Originally Posted by J.Harris
...Like when the hot water comes out of the shower head a tiny amount of it evaporates and that is what you see on the mirror?
Well, no, the water concensing on the mirror is not a demonstration of the "bong cooler" concept.
If you put the shower head on as fine a droplet size as you can and feel the diffrerence in water temperature between where the water exits the shower head and just before it hit the floor, that temperature difference is how a bong cooler works. The water cools as it evaporates, so it's cooler after it falls through the air in the shower. So, you see that the water recondensing on the mirror has nothing to do with how a bong cooler works, other than demonstrating that the humidity in the room with the bong cooler in it will skyrocket from all the evaporated water.
You can also see the effect of droplet size on cooling by turning the shower head to as large a droplet size as possible and checking the temps again.
And as stated, you'll have to learn to use a psycrometric chart.
You may want to demonstrate this effect to your GF too..........(;])