Energy Savings

Well my personal computer graphics card idles at about 58 degrees (I think its something like about 50W losses or more just for the graphics card with the monitor off). We have two similar systems in a small room along with two clothes drying racks. They dry surprisingly fast.

Even with your average (lower spec) commercial computer you are better off turning them off overnight in most circumstances.

Just finished a survey in my own office using this:

http://www.dse.co.nz/cgi-bin/dse.filereader?485575a8007a05f82741c0a87f3b06c0+EN/catalogs/CTG0000181

A standard desktop computer = 90 to 130 watts

Laptop = 65 watts

Flat screen monitor = 65 watts

Server can be 200 to 300 watts

ALL the energy is disipated as heat.

Biggest surprise; both monitor and computer take 11 watts each WHEN SWITCHED OFF. This is because "OFF" buttons are OFF no longer, but are soft swicthes that merely put the computer into standby. Power is still used by the losses incurred by the power supplies.

Note that YOU put out about 300W of heat, considerably more than most current computers, especially laptops.

No, the human body puts out about 100W. Sandia Labs has a room controlled to 0.1 deg. C. When a person goes into that room, they turn off a 100W light bulb to compensate.

You may well be right... I don't remember where or when I got the 300W figure, nor what kind of activity the 300W person was doing...

On the other hand, clearly there will be variation from person to person, depending on size, skin temperature, breathing rate, clothing, etc. and a large variation depending on what the person is doing physically and/or mentally. I suspect that both of our values are well within the range of variation; The 100W is probably high for a bedridden elderly person, and the 300W is probably low for a large athlete running on a treadmill.

I would be interested in knowing a little more about it. I get tired doing mental work, although it is a different kind of tired from the result of physical work - do I put out more heat when I'm thinking hard?

Dick

dkwarner

300Watts spot on the nose for a live body!

aqua_doc

it sure will get a little warm overnight it does depend upon what you have on overnight!

My situation (Sleepy)

I have my PC running, doing an ovenight scan, usually AV, it then goes into a hibernation mode - this takes around 15 Watts I believe.

I switch off the monitor overnight, so this has to be switched on in the morning to understand the results of the scan. I do not switch off the printer, or the scanner, the next scanner ( this one has just died after 5 years) will be USB powered, so less power and will go off with the Desktop PC. The laptop is off or in Hibernation overnight. The speakers are on overnight - probably 1 watt max, again not measured. Router and Backup hard disc are on continuously. Fairly low power. UPS remains on and I do not not know the standby power for this - must check!

Other Power sources include Mobile and PDA chargers, which by their nature remain on but again are relatively low power. All lights apart from LEDs are off overnight.

Obviously I could do a little better - I do not want to lose the overnight scan as this can pick up all sorts of minor problems which could become major.

I have always wanted a simple power measuring device which I could put between a load and the supply to understand various power loads.

I will be doing what I can to reduce this but I do not want to spend a period each night switching off and a similar amount of time in the morning switching on. I suppose that a rejig of the distribution system could take off a lot of these things with one hit - must be careful to leave some items on separate lines.

An indication of the amount or power that each item consumes when active; hibernation, off would be useful. I need UK values as things like switching mode PSUs are different either side of the pond???

Sleepy

Energy Savings 06/18/2008 1:07 PM

I have recently been surprised to feel the difference in temperature in my computer room (when I leave the door closed) from the rest of the rooms in my house. The room is fairly large and the temperature is obviously several degrees warmer. I tend to leave the computer on in a minimal state continuously. The heat is obviously generated by the computer and transferred to the room by the fan. It got me thinking about the years I have been doing this and the general situation in the offices where I have been employed in the past, where leaving the computers on overnight was the norm. Seems that this results in a fairly large amount of heat generation, energy consumption and the need for additional AC in the summertime. Worldwide, this is likely a significant consumer of electricity we didn't have 30 years ago. Does anyone have any numbers on the wasted power from this source and how much it amounts to percentage-wise? Shutting the computer down when not in use seems like an easy way to reduce power consumption and costs; of course, we are as a culture so much into instant access that it results in a loss of our "precious time". I know I am going to take action for my own part. Start with a spread sheet!! Sleepy

Some form of auto computer startup would be a help to circumvent the desire to have a computer up and ready when needed but shutoff when not needed.

That has been a standard feature of the 'Energy Saver' on Macs for many years. I don't know about other brands of PCs, but I doubt if it is unique to Macs...