Volvo Repair: A/C, cluth, humidty

Question
My wife has a 1999 S70 with a 2.4L.  Her A/C is very cold when it works, however sometimes for no reason it just stops.  The air will keep blowing, it changes smell a little and the humidty seems to go up the it just continues to warm up.  One service man said it was the compressor, and it would cost $1,100.00 to fix.  I am thinking it might be the cluth?  If it is the culth is there any treatment besides a whole compressor replacement?  Any direction would be a huge help.  thank you,
Jim

Answer
Jim, I think $1100 is a bit steep but it is better to change the compressor instead of just the clutch.  To give you and example.  If a compressor costs 400 new and just a clutch is 300, then I want to spend the extra 100 bucks on a whole compressor because at any time, the compressor may dump as well.  Its just not cost effective to change just the clutch.  Hope this helped.  Roger