Using PC as Space Heater

[boarder2k7]

An electric space heater usually draws a couple thousand watts.

The big ones are 1500 W. A bathroom heater maybe 800 or so, and a toe kick under desk heater maybe 250. You're technically allowed a max of 1800 Watts from a 15 A 120 V circuit, but that's FULLY loaded so it's difficult to find things that large. I think 1650 W is the most I've seen out of UL listed appliances without a 20 amp plug on them.

​Also, if you pay for electricity, it's a huge waste. PC's are designed to produce as little heat as they can, relatively speaking, they aren't designed to efficiently produce heat relative to how much power they consume.

They're only designed to use less power, all the power becomes heat.

It's no more wasteful than electric space heaters; PCs are precisely as efficient at converting electricity to heat.

This.

For reference, each Watt is 3.41 BTU/hour for comparison to a normal heat plant.

Nah...

That's a dB meter not a thermometer!

[Sakkura]

The big ones are 1500 W. A bathroom heater maybe 800 or so, and a toe kick under desk heater maybe 250. You're technically allowed a max of 1800 Watts from a 15 A 120 V circuit, but that's FULLY loaded so it's difficult to find things that large. I think 1650 W is the most I've seen out of UL listed appliances without a 20 amp plug on them.

The regular sizes here are 2000 and 1500, with beefy versions at 3000 and even a few above that.

[J. Hammond]

Why do you need end room temp? I'm looking for end room temp.

Room temp now is about 19C

Room volume would be 36m3

Maybe 30minute benchmark?

Average cpu temp would be 45C because my cooler causes it to stay at 45C. But that isn't accurate because that's not how much the cpu is. But we'll use 100W as baseline (How does the conversion work..??)

 

How good is your home insulation? There's no point of heating your room if it's going to be radiating away.

[Raytsou]

How good is your home insulation? There's no point of heating your room if it's going to be radiating away.

I have no way of measuring, but I don't think it's that good. But the heat lost should be supplemented by the radiator, light sources, and body heat.

[Raytsou]

So after doing all my math and such I was able to calculate that with your PC putting off about 450,000j of energy per hour (about what you'd expect with a 250w draw from the wall) I was able to calculate the you could expect a 14.629°c rise in temperature in your 36 cubic meter room, however you have to take into account any potential thermal leaking through windows, door frames, walls, etc. So realistically you'd see a 10°c rise in temperature that seems rapid initially however eventually slows down and stops.

Also keep in mind that this would not be linear as your room would eventually reach thermal equilibrium. Here is the math / equations-

 

screenshot-docs.google.com 2016-01-04 21-50-46.png

Thanks, man!

In the meantime I'll wear a hoodie.

[boarder2k7]

The regular sizes here are 2000 and 1500, with beefy versions at 3000 and even a few above that.

Ahh yeah that's a 120/240 thing. Still a 15 Amp circuit but you get double the wattage.

How good is your home insulation? There's no point of heating your room if it's going to be radiating away.

While this is true, it's also true that home heating is in the end, a 100% loss.

Spot heating just where you are is more efficient in an otherwise poorly insulated situation though.

[DatScreamer]

space heaters @ Canadian Tire or wherever are like $20/$40. Just buy one of those. Way more power efficient

[boarder2k7]

Way more power efficient

No they're not, they're exactly the same power efficient. A watt is a watt regardless of what uses it. You could use 100x 6 watt LED light bulbs, 10x 60 watt incandescents, or a 600 watt space heater, it's all 600 watts. Some of the options are just brighter than others.

If you have electric heat anyway or are going to spot heat, running something like FaH is a nice way to make that energy serve a purpose.

(This is of course ignoring power factor differences of VA compared to Watts, but this doesn't matter in the home market, as non-industrial users are not penalized for power factor in any metering rate I am aware of.)

[vanished]

how many degrees will the cpu heat up my room per second?

That's a relatively complex calculation that depends on a lot of things we don't know, like the insulation in your walls, how many are external, the amount of air circulation in adjoining rooms/outside, etc. etc.  This is because "how many degrees per second" will actually change over time as a result of those variables.  But I can tell you now that in those units (degrees per second), it will be a very small number

[Tmt97]

Heres some new perspective on the matter. You might not need to heat the whole room. You just want to keep yourself warm, im assuming. I have the same cpu as you, and a radeon 7950 graphics card. If i run a game on it, with it right next to me. It blows enough hot air on me to keep me warm. It doesnt seem to change the overall room temperature much, but if its just for me then that doesnt matter. In fact this is an actual solution that i use now. Normally id wrap myself in 3 blankets, now i just sit next to my pc with it oriented so it blows air at me.

[Sakkura]

That's a relatively complex calculation that depends on a lot of things we don't know, like the insulation in your walls, how many are external, the amount of air circulation in adjoining rooms/outside, etc. etc.  This is because "how many degrees per second" will actually change over time as a result of those variables.  But I can tell you now that in those units (degrees per second), it will be a very small number

 

Yeah, that calculation earlier in the thread is a MASSIVE oversimplification.

[Geralt]

Ahh winter overclocking.

 

Crank that clock and voltage up and put on a stress test. You'll be warm in no time.

[Raytsou]

That's a relatively complex calculation that depends on a lot of things we don't know, like the insulation in your walls, how many are external, the amount of air circulation in adjoining rooms/outside, etc. etc.  This is because "how many degrees per second" will actually change over time as a result of those variables.  But I can tell you now that in those units (degrees per second), it will be a very small number

I see. My question should of been phrased better, like, how much heat my computer is outputting into my room in Celsius. But I also wanted the effect on an area of 36m^3. It was a spur of the moment thing, and I was just curious if I would make my room any noticeably warmer by gaming for a while.

[Raytsou]

Why did this get moved to air cooling . If anything, it's air heating.

[vanished]

I see. My question should of been phrased better, like, how much heat my computer is outputting into my room in Celsius. But I also wanted the effect on an area of 36m^3. It was a spur of the moment thing, and I was just curious if I would make my room any noticeably warmer by gaming for a while.

 

Absolutely you can make the room warmer, but calculating the exact amount and speed that it will occur at is (given the limited information we have) actually impossible.  Just do it and see for yourself what a difference it makes using an ordinary thermometer.

 

Oh, and it wouldn't output heat in Celsius  That's a measure of temperature.  It would output an amount of energy during a certain span of time (in Joules, for example) or it would continuously output a certain amount of power (heat) in Watts for example.

[ManWithBeard1990]

That's not a particularly big room so there will be noticeable impact. If you can live with the noise, of course

Even an overclocked APU will keep my room at a reasonable temperature.

[DatScreamer]

No they're not, they're exactly the same power efficient. A watt is a watt regardless of what uses it. You could use 100x 6 watt LED light bulbs, 10x 60 watt incandescents, or a 600 watt space heater, it's all 600 watts. Some of the options are just brighter than others.

If you have electric heat anyway or are going to spot heat, running something like FaH is a nice way to make that energy serve a purpose.

(This is of course ignoring power factor differences of VA compared to Watts, but this doesn't matter in the home market, as non-industrial users are not penalized for power factor in any metering rate I am aware of.)

(Facepalm) A space heater with a large radiator is going to heat a room up much faster than a cpu with a lot less surface area. CPUs are designed to stay cool where as space heaters are designed to radiate heat. A space heater will heat a room faster giving less hot air a chance to cool then does not have to work as hard (Use as much energy) to keep the room at that temp. a Space heater can be 99% efficient, a CPU will not. Don't argue with me.

[vanished]

A space heater with a large radiator is going to heat a room up much faster than a cpu with a lot less surface area. CPUs are designed to stay cool where as space heaters are designed to radiate heat. 

That's true.  And for that reason, and the fact most space heaters are on the order of 1500 W, while computers are only a few hundred, is why a heater will heat your room more and more quickly than a computer.  However, if you had a heater and a computer that both produced the same amount of heat, they would heat the room at the same rate.

 

As for this:

 

A space heater will heat a room faster giving less hot air a chance to cool then does not have to work as hard (Use as much energy) to keep the room at that temp. 

 

How hard <whatever> has to work to keep the room at that temperature is just a measure of how much heat it has to output in order to do so, and this is exactly equal to the rate of heat loss from the room through walls.  Since the rate of heat loss through the walls is only a function of the temperature of the room, the temperature outside the room, and the amount of insulation between those two zones, all that is necessary to maintain the room at that temperature is the continuous output of the right amount of heat by something in the room.  Whether that is a heater or a computer is irrelevant and makes no difference in terms of efficiency.

[Sakkura]

CPUs are designed to stay cool where as space heaters are designed to radiate heat. A space heater will heat a room faster giving less hot air a chance to cool then does not have to work as hard (Use as much energy) to keep the room at that temp. a Space heater can be 99% efficient, a CPU will not. Don't argue with me.

 

CPU coolers are designed to keep the CPU cool, yes. But how do they do that? By transporting the heat out of the CPU and into the surrounding air as quickly as possible. That's exactly the same thing a space heater is designed for, just with a different heat source.

 

A space heater will only heat a room faster to the extent that it uses more power.

 

Both a CPU and a space heater will be 100% "efficient" at turning the consumed electrical power into heat.