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electric dissipation

look ma no fans!
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This is a proposed cooling and air moving system with no moving parts (except the air, which isn't a part).

In solar fruit driers the hot air moving upward creates a strong draft pulling after it the air from the bottom. The same happens in smoke stacks and chimenies. So this idea is about an effect similar to "moving lights" that work by switching on LEDs or flaurecent lights in sequence only here we use electric heat elements or infra-red LEDs. This creates a draft of hot air moving out of the pipes and pulling cold air in.

The cool air could pass first in a heat exchange chamber where it collects heat from the units that need cooling, especially the CPU. The dissipation of heat into the chamber could be assisted by a peltier device, although not very efficient, but sufficient enough in our case to quickly move the heat off the unit and into the coper fins for quick dissipation.

This could

pashute, May 09 2018

Heat art? https://www.deviant...sturbance-245646124
This would be interesting as a heat-xel if real [wjt, May 12 2018]

[link]






       Could it?
pertinax, May 09 2018
  

       Of course it could. He said so.
MaxwellBuchanan, May 09 2018
  

       Now I can't.
ever erase that mistake.
pashute, May 09 2018
  

       OK, so you want to electrically heat air, so that it rises by convection and cools things?
MaxwellBuchanan, May 09 2018
  

       would the coanda effect work with this?
beanangel, May 09 2018
  

       //electrically heat air//   

       No, I think the electrical heat is already a given, such as, for example, the heat from your laptop.   

       I think the idea here is to add a convenient chimney to your laptop, in place of the fan. But it might
pertinax, May 09 2018
  

       …startle giraffes
Ian Tindale, May 10 2018
  

       I think a laptop chimney would
pocmloc, May 10 2018
  

       The interesting bits would be the heat-xels and their workable sizes. Aah, the beauty of the informational driving patterns and the motions of painted smoke.
wjt, May 10 2018
  

       What's a xel?
MaxwellBuchanan, May 10 2018
  

       Except for the trailing "This could" which was supposed to be replaced by the current text and instead got pushed down to the end, the rest is quite clear, me thinks.   

       Yes I do want to electrically heat a pipe's sections in a way that causes the air to flow one way, leading the air out and away from the laptop. Once the flow is established, it can take the heat from the laptop parts and take it away through convection, just like a fan does.   

       Not a magical notion, and not something that is wishful thinking, this is a practical and doable thing pending the problems and flaws that the ever watchful HB team will find, of course.   

       Of course this might startle giraffes, but what are they doing in the laptop in the first place.   

       As a second thought I could probably
pashute, May 10 2018
  

       So, [pash], what you're suggesting is that a simple six-foot chimney, connected to the laptop, and with strategically- placed heaters consuming only a few hundred watts of power, could replace the cumbersome half inch-tall fans that gobble up perhaps a watt of electricity?   

       Why, the benefits seem absolutely enormous.
MaxwellBuchanan, May 10 2018
  

       Solar updraft towers work with a roughly constant and uniform application of heat to the collection area. So what's your goal in trying to peristalt the heat?
notexactly, May 11 2018
  

       Let's think about the power requirements.   

       Let's assume your computer fan is about 2W, and moves about 3 cubic metres of air per minute.   

       Now we replace it with this heated cooling tower (the name, there, gives you pause for thought). Let's also assume that the heater in the tower raises the air temperature by 10°C in order to achieve a reasonable flow.   

       So, we're heating 3 cubic metres of air per minute by 10°C. That's about 3kg of air, with a heat capacity of about 1kJ/kg, meaning you need about 30kJ/min for the heating. That's about 500W of power.   

       So, this system would be on the order of 250 times less efficient than a fan.
MaxwellBuchanan, May 11 2018
  

       //So, this system would be on the order of 250 times less efficient than a fan//

You could be a bit more 'glass half-full' about it - e.g. "...this system would be only 250 times less efficient than a fan!"
hippo, May 11 2018
  

       Also, just moving air about is an inefficient answer to the problem of cooling. A cooling system like this has hot things in it which require cooling, and a cooling medium which ideally has a reasonably high heat capacity (unlike air) and a high thermal conductivity (unlike air).

The two reasons to move air about are (1) to move hot air away once it has absorbed some heat and (2) because the air will absorb more heat the higher the temperature difference between the thing that needs cooling and the air is. Moving air faster and faster might seem like you're doing something but beyond a certain point it probably only changes the temperature of the air near the thing that needs cooling by a fraction of a degree (outweighed by all the heat being transmitted by the fan motors), and the limiting factor is actually the thermal conductivity of the cooling medium. I.e. no matter how cool the air, there is a limit to the amount of heat it can absorb per second and carry away.

It is for these reasons that people use water-cooling on very hot computers or even exotic alloys of indium and gallium (which conveniently are liquid) for more specialist cooling jobs. Even with these though, the limiting factor is thermal conductivity, not your ability to pump the cooling medium around.
hippo, May 11 2018
  

       In fact, consider how woefully inefficient air is as a coolant: You're outside on a winter's day walking along with a freezing gale blowing in your face. Your face is putting out only a few 10's of watts of heat (at the most) but still doesn't get frozen by the gale, because air is a very poor conductor of heat.
hippo, May 11 2018
  

       //What's a xel?// That's 'heat-xel' and it's a Maxwell demon swinging forging hammer to heavy music.
wjt, May 11 2018
  

       Ever come across a heat pipe ?
bigsleep, May 11 2018
  

       Heat pipes get most of their effect from phase changes, i.e. evaporation of liquid at the hot end, and condensation at the cold end.
MaxwellBuchanan, May 12 2018
  

       //the air will absorb more heat the higher the temperature difference between the thing that needs cooling and the air is//   

       So, if we make the thing hotter, it'll be cooled more efficiently by the air.   

       There's an idea in the making!
Wrongfellow, May 12 2018
  

       {starts working on a steam driven punkah-wallah}   

       Anyway I think this is a situational wossernames.   

       I presume that pashute lives in a sunny place. So a metal chimney can be painted black, sunlight heats chimney, convection occurs etc etc   

       In England, you'd just end up with a black metal chimney, with the paint drying out sometime the heavy, cold rain stops.
not_morrison_rm, May 12 2018
  

       I though this idea was about better controlling the heat transfer medium. Designing it's flows to a more complex level with little subunits rather than just globbing heat at one end and taking the resultant cooling effect at the other.
wjt, May 12 2018
  
      
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