Does a pc consuming 500 watts from wall, heat a room similar to 500 watts hair dryer?

[300DaysToGTA6]

Does a pc consuming 500 watts from wall, heat a room similar to 500 watts hair dryer?

[ChrisLoudon]

1 minute ago, BigLion said:

Does a pc consuming 500 watts from wall, heat a room similar to 500 watts hair dryer?

Theoretically, yes.

 

The difference between the PC and the Hair Dryer is the Hair Dryer is pumping that heat into the room in a more direct and instantaneous manner.

 

The PC is doing it more slowly as heat moves from the IHS > Heat Sink > Inside Case > Case > Desk > Cavity........ 

[Gorgon]

 

[RevGAM]

17 minutes ago, BigLion said:

Does a pc consuming 500 watts from wall, heat a room similar to 500 watts hair dryer?

Not exactly, because some of the electricity doesn't produce heat, like an incandescent light bulb. Yet, like that bulb, most of it ends up becoming heat as Chris explained. 

[Applefreak]

27 minutes ago, BigLion said:

Does a pc consuming 500 watts from wall, heat a room similar to 500 watts hair dryer?

Short answer, no. While both may consume the same amount of electricity they work differently. A hair dryer is creating a resistance by forcing current over a thin grid which then heats up and would melt if the fan inside weren't there to move air across. A pc is comprised of many thousand components that use the same amount of electricity in different ways. Each component then is rated for energy loss and energy lost to heat. If you were to add them up, you wouldn't come close to the amount of heat a hair dryer will put out. 

 

As far as heating your room with your computer: Assuming your pc sits inside a small enough bedroom, you will actually notice it getting warmer over time. Having a top mounted radiator in your case will be more efficient as heat transfers more efficiently into the atmosphere. It will also radiate more heat after the system has been shut down. That being said, you can't rely on such a solution to properly warm up a room in winter time alone. Same goes for a 500W hair dryer or space heater, those are not powerful as well.

[Agall]

25 minutes ago, BigLion said:

Does a pc consuming 500 watts from wall, heat a room similar to 500 watts hair dryer?

Most of the energy into a computer is converted into heat waste but not all of it. In both devices, some of that energy is converted into mechanical energy to move the air as well.

 

If you eliminate a lot of the variables, example being how most PCs disperse heat more homogenously around them versus the beam design of a hair dryer, then practically the answer is yes.

 

If we consider other variables, that gets into the discussion of heat flux, which its heat transfer per second per square area, where a hair dryer is more likely to have a higher heat flux than a computer based on its design. The volume of the affected space being proportional to how much a given amount of energy raises the temperature of the space. Temperature being the average random molecular kinetic energy of a substance.

[Kilrah]

Yes. The amount of the consumed energy that does not end up as heat locally in a PC is infinitesimal, essentially just the almost nothing needed to record state changes in storage media and what gets transmitted as e.g. network communications (wired or wireless) that go beyond the room. 

 

At room scale 500W is 500W regardless of the way it's dispersed.

[SorryBella]

1 minute ago, Kilrah said:

At room scale 500W is 500W regardless of the way it's dispersed.

Its just the form would be different, or how it feel on your body. Energy cannot be created, nor destroyed.

[Brooksie359]

7 minutes ago, Applefreak said:

Short answer, no. While both may consume the same amount of electricity they work differently. A hair dryer is creating a resistance by forcing current over a thin grid which then heats up and would melt if the fan inside weren't there to move air across. A pc is comprised of many thousand components that use the same amount of electricity in different ways. Each component then is rated for energy loss and energy lost to heat. If you were to add them up, you wouldn't come close to the amount of heat a hair dryer will put out. 

 

As far as heating your room with your computer: Assuming your pc sits inside a small enough bedroom, you will actually notice it getting warmer over time. Having a top mounted radiator in your case will be more efficient as heat transfers more efficiently into the atmosphere. It will also radiate more heat after the system has been shut down. That being said, you can't rely on such a solution to properly warm up a room in winter time alone. Same goes for a 500W hair dryer or space heater, those are not powerful as well.

I mean the issue is that because of conservation of energy most of it ends up as heat eventually. The only thing I can think of that wouldn't be heat is sound and even then at some point sound would transform into a different type of energy. Same with light as that ends up as heat as well. I feel like people like to overcomplicate things when you can basically take it as 500 watts of heat and as someone who does hvac design in buildings you would do exactly that if it was assumed it would run at that in the worst case scenario. Granted that would be worst case and generally you wouldn't expect it to run at max capacity all the time anyways but you always want to engineering for the worst case scenario that way you don't have stuff break when that situation happens. 

[Brooksie359]

10 minutes ago, Agall said:

Most of the energy into a computer is converted into heat waste but not all of it. In both devices, some of that energy is converted into mechanical energy to move the air as well.

 

If you eliminate a lot of the variables, example being how most PCs disperse heat more homogenously around them versus the beam design of a hair dryer, then practically the answer is yes.

 

If we consider other variables, that gets into the discussion of heat flux, which its heat transfer per second per square area, where a hair dryer is more likely to have a higher heat flux than a computer based on its design. The volume of the affected space being proportional to how much a given amount of energy raises the temperature of the space. Temperature being the average random molecular kinetic energy of a substance.

Again I think people like to overthink things. Yeah lights produce light and heat but you can basically assume that all of the watts of a light are turned into heat eventually and that is what you do for hvac design. Funny enough one of the biggest producers of heat is actually people's body. You would be surprised what a crowd of people can produce in watts of heat lol. 

[Applefreak]

1 minute ago, Brooksie359 said:

I mean the issue is that because of conservation of energy most of it ends up as heat eventually. The only thing I can think of that wouldn't be heat is sound and even then at some point sound would transform into a different type of energy. Same with light as that ends up as heat as well. I feel like people like to overcomplicate things when you can basically take it as 500 watts of heat and as someone who does hvac design in buildings you would do exactly that if it was assumed it would run at that in the worst case scenario. Granted that would be worst case and generally you wouldn't expect it to run at max capacity all the time anyways but you always want to engineering for the worst case scenario that way you don't have stuff break when that situation happens. 

Well there are are components witch will turn the energy into light, others for example will turn a generator, which in turn creates energy (HDD, fans), others like on SSDs. A lot will create magnetic fields. The same energy goes in but not all is heat that comes out. Yes, for the most part you are correct. There will be a lot of heat dissipated over time as well.

[Agall]

5 minutes ago, Kilrah said:

Yes. The amount of the consumed energy that does not end up as heat locally in a PC is infinitesimal, essentially just the almost nothing needed to record state changes in storage media and what gets transmitted as e.g. network communications (wired or wireless) that go beyond the room. 

 

At room scale 500W is 500W regardless of the way it's dispersed.

If the hair dryer was pointed towards the door and therefore out of the room, it would impact the way its dispersed into the space and therefore how that energy affects the temperature of the room. Versus a PC in the farthest corner from the most effective heatsink for the space.

 

The answer is yes practically speaking, but it depends on the variables.

[Agall]

2 minutes ago, Brooksie359 said:

Again I think people like to overthink things. Yeah lights produce light and heat but you can basically assume that all of the watts of a light are turned into heat eventually and that is what you do for hvac design. Funny enough one of the biggest producers of heat is actually people's body. You would be surprised what a crowd of people can produce in watts of heat lol. 

Yes, a human would eventually overheat and die if the surrounding space wasn't a perpetual heatsink. Really hot spaces are not fun, especially if you've ever been in an enclosed space on fire intentionally where the air inside your SCBA mask is so hot that it's burning your face.

 

I'm not overthinking things, this post is however. Mostly designed to dispel the myth in the title, but I get all nerdy into thermodynamics to properly explain why.

 

[Brooksie359]

10 minutes ago, Applefreak said:

Well there are are components witch will turn the energy into light, others for example will turn a generator, which in turn creates energy (HDD, fans), others like on SSDs. A lot will create magnetic fields. The same energy goes in but not all is heat that comes out. Yes, for the most part you are correct. There will be a lot of heat dissipated over time as well.

Again you can basically assume that all that energy will eventually turn into heat when enclosed in a room. Sure you can try and account for all the different types of energy but the fact of the matter is you are basically going to get 500 watts of heat in your room regardless of how that heat is produced and where in the room. 

[PCGamer2727]

In a real world scenario, one difference is that the PC probably doesn't pull a consistent 500W but the hair dryer does.

[Agall]

1 minute ago, Brooksie359 said:

Again you can basically assume that all that energy will eventually turn into heat when enclosed in a room. Sure you can try and account for all the different types of energy but the fact of the matter is you are basically going to get 500 watts of heat in your room regardless of how that heat is produced and where in the room. 

Rooms aren't enclosed, otherwise there'd be a larger problem of oxygen partial pressure to keep the hooman alive. Unless we're talking submarines or spaceships with CO2 scrubbers, any space has its own heatsink(s), like the heat capacity of the air in the neighboring spaces.

 

How that heat is dispersed is important since none of these spaces are closed systems. With all other variables removed (mind you that are important to a proper answer) then yes, 500W of continuous power consumption from a hair dryer or PC has to go somewhere, otherwise the device would eventually melt.

 

15 minutes ago, Agall said:

If the hair dryer was pointed towards the door and therefore out of the room, it would impact the way its dispersed into the space and therefore how that energy affects the temperature of the room. Versus a PC in the farthest corner from the most effective heatsink for the space.

 

The answer is yes practically speaking, but it depends on the variables.

 

[Kilrah]

24 minutes ago, Agall said:

If the hair dryer was pointed towards the door and therefore out of the room

 

5 minutes ago, Agall said:

Rooms aren't enclosed, otherwise there'd be a larger problem of oxygen partial pressure to keep the hooman alive. Unless we're talking submarines or spaceships with CO2 scrubbers, any space has its own heatsink(s), like the heat capacity of the air in the neighboring spaces.

 

That's completely out of scope. When OP asks about 2 500W heat sources in a room they're not supposing "one is pointed towards the outside of the room and the other isn't" or "the room leaks heat in a different way in both cases".

 

[Brooksie359]

1 minute ago, Agall said:

Rooms aren't enclosed, otherwise there'd be a larger problem of oxygen partial pressure to keep the hooman alive. Unless we're talking submarines or spaceships with CO2 scrubbers, any space has its own heatsink(s), like the heat capacity of the air in the neighboring spaces.

 

How that heat is dispersed is important since none of these spaces are closed systems. With all other variables removed (mind you that are important to a proper answer) then yes, 500W of continuous power consumption from a hair dryer or PC has to go somewhere, otherwise the device would eventually melt.

 

 

You are way overthinking things. I am not saying that no heat is transferred outside of the room. Obviously there is for obvious reasons but you would still treat 500 watts of heat for a 500 watts of power in a room. Now how that heat gets transferred afterwards is not important to the question of does 500 watts of a computer go to heat. Also assuming your are designing hvac systems with that heat in mind the temperature of the room the heat is being produced will be the same as the one in the next room if designed correctly because they should both be cooled to whatever the system was designed to cool to. I mean if you designed them to cool to 75 degrees both that room and the room next to it should be at 75 degrees and thus no heat should be transferred between the two. 

[Agall]

6 minutes ago, Kilrah said:

 

 

That's completely out of scope. When OP asks about 2 500W heat sources in a room they're not supposing "one is pointed towards the outside of the room and the other isn't" or "the room leaks heat in a different way in both cases".

 

 

40 minutes ago, Kilrah said:

 

At room scale 500W is 500W regardless of the way it's dispersed.

I was simply disagreeing with this statement, as a way of demonstrating that how its dispersed does matter. I'm even excluding energy that can penetrate walls like electromagnetic radiation and keeping it within scope. 500W of radio waves will have a substantial amount of its energy leave the room, only some being attenuated by the matter between it. In the case of thermal energy however, how it enters the space and at what heat flux does matter.

[Brooksie359]

19 minutes ago, Agall said:

 

I was simply disagreeing with this statement, as a way of demonstrating that how its dispersed does matter. I'm even excluding energy that can penetrate walls like electromagnetic radiation and keeping it within scope. 500W of radio waves will have a substantial amount of its energy leave the room, only some being attenuated by the matter between it. In the case of thermal energy however, how it enters the space and at what heat flux does matter.

We are talking about a computer so the amount of energy going to electromagnetic waves that arent captured in the room are minimal. 500w of heat is 500w of heat and will heat the room like 500w of heat will. Sure you might have a slightly different temperature distribution in the room but again heat does try to dispurse and the temperature rise of the room over time will be similar. Again I feel like as someone who designs hvac systems for a living you are way overcomplicating things. 

[Agall]

29 minutes ago, Brooksie359 said:

You are way overthinking things. I am not saying that no heat is transferred outside of the room. Obviously there is for obvious reasons but you would still treat 500 watts of heat for a 500 watts of power in a room. Now how that heat gets transferred afterwards is not important to the question of does 500 watts of a computer go to heat. Also assuming your are designing hvac systems with that heat in mind the temperature of the room the heat is being produced will be the same as the one in the next room if designed correctly because they should both be cooled to whatever the system was designed to cool to. I mean if you designed them to cool to 75 degrees both that room and the room next to it should be at 75 degrees and thus no heat should be transferred between the two. 

Yes, heat transfer does not occur between two materials of the same temperature.

 

My first post I simply answer the question, I only go deeper down the rabbit hole because I like to be precise and try to refrain from generalized absolutes that can be technically incorrect, even if its better for mass understanding. When I do, I like to make caveats to properly discuss why. Its why I say 'practically speaking' and eliminate some variables that reside in the minority regarding contribution.

1 hour ago, Agall said:

Most of the energy into a computer is converted into heat waste but not all of it. In both devices, some of that energy is converted into mechanical energy to move the air as well.

 

If you eliminate a lot of the variables, example being how most PCs disperse heat more homogenously around them versus the beam design of a hair dryer, then practically the answer is yes.

 

If we consider other variables, that gets into the discussion of heat flux, which its heat transfer per second per square area, where a hair dryer is more likely to have a higher heat flux than a computer based on its design. The volume of the affected space being proportional to how much a given amount of energy raises the temperature of the space. Temperature being the average random molecular kinetic energy of a substance.

 

[Agall]

16 minutes ago, Brooksie359 said:

We are talking about a computer so the amount of energy going to electromagnetic waves that arent captured in the room are minimal. 500w of heat is 500w of heat and will heat the room like 500w of heat will. Sure you might have a slightly different temperature distribution in the room but again heat does try to dispurse and the temperature rise of the room over time will be similar. Again I feel like as someone who designs hvac systems for a living you are way overcomplicating things. 

I agree, that point was specifically to counter the premise that, "At room scale 500W is 500W regardless of the way it's dispersed," which is technically false. I use the direction and magnitude of heat flux with respect to the largest heatsink out of the space, and electromagnetic radiation as examples, since radio waves do deposit kinetic energy that can be described as joules/second into matter that attenuates it (obviously not as much as higher frequency electromagnetic radiation but I'm not about to start talking about x-rays and gamma rays).

 

Its about being precise in language to mitigate improper application of such a principle to categories where it's not supposed to, something that using precise language fixes.

[Brooksie359]

49 minutes ago, Agall said:

I agree, that point was specifically to counter the premise that, "At room scale 500W is 500W regardless of the way it's dispersed," which is technically false. I use the direction and magnitude of heat flux with respect to the largest heatsink out of the space, and electromagnetic radiation as examples, since radio waves do deposit kinetic energy that can be described as joules/second into matter that attenuates it (obviously not as much as higher frequency electromagnetic radiation but I'm not about to start talking about x-rays and gamma rays).

 

Its about being precise in language to mitigate improper application of such a principle to categories where it's not supposed to, something that using precise language fixes.

If you had organically just said radio waves then I might see your point but you said mechanic energy like with the fans which like I said will eventually be converted to heat. Also technically correct is also not technically correct when looking at scale. You make generalizations about things that matter at scale that don't. I mean it's like someone asking about when they should replace their car oil and then someone going on to describe the purpose of oil and how friction works. 

[Agall]

Just now, Brooksie359 said:

 I mean it's like someone asking about when they should replace their car oil and then someone going on to describe the purpose of oil and how friction works. 

Is there something wrong with answering both? I see no problem with answering the question and then going into detail on why I believe that answer is correct. It subjects you to more scrutiny since an answer could be correct for the wrong reasons, but in my opinion, that's the goal of doing so, for the sake of truth and accuracy. In the end, everyone wins.

[WoodenMarker]

3 hours ago, ChrisLoudon said:

The PC is doing it more slowly as heat moves from the IHS > Heat Sink > Inside Case > Case > Desk > Cavity........ 

It's not much slower. The heat output should be constant as soon as PC temps stabilize.

 

In regards to heating a room with 500W, a hair dryer and PC are practically the same.