4 ms·
Do these devices have the effect of cooling the air? The energy has to come from somewhere… If so, that would potentially serve two purposes for the price of on
by ttul 3y ago
Do these devices have the effect of cooling the air? The energy has to come from somewhere… If so, that would potentially serve two purposes for the price of one: cooling and power generation. Or, is the side effect to make the air less moist. Also a useful function, particularly in humid places where drying the air is desired.
- willcipriano 3y agoI have a pet theory that in the future air conditioning will generate small amounts of electricity rather than requiring a great deal of it. I think perhaps a large volume of these, self powering a fan could fit the bill.
- klysm 3y agoUnder what atmospheric conditions is that possible while preserving conservation of energy?
- willcipriano 3y agoSomething like this looks promising. If you can remove humidity and get a little power you might for example power an ultra efficient heat pump with that power then use say a peltier device to charge your phone off the hot side. Edit: another idea use this to reduce the humidity in the air, then use the captured moisture to enable a swamp cooler. It requires improvements in the efficiency of everything but I think it's possible in say a few hundred years.
- TeMPOraL 3y agoNot if some of those improvements have reach bona fide >100% efficiency. Whatever you do, you will be adding heat/entropy to the system somewhere. Even the most efficient heat pumps heat things up on the net - they cool by moving heat around, and then they add their own waste heat on top. The trick is, and always has been, to make sure your waste gets dumped somewhere you don't care about. A heat pump will dump its waste heat along with the heat it moves out of the place you care about, like inside your house, to the place you don't care about, like the ground beneath your house or the air outside. Other such tricks include dumping heat into rivers and lakes (see: most power plants), routing it where you need things heated up (see: combined heat and power plants), or just dumping it to space (Earth's atmosphere happens to be transparent at certain IR wavelengths, allowing you to use the universe as your heat sink). There's space for more sophisticated trickery, trying to minimize waste by reusing everything as part of some process elsewhere. But the net entropy still has to grow, so the main question is the same as it always has been: where do you dump waste heat?
- vineyardmike 3y ago> There's space for more sophisticated trickery, trying to minimize waste by reusing everything as part of some process elsewhere. But the net entropy still has to grow, so the main question is the same as it always has been: where do you dump waste heat? Not OP, but wouldn't the "ideal" be to pull any excess heat (energy) out of the interior air, and use it first for electricity-needs in a home like phones, toasters, etc (which generate heat). That heat will eventually be re-captured by the heat-extractor, and can be recycled - any excess heat can still be "dumped" outdoors, and "ideally" the energy required to "move" that heat outdoors is first pulled from the spare-heat of inside. Obviously the big question in this scenario is how to convert heat into electricity, without a temperature differential. AFAIK we haven't figured this out.
- CorrectHorseBat 3y ago>Obviously the big question in this scenario is how to convert heat into electricity, without a temperature differential. AFAIK we haven't figured this out. Wouldn't that mean you create energy out of nothing breaking the first law of thermodynamics or that energy goes from a colder body to a warmer body, breaking the second law?
- short_throw 3y agoYou will find the second law of thermodynamics very disappointing.
- uoaei 3y agoAssuming the system is exposed to open atmosphere, and knowing that free electrons have higher energy than bound electrons, it's not clear what you're trying to imply here. Especially since entropy increasing only applies to closed systems.
- jojobas 3y ago[flagged]
- uoaei 3y ago[flagged]
- syntaxing 3y agoNot OP, but I'm not sure what you're trying to imply...going from liquid to gas phase change is going from lower entropy to higher entropy. There is no laws of thermodynamics being broken. And for your note for closed system, control volumes are defined as the system you're looking at. There is no "scale" when it comes to it (whether your control volume is the Earth, universe, or your room). Laws of thermodynamics cannot be broken regardless of your control volume size (as long as you obey the continuous limit theorem).
- dvh 3y agoWait till you find out what people do with electricity.
- regularfry 3y agoI can't see how you'd avoid it. The charge on the molecule is going to be one of the things keeping it repelled from other water molecules, so as you take charge off it, there are fewer internal forces to keep them apart. That's got to be a reduction in the vapour pressure, right? In the right circumstances the water will condense out. I think that's got to be the engineering limit of the "stack of thousands of sheets" idea they mention: somewhere down the stack they short out because water droplets will condense out into liquid on the sheet. This all assumes a net charge one way or the other on the body of water vapour. The article doesn't make it clear but I assume that's inevitable.