No Title 2248
Switch it off, or leave it on?
Eco consumer: From fridge to TV
Dollars & Sense: Facts and myths of energy use
Switch it off, or leave it on?
Tips for saving energy when you leave the room
When do you burn less electricity by leaving a device on than by turning it off?
It depends.
For computers and lighting, the answers seem pretty clear-cut.
The federal Energy Star program says turn your computer off at night. Microsoft.com says you conserve nearly as much energy if you set it to “hibernate.”
The U.S. Energy Department recommends turning off the monitor if you won’t use your PC for at least 20 minutes, and turning off the PC if you won’t use it for more than 2 hours.
With lighting, the answer to “on or off?” depends on the type of lights. Turn incandescent bulbs off whenever you don’t need the light. They’re inexpensive to replace but waste energy when left on.
Fluorescent lights cost more than incandescent, and burn out faster if turned off and on frequently. In general, turn off fluorescents if you won’t need them for at least 15 minutes.
Eco consumer: From fridge to TV
Would you like to make minimal energy demands on your fridge and TV as you fortify yourself with a pastrami sandwich before settling in for your weekly CSI fix?
On the Yahoo! Answers Web site, a broadcast engineer advises that you turn the TV “on and off as needed.” Another expert, with more than 25 years’ experience servicing TV sets, says turning them on too frequently “kills parts.”
Whether you should shut the refrigerator door between the pastrami and the mayo, according to one posting on Answerbag.com, depends on the surrounding thermodynamics. If nearby movement is creating convectional crosscurrents, shut the door. Otherwise, don’t.
Dollars & Sense: Facts and myths of energy use
A computer uses 130 watts while on, 15 in standby. Here are some consumer “myths” regarding computers’ energy use:
- Turning your PC off uses more energy than leaving it on. False.
- Turning your PC on and off wears it out. False. PCs are designed to handle 40,000 on/off cycles, more than are likely to occur during your computer’s lifetime.
- Screen savers save energy. False. A screen saver may burn more energy than doing without one.
- Your computer uses zero energy when “off.” True for monitors but false for computers unless they’re unplugged. A plugged-in PC burns at least 2 watts to maintain connectivity.
Planetgreen.discovery.com offers this list of other household gadgets that are often left on unnecessarily, and the wattages they consume per hour:
- TV–100 watts while on, 10 watts in standby
- DVD player–12 watts on, 7 in standby
- Modem–14 watts whether you’re using it or not
- Laptop–29 watts in use, 2 in standby
- Phone charger–5 watts in use, 1 in standby
- Ceiling fan–.1 kilowatt-hour
- Space heater–.09 kilowatt-hour
