This month we’re looking at strategies to save energy as well as save wear and tear on your computer. One of the most common questions I get is whether to shut down or simply “sleep” (or “hibernate”) your computer when it is not in use. You will hear many and varied opinions on this issue. Some say never shut down and others say always shut down. Many people formed these opinions years ago when computers used much more energy than they do today.

The easy answer is: If you use your computer every day, DO NOT shut it down, put in standby mode (more on this later).

If you won’t be using your computer for 2 or more days, you should shut it down. Some will argue that it should be shut down if your down time is more than 3 or 4 days. There is no clear answer here and it is not likely to be definitively answered soon. Since 98% of computer users work on their machines every day, the point becomes moot for most of us. And since it takes much less time to wake from standby mode than to power up, you save time as well.

Why?

Most personal computer equipment (and indeed most consumer electronics) have incorporated "Energy Star" power management standards (see this link). Devices that meet Energy Star standards save energy through special energy-efficient designs, which allow them to use less energy to perform regular tasks, and automatically enter a low-power mode when not in use. An average laptop computer uses around 2 watts of power in standby mode and a desktop about 5 watts. The EPA recommends setting computers to enter system standby (“sleep” on a Mac and “hibernate” on a PC) after 30 to 60 minutes of inactivity. To save even more, set monitors to enter sleep mode after 5 to 20 minutes of inactivity. The lower the setting, the more energy you save.

It may be tempting to ask “Why not shut down to save even more energy?” The reason is that when a device is power up, there is a strong surge of electricity sent through the circuitry. While this surge is much less in modern equipment than it was in older computers, it is often the main cause of hardware failure. Ever notice that an incandescent light bulb only burns out when it is turned on? Same principle. Also, the surge itself pulls substantial amounts of energy, often more than it might take to keep the computer on for several hours. An analogy would be the difference between city driving and highway driving. Leaving a computer on, but allowing it go into a low-power standby mode after 30 minutes, is the equivalent of efficient “highway driving.” The “stop-and-start” of city driving increases wear and tear.

Heat and Your Computer

The principle enemy of computer circuitry is heat. Heat in computers cannot be avoided because… well, E=MC², and those electrons are moving aren’t they? But it is important to provide an open, cool and/or ventilated space around your computer. For desktops, you should always consider where the internal fan blows its heat out and realize that if the vent is obstructed, the fan cannot ventilate the computer properly. Likewise, if your computer is in a small, enclosed area such as under a desk, the space around your computer’s intake AND output vents will remain warm. Early signs of poor ventilation can include frequent “freezing” (an oxymoronic term, but you get the drift).

For Laptops, it is equally important to provide proper ventilation. The best remedy is to buy a laptop base fan upon which your laptop sits in order to accomplish this. See this Google search for products of this nature.

How to Configure Standby Modes in Computers:

PC Users (Windows XP):

Right-click on the desktop and go to “Properties”

Click on the “Screen Saver” tab
   

Click on “Properties” at the bottom-right
   

Mac Users:

From the Apple Menu, choose “System Preferences”
   

Click on “Energy Saver”