Does a quiet PC generate less [] heat?

[okjunga]

I'm considering building a new system and have been overwhelmed by the knowledge and generosity of the users of this site and forum.

I have three concerns that have led me to want to build my own system (other than I enjoy doing such things).

1) value
2) managing heat in my room
3) managing noise

We currently have two computers in an upstairs room. When both are on, the room is noisy and, during the summer, hot (2-3 degrees hotter than the other rooms).

If I select components to build a quite PC, will I also end up with a PC that generates less ambient heat? Or, do I need to do other things to deal with the ambient heat problems when I build my PC (such as a dedicated cabinet, venting heat out of the room, placing units in a closet, etc)?

Note, I am not concerned about the heat within the unit, as there is plenty of advice here to deal with that. Also, I'm not interested in turning down my A/C

Thanks.

[ryboto]

Just because you use silent-focused components doesn't mean your system wont generate a lot of heat. For instance, you could throw undervolted Nexus fans in a P-D based system, sure it will be silent, but you're going to have a warm pc. The idea is to select power efficient components so that you don't have to worry about heat in the first place. Unless you're using a water cooling system, higher power systems are harder to keep cool with a silence-in-mind air cooling setup.

[IsaacKuo]

Generally, choosing components for quietness will also mean choosing components which generate less heat. In particular, choosing an efficient PSU can have a big impact on the total heat generated. The total wall-plug power draw will be equal to the heat generated. Going from a 60% efficient PSU to an 80% efficient PSU means a 25% reduction in the total heat generated.

Another big thing can be the heat generated by the computer monitor(s).

One thing which will NOT have a significant effect is how fast/slow you run the fans. The power draw of the fans themselves is not much, and the amount of airflow only changes the computer's internal temperature without changing how much overall heat is dumped into the room.

[cloneman]

Might be obvious, but selecting lower power (more efficient) CPUs and video cards will have some impact on the heat released into the room. CPUs that support cool & quiet or speedstep are great as well.

[jhhoffma]

I'd say it the other way around. Choosing low-power components would make it easier to keep quiet and more energy efficient.

[Atmosper]

It will add some ambient heat, although not much. Generates about the same as having another person in the room (except for a really HOT chick ).

[Chris Chan]

So humans are around 150 watts? How can I convert calories to watts? (serious question, though it may not look it)

[IsaacKuo]

How can I convert calories to watts?

Exercise.



Seriously, a calorie is a unit of energy, while a watt is a unit of power--power is energy/time. They aren't directly convertible, because you need to specify an amount of time involved.

However, you can figure out a person's average power by taking his total caloric intake in a day and dividing by 24 hours. A nutritionist's Calorie is equal to 1000 calories, or 4184 joules. A watt is equal to one joule per second, so 4184 joules per day is equal to about 1/20 watt.

Thus, take your total caloric intake in a day and divide by 20, to get your average wattage.

[Atmosper]

So humans are around 150 watts?

Depends on the physical activity. An adult sitting down resting radiates about 100 W or 1 W/kg (depending on which study you look at, the latter is the more recent approximation I think).
However it depends heavily on the physical activity. Sweeping floors ~twice the heat, climbing stairs ~14 times the heat output .

[ronrem]

So humans are around 150 watts?

Depends on the physical activity. An adult sitting down resting radiates about 100 W or 1 W/kg (depending on which study you look at, the latter is the more recent approximation I think).
However it depends heavily on the physical activity. Sweeping floors ~twice the heat, climbing stairs ~14 times the heat output .

superglue a couple of Ninja's to your head and you'll be amazed at the difference.


----but......as to the main point...if you are going with a 400 dollar overclocked cpu and a 400 dollar mega vid card to do a gamer super-rig,it makes WAY more heat than a vanilla Sempron machine. Getting the excess heat out of the case-into the room-then becomes where you get NOISE,because a Hot Rod puter won't cool passive.

Now there's even single core AMD 65nm cpu's,similar to a Venice 3000 but even less power hungry and cooler. These will,especially if undervolted,hardly warm a Ninja. They may not have the "power" of the Ultra-Gamer-Beast machine---yet will blow away the XP's and P4's that were the Gamer machines a few years back,can EASILY do damn near anything most folks need-perhaps taking 5 sec longer.....but at less cost/heat/noise

For WAY CHEAP...you can get the "Low End" AMD and it's about the best cool-quiet going,probably heats the room less than a typical P3

The X2 or Core 2 chips are,for their performance,pretty good in terms of heat,but heat/silencing is always a trade-off. So, the key is avoid performance overkill

[NeilBlanchard]

Hello & welcome to SPCR,

All else being equal, a quietly cooled computer still puts as much heat as a noisy one. The only way to put out less heat is to use components that use less power -- which does also make it easier to keep it quiet.

I have 3 computers in this room, and it certainly does get warmer than the rest of the house; there is no avoiding this, unless your machine is extremely low power. If you keep it as low power as possible (60-75watts peak) then you may notice the difference, but all the machines would have to be of the same "class".

[Brians256]

I would bet that an accurate answer would have to be, "It depends".

Three things to consider:
1) Hotter components can draw more power. DC-DC voltage conversion circuits get less efficient when they are hot. The Rds(on) increases with temperature for MOSFETs.
2) Fans draw less power if you run them slower.
3) Changing components can change the power efficiency much more than #1 or #2.

If you don't change any components and just make the cooling more effective while lowering fan speed, then the power input would be less (unchanged power draw from the computer parts and lowered power draw from the slower fan(s)). Making the cooling more effective would be something like a more effective airflow pattern or changing an inert component such as a heat sink.

If you reduce cooling to gain silence (with the same components), then the power draw could be higher, lower or the same. The fans would draw less power, but the motherboard (especially the DC-DC power conversion) could be less efficient and draw enough more current to compensate for those fans.

The best solution would be to use more efficient components that are quiet. I love my fanless graphics card, but I don't mind having a less than state of the art GPU. My CPUs aren't overclocked, and I've spent good money getting a good case, quiet fans, high efficiency quiet PSU and a quiet and effective CPU heatsink.

[mcoleg]

excellent point and a good advise that most posters above make - choose components that don't produce much heat to begin with. this way you can keep cooling and therefore noise to a minimum.

if, however, you are building a high-powered or overclocked system, make sure the components get at least some active cooling (that includes ram and motherboard as well as vid. card and cpu). not only for the usual reasons - it runs hot, we have to cool it - another factor that is not often brought up is that the hotter the components run the more electrical resistance the psu has to deal with and thus it will work that much harder, in turn generating more heat and noise and increasing the risk of a failure.

this is not readily noticeable on low-powered systems ppl on this forum favor for 24/7 use so if you go that route, don't worry about it.

:p