Your Area of Interest:
None Apply

Log Out |

Source: http://www.sxc.hu/

You may be surprised to learn that electronic office equipment has emerged as the fastest-growing energy user in commercial buildings. In fact, office equipment makes up approximately 7% of all commercial sector power consumption, accounting for $1.8 billion per year in total energy costs. Taking steps to reduce energy consumption in the office not only reduces energy bills, it reduces the impact of harmful emissions on the environment as well.

The Energy Cost of Office Equipment

The following table illustrates typical office equipment energy use and its projected annual energy cost.

Device	Typical Operating Power(Watts)	Typical Idle Power (Watts)	Typical Sleep Power (Watts)	Annual Energy Cost
				8 Hours/Day, 5 Days/Week, Sleep Mode*	24 Hours/Day,  7 Days/Week, Sleep Mode**	24 Hours/Day,  7 Days/Week, No Sleep Mode**
Desktop Computer	100	60	6	$12	$16	$56
CRT Monitor	60	40	4	$7.70	$10	$37
LCD Monitor	35	8	2	$2.50	$3.90	$9.20
Laptop	65	15	1	$4.60	$5.30	$15
Laser Printer	350	85	20	$26	$29	$77
Fax Machine	300	75	10	$12	$19	$69
Copier (large)	1,400	350	40	$55	$82	$315
* Assumes $0.10/kWh, 2085 operating hours per year, 20% full power, 60% overall idle mode, 20% sleep mode for computers and monitors, 50% idle mode, and 45% sleep mode for printers, faxes, and copiers. Equipment is turned off for 6675 hours. ** Assumes $0.10/kWh, 8760 operating hours per year, same 8-hour/5-day mode and either sleep or idle for non-work hours (work day nights and weekends). Equipment is never turned off. Sources: Manufacturers' specifications, ENERGY STAR, and Lawrence Berkeley National Laboratory

You Need All the Sleep You Can Get

From the above table, it is clear that sleep mode power consumption and the mechanism for placing office equipment into sleep mode are very important. Fax machines and copiers typically operate less than 5% of the time, and even if the computer screen is active 90% of the 40-hour work week, PCs are still sleeping 80% of the time overall, when compared to 24/7 hours of operation.

The following table shows a selection of common printers and the ENERGY STAR recommended energy use for each type.

ENERGY STAR Recommended Sleep Mode Power
Printer Speed	Laser B/W and Ink Jet	Laser Color
>10 pages/min.	10 watts or less	35 watts or less
11-20 pages/min.	20 watts or less	45 watts or less
21-30 pages/min.	30 watts or less	70 watts or less
Source: Federal Energy Management Program

Computers and Laptops. A typical desktop computer will consume somewhere in the range of 100 watts in active use, plus another 60 to 75 watts for a CRT monitor, depending on its size and vintage. During sleep mode, the PC will consume 5 to 8 watts and the monitor will consume 3 to 6 watts in more efficient models. As expected, different designs are more energy efficient, with a 17" LCD monitor typically rated at 35 watts, compared to a 17" CRT at 80 watts for operating mode energy use. Accessories, such as speakers, can add another 30 to 40 watts. Laptop computers use less energy than desktops because they are smaller and have LCD displays. They can generally be found in the 45- to 85-watt range, but can be over 90 watts with graphics cards.

Copiers. Copiers are the most energy-intensive of all office equipment because they need to be kept warm so the toner will fuse to the paper. Copiers go into low-power mode after they have not been in use for 15 minutes, and they have an off mode, which consumes 5 to 20 watts of energy—typically after two hours of inactivity. These low- and off-power modes enable energy savings of 40% to 50%, compared to standard models.

Printers and Scanners. Printers and scanners are large energy consumers in the office landscape. A typical color laser jet printer will consume 15 to 20 watts in standby and 350 to 400 watts in print mode, while larger printers may consume up to 1,000 watts (1 kilowatt) or more. The user will find quite a range of energy consumption for all manufacturers, depending on size, print quality, speed, color capability, and so on. Sleep or standby modes are essential to reduce energy use (sometimes by more than 60%). In the sleep mode, printers and scanners typically consume 5 to 10 watts for standard models, but consume as much as 25 to 30 watts for wider-width color printers.

Fax Machines. The typical office fax machine that is left on continuously, day and night, is estimated by the U.S. Department of Energy (DOE) to be in active sending or receiving mode 270 hours per year (3% of the time). Once again, the sleep mode becomes a critical issue. By powering down, fax machines can reduce energy costs nearly 40%. The most efficient fax machines consume 3 to 20 watts in sleep mode, with the greater energy users occupied by the color fax machines at higher transmission speeds.

Make Your Office an ENERGY STAR

When purchasing or replacing computers or other office equipment, be sure to choose products that are ENERGY STAR rated. ENERGY STAR is a U.S. Department of Energy program that encourages the use of energy-efficient products and practices. ENERGY STAR certification means that office products have the highest energy performance.