A useful collection of tools and information to help increase your energy knowledge.

True or false

Explore this page to prove or debunk common
energy-efficiency perceptions. The answers
may surprise you.

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Appliances and electronics don’t use energy when turned off

FALSE. Computers, printers, TVs, cell phone chargers and more may continue to consume electricity, when turned off, sometimes just as much as when they’re turned on. Consider purchasing a smart strip (more advanced than a traditional power strip) that cuts off power to appliances that are powered off.

Leaving CFLS on is more efficient than turning them off and on

FALSE. They should be turned off if the space isn’t going to be occupied for more than a few minutes. Modern CFLs draw a higher level of current during startup, but it lasts for less than a second, which is negligible compared to the energy used by leaving them on when not in use.

Duct tape works well for sealing ducts

FALSE. Laboratory research shows that duct tape does not adequately seal the joints in heating, ventilation and air conditioning ducts, and has a short lifespan. Instead, use mastic sealant or metal tape to get the job done right.

Bigger heating and cooling equipment is not always better

TRUE. When buying new heating and cooling equipment, proper sizing and quality installation are critical to your home's energy efficiency and comfort. Oversized equipment can cause reduced comfort and excessive noise. Oversizing can also shorten the life of equipment by causing it to cycle on and off more frequently than a properly-sized unit.

You should check your heating and cooling system’s filter once a month

TRUE. You should also have a pre-season checkup of your system by a licensed contractor in the spring and fall to ensure all parts are working properly, and to avoid early system failure. If your furnace is more than 15 years old, or your A/C unit is more than 12 years old, consider replacing it with a properly-sized, more efficient unit.

Leaving your computer on saves energy compared to powering it up and down

FALSE. If you're going to be away from your desk for a long period of time, and particularly after hours, you should turn off your computer, monitor and peripherals using a smart strip (more advanced than a traditional power strip).

Halogen lighting is energy-efficient

TRUE AND FALSE. While halogen lights consume less energy than incandescent bulbs, CFLs and LEDs are far more efficient.

Home attics have a substantial impact on your heating and cooling costs

TRUE. Attics often have a home’s biggest air leaks, which can increase your energy bill and make you uncomfortably hot in summer and cold in winter. Air seal and insulate your attic to improve your home's comfort and energy performance.


FALSE. Rinsing dirty dishes before loading your dishwasher wastes a lot of water and energy. Most dishwashers today can thoroughly clean dishes that have had food scraped, rather than rinsed off—the wash cycle and detergent take care of the rest. To make the most efficient use of your dishwasher's energy and water consumption, run the dishwasher only when enough dirty dishes have accumulated for a full load. Also, use the air-dry option if available.