4 ms·

Swamp coolers cool based on evaporative cooling: water evaporating into dry air reduces the (dry bulb) temperature of the air. So with high wet bulb temperature

Swamp coolers cool based on evaporative cooling: water evaporating into dry air reduces the (dry bulb) temperature of the air. So with high wet bulb temperatures indicating air is already saturated with moisture, the swamp cooler won't work.

newbamboo 5y ago
Dehumidifiers are a thing. I presume that having water and electricity is a bigger problem for most people, but I’d love to be educated more on the problem, if you have links or literature.
- wtallis 5y ago
  Dehumidifiers are air conditioners that put the heat back in the air they treat instead of dumping it outside. Your electricity would be better spent operating a real air conditioner.
  - hasmanean 5y ago
    Or you could use an Einstein-Szilard (aka absorption) refrigerator that works without electricity. It’s driven by heat. It uses 3 gases (butane, ammonia and water.) It has no moving parts so it’s safe. Someone could make a “Einstein dehumidifier” using 19th century technology and roll it out across the world. If embedded in buildings it could cool them constantly with no electricity required.
- toast0 5y ago
  (Commercially available) Dehumidifiers are basically small air conditioners with both the hot and cold side in the same room. You can't run them without electricity, and if you can run a dehumidifier, you may as well dump the heat outdoors instead and cool and dehumidify your space.
- vidarh 5y ago
  Yes, but combining a swamp cooler and a dehumidifier is most of the way there to a modern AC unit, both in concept and electricity need. Most modern ACs in fact dehumidify and cool in one step with a compressor and then use the collected water to help carry heat away from the compressor by letting the water evaporate into the exhaust to save power (it's why you rarely have to empty water from modern dehumidifying ACs).
- saeranv 5y ago
  I'm dissappointed to see you're being downvoted for what looks like a good faith (and common) misconception with a request for more information. Anyway, the best way to learn more about this is to search for resources describing the "psychrometrics of evaporative cooling". Psychrometrics is the study of the thermodynamics of air and water vapor mixtures. Learning about the psychrometric chart, in particular, is helpful since it is a very clear, expressive tool that will illustrates how adiabitic (no change in thermal energy transfer) cooling can occur by adding humidity to dry air. I think this entry from engineering toolbox provides a good start: https://www.engineeringtoolbox.com/evaporative-cooling-d_698.html1 https://www.engineeringtoolbox.com/evaporative-cooling-d_698...

newbamboo 5y ago

Dehumidifiers are a thing. I presume that having water and electricity is a bigger problem for most people, but I’d love to be educated more on the problem, if you have links or literature.

wtallis 5y ago
Dehumidifiers are air conditioners that put the heat back in the air they treat instead of dumping it outside. Your electricity would be better spent operating a real air conditioner.
- hasmanean 5y ago
  Or you could use an Einstein-Szilard (aka absorption) refrigerator that works without electricity. It’s driven by heat. It uses 3 gases (butane, ammonia and water.) It has no moving parts so it’s safe. Someone could make a “Einstein dehumidifier” using 19th century technology and roll it out across the world. If embedded in buildings it could cool them constantly with no electricity required.
toast0 5y ago
(Commercially available) Dehumidifiers are basically small air conditioners with both the hot and cold side in the same room. You can't run them without electricity, and if you can run a dehumidifier, you may as well dump the heat outdoors instead and cool and dehumidify your space.
vidarh 5y ago
Yes, but combining a swamp cooler and a dehumidifier is most of the way there to a modern AC unit, both in concept and electricity need. Most modern ACs in fact dehumidify and cool in one step with a compressor and then use the collected water to help carry heat away from the compressor by letting the water evaporate into the exhaust to save power (it's why you rarely have to empty water from modern dehumidifying ACs).
saeranv 5y ago
I'm dissappointed to see you're being downvoted for what looks like a good faith (and common) misconception with a request for more information. Anyway, the best way to learn more about this is to search for resources describing the "psychrometrics of evaporative cooling". Psychrometrics is the study of the thermodynamics of air and water vapor mixtures. Learning about the psychrometric chart, in particular, is helpful since it is a very clear, expressive tool that will illustrates how adiabitic (no change in thermal energy transfer) cooling can occur by adding humidity to dry air. I think this entry from engineering toolbox provides a good start: https://www.engineeringtoolbox.com/evaporative-cooling-d_698.html1 https://www.engineeringtoolbox.com/evaporative-cooling-d_698...