Hello /sci/ I'm trying to settle a dispute, my friend has

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Laptop's circuitry fucks up, and the desktop automatically shuts itself

>>8255151
Provided it was well insulated, the laptop. It would heat the room up to 95 degrees at which point the room and laptop would be in thermal equilibrium, so there wouldn't be any further change in temperature.

>>8255155
total wattage.
Measure the current each PC draws and multiply it by your mains voltage. Average over a couple of hours with the same usage. Higher number gets the room hotter

>>8255164
>>8255165
This was essentially the dispute. I argued for thermal equilibrium, he argued for wattage and without any calculations we had to agree to disagree.
If someone could point me in the right direction I could do the math myself, it's just been a while since my thermo classes

>>8255151
Theoretically there is no limit to how much they could heat the room assuming there is no leak to the outside and the computers never stopped functioning. Heat is just energy and as long as there is an inflow of energy from the electrical current in the computers the total amount of inner kinetical energy in the air molecules (which is what we percieve as temperature) would increase. Energy can't disappear so as I said if the theoretical room doesn't leak any energy it would increase in temperature indefinetly.

>>8255172
Literally just measure the amount of power going into each device, the higher one will be heating the room faster.
The CPU temperature is pretty much a null point, it just gives you an impression as to how good their heatsink is rejecting heat to the environment, it doesn't set a maximum temperature the room could reach - once the room temperature rises, the heatsink temperature will rise due to the reduced rate of heat rejection from the heatsink.

>>8255183
The question isn't which will heat the room faster, it's how high each device theoretically could make the temperature go.

>>8255183
I disagree that the CPU temperature is a null point. As his device is a desktop PC it is more efficiently cooled (better heatsinks, fans, large empty container of air as well).
Which is also why I wanted to approach from the temperature side is so that I don't have calculate all these efficiencies.

>>8255183
>The CPU temperature is pretty much a null point, it just gives you an impression as to how good their heatsink is rejecting heat to the environment
But doesn't this tell you how fast the computer is heating the room? I get that OP asked which computer would heat the room to a hotter temperature but if you want to know which computer heats the room more quickly the temperature should matter. Even if the PC uses more energy, it's temperature is lower and therefore that extra energy must be stored as information in the computer rather than as heat in the room.

>>8255172
The way I'd go at answering it would be to treat the room as an isolated system and the computers as perfect black bodies with constant power output. Then the laptop will heat the room up to 95 degrees, while the computer will only ever heat the room up to 75 degrees. If you could heat the room to higher than 75, then you could create a cycle more efficient than a Carnot cycle. I don't really see why he would think that wattage had anything to do with the question.

>>8255197
The pc might be better at expelling the heat to the room instead of capsuling it in the chassi. Also there is probably a larger amount of air that is "sharing" the energy so the temperature doesn't rise as quickly as in the laptop and therefore there is more time to expell the hot air, thus reaching equilibrium at a lower temperature.

>>8255172
The energy required to cause a rise in temperature is calculated as [math]c*m*ΔT[/math] where c is a constant specific to a substance.

>>8255200
Assuming as you say that the room is an isolated system with no leak of energy outside of the room, where would the energy from the devices go after the point of 75 respectively 95 degrees go? If the room is isolated energy can not escape it i.e. it can not cool down.

>>8255200
>If you could heat the room to higher than 75, then you could create a cycle more efficient than a Carnot cycle.
Is that true? How is it possible then that the sun, with a surface temperature of 6000 K can heat the corona to a temperatures greater than 1000000 K?

>>8255211
>where would the energy from the devices go

Think of it as, at thermal equilibrium, heat from the room is flowing into the body at the same rate as heat from the body is flowing into the room.

>>8255215
The Coronal heat problem is an unsolved problem in physics.

>>8255216
Yea but there is still a constant increase in energy. The only difference is that after the point of 75 respectively 95 degrees it takes an extra effort to heat the computers themselves, thusly the increase rate in temperature would stagnate a bit but not come to a complete halt.

>>8255216
>at thermal equilibrium, heat from the room is flowing into the body at the same rate as heat from the body is flowing into the room.
Yes, the rate of heat flow is equal between the room and the computer, but this does not mean that the temperatures are equal.

>>8255221
It would come to a halt otherwise you could create a perpetual motion machine. Imagine using a certain power to heat the room, we'll say to 95 degrees like in the op, if your machine could heat a room to say 96 degrees then you could siphon off that extra heat as use it to power your radiator to heat the room some more.

>>8255223
Yes it does, it's literally the definition of thermal equilibrium.

>>8255228
Heat is just the internal kinetic energy of the molecules in the air. If we assume the room is isolated like you said, even after the point of 95 or 75 degrees there is still an influx of energy from the computers and no energy is making its way out of the room. Thusly the temperature would continue to rise as we otherwise would have to assume that energy just disappears and now we are breaking the laws of thermodynamics.

>>8255228
>Yes it does, it's literally the definition of thermal equilibrium.
Okay, but you're still misunderstanding. The temperatures of the computers were taken with the room at normal temperature. It's perfectly reasonable to say that as the temperature of the room increases, so does the temperature of the computer. At thermal equilibrium the rate of heat flows are equal and the temperatures are equal, but the temperature is not 95 degrees.
>It would come to a halt otherwise you could create a perpetual motion machine.
The only reason perpetual motion machines are impossible is because they require infinite energy. In this hypothetical situation, the computers are given a constant and unlimited energy source, so perpetual motion is not out of the picture here.

>>8255234
No, perpetual motion machines are impossible because they increase the amount of energy you put in to them. But the other thing you said is true, since energy can't disappear and we assume that the room is isolated and we have an infinite amount of energy coming into the computer, the temperature would rise indefinetly.

>>8255228
It would not be a perpetual motion machine as we are not creating energy from nothing. We are just pumping more and more nergy in to the room and thusly increasing the temperature indefinetly.

>>8255232
>>8255234
Please both of toy read the first entry here:
>http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/thereq.html

>>8255242
ok dude listen to me I will try to explain it simply. The reason the temperature does not go above 95 or 75 degrees or whatever is because the computer expells an equal amount of energy to the sorroundings as it is receiving from the electrical current. Increase the insulation of the chassi however and it will go above 95 or 75 degrees because less energy is being expelled into the sorroundings. It's the same reason the fucking water in a pot boils faster and the steam in the pot reaches a higher temperature when you put a lid on it.

You are suggesting that energy would simply disappear when you say the temperature can not go above which is an impossibility. Now I'm getting sick and tired of trying to explain this to you you fucking moron so shut up and try to use your brain.

>>8255242
>http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/thereq.html
The example in your link suggests that there is no additional influx of energy to the objects which is not the case in OP's example. In your link, we have a fixed amount of energy where as in OP's example the total amount of energy is constantly increasing.

>>8255242
>>8255254
And also, by the principle in your link the temperature would not rise to 75 and 95 degrees as the specific heat capacities of the air and the computer are different. It would be significantly lower when it reached equilibrium. You are wrong on all points.

>>8255242
>It is observed that a higher temperature object which is in contact with a lower temperature object will transfer heat to the lower temperature object.
>The objects will approach the same temperature, and in the absence of loss to other objects, they will then maintain a constant temperature.
This is only the case with two objects at constant temperature. The computer is not at a constant temperature because it has a power source. Let's assume the efficiency of the computer is the Carnot efficiency, and the room starts out at 60 degrees. The 95 degree computer then has an efficiency of 1-(60/95)=.368. Now awhile later the temperature of the room increases to 85 degrees. If we want the computers efficiency to be the same, .368 = 1-(80/T) where T is the new temperature of the computer. In this example, the computer went from 95 degrees to 126 degrees. I guess the answer to OP's question depends on whether you are keeping the efficiency of the computer constant or the temperature of the computer constant. In reality, both these values are changing significantly as the temperature of the room goes up.

>>8255261
But the fucking end result that the temperature increases indefinetly is unchanged. The heart of the issue is that this guy doesn't understand that the total amount of energy in the room is constantly increasing and that is causing the temperature to rise indefinetly.

My gaming PC runs less than 40 degrees C but still uses more power and generates more heat than your computers combined. Insufficient data.

>>8255165
/thread

OP is a dumbfuck who can't accept that he lost the argument. Why did this thread go another 30 posts?

>>8255195
>As his device is a desktop PC it is more efficiently cooled (better heatsinks, fans, large empty container of air as well).
none of that makes the heat go away magically. just do what other anons said, measure the energy input

the real question is, what kind of dumbfuck lets their PC run at 70C

>>8255267
The post you quoted is also wrong.
>>8255268
This anon gets it. The constant energy input would cause the temperature to rise indefinetly assuming the room is perfectly insulated. Jesus why is this so hard to understand?

>>8255252
Yeah you're right, I'm being a massive idiot here.
>Assume its isolated
>Except its getting a constant energy supply

Woops.

>>8255301
I meant insulated, my bad.

Also if you have problem with people assuming the best perfect scenario then you should not go into science. Literally no scientific formula considers outside factors.

>>8255304
>>8255301

And since OP didn't put any other parameters for his questions like loss of energy to the outside then it's only natural to assume the perfect scenario.

>>8255284
The post I quoted, and the post you quoted say the same thing you stupid fuck.

>>8255311
No because the post you quoted says a higher wattage would heat the room faster which is true but not relevant to OP's question.

tl,dr
Saw many retarded answers.
Temperature has nothing to do with it, just imagine a little incandescent bulb: it has a very high temperature, but can operate on a few watts of power, it would take forever to heat up the said room.
Now imagine simple electrical fan heater, it doesn't even glow, but that kilowatt or two can heat up the room quite readily.
High CPU temperature just shows how shitty and ridden with dust is computer's cooling system.

>>8255313
Trolling or stupid?

>>8255323
OP's question was which device would get the room hotter. That was the only parameter he put. Now if we consider the perfect scenario where we have an indefinite amount of time and a perfectly insulated room, the temperature would rise indefinetly. Eventually in both scenarios all of the universes energy would be concentrated to this theoretical room. The higher wattage device would accomplish this faster but the end result is the same.

>>8255151
The desktop pc.
Let's assume that both computers fail at the same temperature e.g. 200 degrees C.
When the room temperature is increased by the thermal power of the cpu, it also increases the temperature of the cpu, because the cooling air will be hotter.
And since the laptop runs hotter at the same room temperature, it will fail sooner, so the desktop pc is able to heat the room to a hotter temperature.

>>8255329
>Now if we consider the perfect scenario where we have an indefinite amount of time and a perfectly insulated room

Only a retard would make this assumption.

>>8255339
Just like only retard would create a scientific formula only valid in a vacuum, in other words the inside of your skull?

In a perfectly isolated, unmeltable room with limitless electrical power input, there is no reasonable upper limit to either. The desktop would achieve some desired temperature faster.

>>8255192

There is a significant lack of info to solve the problem. Other factors would be, mass of individual parts, conductance of heat of individual parts, insulation of your computers, how well your computers are cooled, etc...

Think of it this way, if we want to know the damage caused by a collision and all i say is that one object is moving at 20mph and another at 100 mph, then you can't solve it. It could be a pebble and a car respectively or vice versa, both of which have hugely different outcomes.

>>8255151
Most importantly you should not be running your computer that hot, laptop or desktop.

>95 degrees

>>8256714
That's not unusual for a laptop with load.

Bypassing basic science, the PC is probably heating the room more despite reading cooler. PC's don't have the same power consumption concerns as laptops and dissipate heat much better. The desktop's PSU is probably sucking down double or more what the laptop is.

Granted, the heat either is putting off is likely negligible when set against the pilot lights in your stove, and your own fat sweaty bodies.