Quote:
Originally Posted by Daox
I'm a bit confused, if he is dehumidifying the air... why would that make it feel more humid?
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It has to do with the difference between relative humidity, and the total water content of air.
Relative humidity is the amount of humidity in air divided by the maximum amount of humidity that the air can hold.
Hot air can hold more water.
Cold air can hold less water.
Here is a psychrometric chart...
If we have cold air (36F for instance) that is at maybe at 60% RH (blue dot on chart above), and warm it up (70F for instance), it will still have the same amount of water in it... but now, because it is warm, it can hold more water... so it's relative humidity would be lower. So the new relative humidity is 20% RH (red dot on chart above). And this is why your Wisconsin winters are so dry when you are indoors and you don't have a humidifier.
So here is what I think is pretty close to randen's shop when he was running ground water (assume 60F) through his converted heater...
The air temp was around 94F and 60% RF (red dot on chart above), it ran through the converted heater and hit the coils which were around 60F (blue dot) and SOME of the humidity condensed out, but not all, and the air was mixed and cooled to about 84F (green dot)... so the air is cooler at about 84F, and it has less humidity, but its relative humidity is now 70% RH instead if 60% RH.
If he put it through mechanical dehumidification, it would be something like this...
The coils on mechanical dehumidifier would be about 18F and moisture in the air would freeze onto the coil (it's not on the chart, but the black dot is as close as I could get), it would also chill the air quite a bit and when mixed, it would look similar to the magenta dot.
So the ground source would certainly help a lot, but if you already have a high level of humidity in your summer air, a bit of mechanical dehumidification will work wonders.
-AC_Hacker