Black Google would save $300k a year.

Sorry, but this is a load of crap.

Grade 9 science class will tell you that, surely.

Something that is designed to produce heat is going to be a hell of a lot more efficient than something that produces heat as a by-product of what it its actual intended purpose is.

You are partially correct, but in this instance a 100W monitor and a 100W heater will both produce the same amount of heat.
 
The visual light strikes the walls of the room and is absorbed as heat.

Heaters also emit light.

I'm not sure if its just me, but I dont remember the last time I huddled around my 17' CRT and tried to get warm.
 
Well, that really depends on your CRT...
 
You're mixing up "heat" with "energy".

No I'm not. A heater works by drawing current through a high resistance wire, giving off heat.

A monitor has a different purpose, but the net result is the same. If both devices have a power consumption of 100W, then both devices will emit exactly the same amount of heat.

If anybody disagrees, I would ask them to tell me in what form the energy used ends up as? I've already discounted light, as that is absorbed by materials and has a heating effect on those materials.
 
I'm not sure if its just me, but I dont remember the last time I huddled around my 17' CRT and tried to get warm.

Which demonstrates the futility of trying to save money by turning it off, especially if you have a heating system controlled thermostatically by air temperature. Of course when the house is too warm for the heating to be useful (ie summer), then you turn it off, thats common sense.
 
No I'm not. A heater works by drawing current through a high resistance wire, giving off heat.

A monitor has a different purpose, but the net result is the same. If both devices have a power consumption of 100W, then both devices will emit exactly the same amount of heat.

If anybody disagrees, I would ask them to tell me in what form the energy used ends up as? I've already discounted light, as that is absorbed by materials and has a heating effect on those materials.
I don't think you can just discount light like that, heat and light are different things.

Also what about the kinetic energy used by the fan in the monitor?
 
Yes, they're different things. But what do you think happens to the energy in light when it is absorbed by another material?

Regarding the fan, all that does is push air around. The movement of air molecules releases energy in the form of heat.

All very simple stuff. Its just transfer of energy.
 
Yes, they're different things. But what do you think happens to the energy in light when it is absorbed by another material?
It's heated up, but nowhere near as much as direct thermal conduction.
Regarding the fan, all that does is push air around. The movement of air releases energy in the form of heat.

All very simple stuff.
Yes but kinetic energy is used up . Some of the energy going into the fan is wasted as heat, but a lot of it is transfered into kinetic energy . You're right, this is simple stuff. What physics qualifications are you studying? Might want to change to something else ;)
 
It's heated up, but nowhere near as much as direct thermal conduction.

That is because the levels of energy involved are completely different. Otherwise you would get a suntan every time you sat at your monitor. Most of the power output of a desktop monitor ends up as heat. A very small percentage ends up as light, which is absorbed by the materials it reaches, and converted to heat. If the light output from a monitor is equivalent to 1 watt of power, then you could hardly expect that to compare to a 100W heater now could you?

A monitor in this respect is not very different than an incandescent light bulb. Put a 1KW heater in a room, and then put 10x100W lightbulbs next to it, and both will produce almost exactly the same heating effect.

Yes but kinetic energy is used up . Some of the energy going into the fan is wasted as heat, but a lot of it is transfered into kinetic energy . You're right, this is simple stuff. What physics qualifications are you studying? Might want to change to something else ;)

Energy is never used up. It is merely converted into other forms. In this instance, all the energy involved is converted into heat.

Honestly, its not hard to grasp.
 
Energy is never used up. It is merely converted into other forms. In this instance, all the energy involved is converted into heat.

Honestly, its not hard to grasp.
Yes, kinetic energy to move the particles around, how does that turn into heat..
 
The visual light strikes the walls of the room and is absorbed as heat.

If you've got perfectly black walls maybe that's true to some extent. And remember the temperature of your room is determined by air temperature, not the wall temperature.

However, in the imperfect world, heaters are more "efficient" at heating the air of the room than monitors, as the light from monitors is scattered and lost out of your windows.

Also, a black google would save energy (with an efficiently designed monitor anyway), because the monitor would only draw the power needed to produce an image. If the screen is mostly black, it doesn't have to draw much power.
 
But George Bush doesn't care about black people so we'll have to wait till 08.
 
If you've got perfectly black walls maybe that's true to some extent. And remember the temperature of your room is determined by air temperature, not the wall temperature.

The temperature of the walls and of the air are very much related, and quite important to one-another. This is why people line their lofts with insulation.

However, in the imperfect world, heaters are more "efficient" at heating the air of the room than monitors, as the light from monitors is scattered and lost out of your windows.

I have already made mention of this, however the amount of energy lost in this respect is minimal. Most of the energy used ends up floating up from the back of the monitor in the form of heat. Also, windows usually form a very small surface area of the total surface area of the walls, ceiling, and floors of the room.

Also, a black google would save energy (with an efficiently designed monitor anyway), because the monitor would only draw the power needed to produce an image. If the screen is mostly black, it doesn't have to draw much power.

For a flat panel display I believe it makes no real difference as the level of backlighting is constant? But it would still make no real difference to a home with central heating controlled by air temperature thermostat as the central heating would be on for less time proportionate to the amount of heat emitted from the monitor (although small, it is actually measureable).
 
I'd never think such argument would form on these forums.
 
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