Gary Meek wrote:
> 
>         I have heard it said that if your freon circuit has been left open
> to the air for a long period, that when recommissioning the AC, you
> are enjoined to replace the receiver/dryer.
> 
>         I have two questions:
> 
>                 1. Is the receiver/dryer composed of some sort of desicant
> material, to absorb any moisture from the freon?
> 
>                 2. If the answer to #1 is yes, then can I gently toast the
> receiver/dryer the the oven for a few hours, at say 100 degrees C,
> to drive off any accumulated moisture, and then reinstall the unit in
> my AC freon circuit?
> 
>         And no, don't ask why I am recommissioning the AC, with
> 30 cm of the white stuff on the ground!
> 
>  gary meek
>  sherwood park, alberta, canada
> 
>  82 Vanagon GL  1.6 litre turbo-diesel
>  83 Quantum SW 1.6 litre turbo-diesel
>  83 Audi  4000S  1.6 litre turbo-diesel

Your AC dryer does have a desicant, most likely a molecular sieve.  These can be regenerated 
but will require more than 100 degrees C and a dry gas purge or good vacuum while heating.  
It would be best to replace the dryer.  There is also oil in the system that will also be in 
the dryer and will likely be a problem during regeneration.

Larry