Re: Coupe Quattro 90 air conditioner question.

[LToy@aol.com]

Bob D'Amato writes:

>> close up the system and recharge.  Pulling a vacuum on the system before
>> recharge won't get the moisture out of the thing.  This may be what's
>causing
>> 
>
>Sure it will. The whole point of pulling the vacuum is to get rid of the 
>moisture. Remember our pressures and heat of vaporizations? Neither do I, 
>but thats not the point! :)   THe lower the atmospheric pressure in a 
>system, the lower the boiling point of water. So if they get it down to a 
>few mm hg, the water will literally boil away, even at ambient temps.
>I beleive the vacuum must be held for 4 hours or something like that.

Generally agreed.  Maybe I shoulda said "won't get all the moisture out"
No, I'm not an HVAC specialist, but I'm led to believe that the
receiver/dryer has some chemical that grabs moisture out of the system and
hangs on to it--the vacuum can't get it all out, and the chemical now has
that much less capacity to absorb new moisture in the system--leading to our
friend's problems with freezing A/Cs.  

ldt.