Personal Computers
We hear about it every night on the news: the world is in an energy crisis; greenhouse gas emissions are on the rise, global warming s a serious problem. Youve tried to be a part of a solution by recycling, carpooling when possible, and or walking or riding a bike. But have you ever thought about your computer? Just by changing a few simple actions, you can help improve energy management, increase energy efficiency, and reduce waste.
Personal computers and other office equipment consume a significant amount of energy. We can all do our part to help reduce the energy consumption on the campus and thereby reducing our energy bills. Below are some guidelines that can significantly reduce the Delta State Universitys energy bill as well as conserve critical resources.
Does it harm the PC to turn it off?
Older computers did not have the ability to self-park hard drives and the recommendation was to leave them on all the times so that there was less wear and tear on the hardware. Todays computers are designed to take advantage of self-parking drives and more efficient power management. Turning off computers does not shorten their lifetime.
Is there a significant savings potential?
The average desktop computer and monitor consume .12 KWH per hour. Turning the computer off at night and on the weekends could result in a significant cost savings for Delta State.
The following is a list of suggestions that you can use to reduce the energy usage of your personal computer.
Q: Is it more energy efficient to keep turning fluorescent lighting on and off all day or to just leave it on? Our office uses the room at least every 20 minutes during an 8-hour work day but no one is ever in there all day.
A: By leaving fluorescent lamps on you save the lamp life, but not energy costs.
Its a tradeoff between buying new fluorescent lamps which are generally pretty cheap and the cost of electricity to run the lamps all day for 20 minutes of actual use. This depends on your cost of electricity. Basically, weve found it more energy efficient to turn lights off when not in use. (For that type of room it might be cost effective to install an occupancy sensor unless people actually turn the lights off when they leave.)
Q: Is it more energy-efficient to let a lightbulb burn for a short period of time, or to turn it off and then on again? I read once that the surge in power when a bulb is turned on is equal to letting the bulb burn for a while?
A: It is more energy efficient to turn the light off than to leave it on. Energy is measured with respect to time. The unit used to measure electrical energy is the kilowatt-hour or thousand-watt-hour, the amount of power or watts that you use in one hour. The momentary or millisecond or less surge of electricity required to start your light bulb will not impact your energy cost, but leaving it on all the time will. With the rising cost of energy, its probably a good idea to turn the lights out when you are not using it.
(Not to mention the pollution impact, less energy use, less emissions from power plants.)
Turning the lights on and off a lot will impact your lamp life, however. If you compare the number of bulb(s) you need to buy versus the cost to let the light burn all the time, it will still probably be cheaper to turn the lights off.
Q: How do I check to see if my computer equipment has an Energy Star feature? (Some computers, like mine, were built by someone and they dont have the Energy Star logo on them.)
A: It will usually be necessary to make a few changes to the computers BIOS (Basic Input Output Options) before changing the operating system settings. Making these changes is typically quite simple, but because there are many different systems in use today, it is impossible for us to give you detailed instructions on every BIOS. Check the documentation that came with your computer or the manufacturers or distributors website.
A critical part of power management is the major system timersthese are typically called doze, standby (or sleep), and suspend, and occur in that order.
Doze reduces power during periods of inactivity by lowering processor (CPU) speed and powering down unused logic and memory.
Standby usually sends a signal to power down the monitor, but may also slow down the whole system (in a BIOS without a Doze mode).
Suspend typically sends the command to go to the lowest power operation by sending the off signal to the monitor and CPU and cutting system board power [Source: EPAs Energy Star website]
Q: Yesterday I had a 7:30 pm meeting in the College of Education building, and two different thermometers registered 80 degrees! Why is it necessary for the heat to be on so high during the evening hours?
A: In order to conserve energy, many buildings utilize what is called a temperature setback. This is a process through which building air handling units are automatically scheduled based on occupancy patterns. In a building that is typically empty during nighttime hours, air handling units are shut down so as not to waste energy by heating or cooling spaces while it is unoccupied. In these situations, a particular space will only receive heating or cooling in extreme temperature cases. If your schedule requires you to spend extended periods of time in a building during its setback period, you may want to speak to your building facility manager to request an override or building schedule modification.
Temperature setback is the probable explanation if you experienced this during the summer months. However, if this situation occurs in the winter, it may be an indication of equipment failure and you should notify the Plant Department.
Q: Recently, the fluorescent bulbs in our office were replaced, but the plastic panels covering them were left off. I sit directly under this light at a computer 8 hrs a day. I heard that plastic stops the UV rays coming through and without it, a person is exposed to these rays unnecessarily. From a health and safety point of view, is there a real risk here?
A: Ultraviolet content emitted from the energy-efficient T8 fluorescent lamps used at U-M is very low. The amount of UV produced by standard fluorescent lamps is not hazardous and does not pose a major health concern. In fact, a paper by the National Electrical Manufacturers Association (NEMA) explores this subject in more detail. It cites a study in which it was determined that UV exposure from sitting indoors under fluorescent lights at typical office light levels for an eight hour workday is equivalent to just over a minute of exposure to the sun in Washington, D.C. on a clear day in July [Source: GE Lighting, NEMA]. For more, see the Permissible Exposure Time PDF in the Energy Conservation Tools section.