch in that if it's "on" the same amount of light (heat/cool) will come out.

6. Leaving lights, computers, and other appliances on uses less energy than turning them off and makes 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 drastically reduced their useful lifetimes, these problems have been largely overcome through better design.

7. Electric heating is 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, etc.) being lost in the process. This is why electricity is so much more expensive for the consumer than direct fuels.

8. Cleaning refrigerator coils saves energy.
While this seems intuitively logical, and very small savings may indeed arise, the few efforts to actually measure this effect have typically come up empty-handed. This is a classic example of a widely held belief based on assumptions rather than measurements.

9. Buying an efficient air conditioner or furnace will 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 1/3 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 insulation, windows and many other energy-efficiency upgrades.

10. Energy efficiency and energy conservation are one and the same thing.
Well-intentioned information campaigns during oil crises of the 1970s created a lot of confusion about how to save energy and even about how to talk about saving energy. Energy efficiency means getting a job done with less energy. This could be lighting a room, cooling a house, or refrigerating some vegetables. The things made possible by using energy are sometimes called "energy services," e.g. illumination, comfort, or food preservation. Energy conservation, on the other hand, means reducing the level of services, e.g. reducing lighting or comfort or turning up the temperature of your fridge. Reducing service levels (conservation) does not necessarily mean sacrifice, however. For example, many spaces have more than enough light by current-day standards, water heater temperature are set too high, etc. Consumers have the option of improving energy efficiency (e.g. by purchasing better appliances) and/or reducing service levels, but lowering the quality of life is not a prerequisite for reducing energy demand.