CRT Monitors

Cathode ray tube (CRT) monitors are the standard displays used in desktop computer systems.

In the average desktop computer system, 60% of the energy consumption is due to the cathode ray tube (CRT) monitor. The normal power requirements of 15” to 21” CRT monitors typically fall between 65 W and 120 W. However, like television sets, the energy consumption of CRT computer monitors can vary widely among different models, even units of the same screen size. An average 17" CRT monitor consumes 85 W during typical usage (Ref). Black and white monitors consume less power than color monitors. See the ICT Power Consumption Reference Tables for additional details.

CRT monitors that qualify for Energy Star designation are required to power down to 15 W or less after 15 to 30 minutes of inactivity and down to 8 W after 70 minutes of activity . Some monitors continue to consume 5-8 W of power after they have been shut down. In this case it is a good idea to make sure that the monitors have been turned off by hard switch or unplugged completely at night to avoid wasting electricity. On some monitors, there is a small LED light on or near the on/off switch that lights up to indicate activity. If the LED is lit or flashing, the monitor is still drawing some amount of power.

CRT monitors require a burst of energy upon startup equivalent to 2-5 times normal operating power consumption. For very small energy systems, it is advisable to test the inverter of your energy system to make sure it can power up the CRT monitor reliably and consistently, particularly for the larger monitors.

Related Web-based Resources

• Understanding CRT Monitors (Short article)
• CRT vs. LCD (Short article)

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