…heaters are the one thing that’s 100% efficient. And if you want to go even further, look up heat pumps.
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bitfucker@programming.dev 6 months agoDude, even heaters cannot get to 100% efficiency.
faultyproboscus@sh.itjust.works 6 months ago
bitfucker@programming.dev 6 months ago
I mean, kinda? What sort of heater are we talking about and how do we measure its efficiency? But, if the definition is just converting energy to heat, without specifying where the heat needs to be, then sure. Every heater has 100% efficiency. Otherwise, there will always be a loss at transport and others.
taladar@sh.itjust.works 6 months ago
The point is that even with 100% efficiency you couldn’t get enough water out of the air because the dry air simply doesn’t hold that much water.
alberttcone@sh.itjust.works 6 months ago
That’s 17g or 17cc per cubic metre, not 17 litres!
In dry countries the relative humidity can be low - sub 40% is common. That said, the absolute water carrying capacity increases rapidly with temperature, so at 40C, the saturation mass is more like 50g/m3 and at 40%RH it still carries more water than 100%RH air at 20C.
taladar@sh.itjust.works 6 months ago
You are correct, I got the wrong numbers. But with your numbers of course it makes even less sense.
alberttcone@sh.itjust.works 6 months ago
You are right that you need to dehumidify a large volume of air (like, more than 150 cubic metres) to get enough water for a person, in a rationing scenario. That isn’t necessarily a huge problem; fans can move large volumes of air quite efficiently and dehumidifiers work more efficiently at higher temperatures, but your main point that it isn’t scalable on a population level is definitely true - it’s something you can do for off grid or survival situations, but not easily for domestic water supply.