Air conditioning

[Keith Roberts]

> Reminds me of the argument between two technicians about whether
> air conditioning lowered relative humidity or raised it.  They
> were both right, only one was in Arizona and the other in Florida.

There are two different types of cooling air conditioners. A
freon/compressor type which will dry the air out and is a closed system (no
outside air).
Correct me please if this next statement is wrong. Air which is already dry
and can't get much drier will have a higher RH at 80* than 100*.  (* means
degrees F ).
    RH around here (gold country, California) dropped to 8% these last
couple of days. The skin cracks in an air conditioned house. So I'm not sure
if the RH goes up at all. I know it does when the temperature starts to drop
in the evening.
    The other type is an evaporative (swamp) cooler. It is an open system
and windows need to be open to not back pressure the blower. They will not
work in a humid enviroment as there is no room for the water to evaporate.
At 100* outside with a RH of 20%, a swamp cooler will blow 75* air with a RH
of 70%. At the piano (mine) the RH was 47%.
    I recommend people put in a swamp cooler around here even if they have
the other type of air conditioning. It can be ducted instead of sitting in
the window and is cheaper than adding a humidifier to the compressor type.
It is a more pleasing air and far cheaper to run than the compressor type.
The compressor type becomes a fine back up on the five (maybe) days a year
the swamp cooler doesn't work.
Keith Roberts