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Old 07-28-2016, 10:02 PM
jjakucyk jjakucyk is offline
Join Date: May 2016
Location: Cincinnati
Posts: 255
Originally Posted by Gary T View Post
Observation: The OP asked about an ice cream bar, not about exposed ice cream in a cone or dish.

Question: Air conditioning by definition dehumidifies. Why is it being assumed that the output air is at 100% RH?
Because for an air conditioner to dehumidify it has to lower the temperature of the air passing through it below the dew point (100% RH) so the water vapor condenses and drains away. Cold saturated air pumped into a warm space dehumifies as it mixes with the ambient air. Or think about it like this, cool a small tank of air (something sealed tight, like a jug put in the refrigerator) until the water vapor condenses, then drain away the water. When you heat it back up the air inside will be drier than before. An air conditioner does the same thing just not to all the air at once.

In practice the outlet air is not exactly 100% because if it is then you'd see fog coming out the vents. It's still well into the 90% + range though, but since not all the air effectively touches the evaporator coil there's still some mixing going on to keep the outlet from being completely saturated.