"Peter H" wrote in message
...
I'm hoping someone in this group will take the time to answer this for me.

I'm in the middle of a course on HVAC in high-rises. The instructor has
stated that the oil in the HVAC system should be checked regularly for
quality and impurities. She says that if refrigerant is detected in the
oil
then there is a problem. I was always thought that there is oil in the
system with the refrigerant and that this oil lubricated the compressor
etc.and one would expect to find refrigerant mixed in with it. I thought
that this was why you are always told to let a newly delivered fridge
stand
for an hour or two before turning it on, to let the oil drain back down
into
the compressor.

What gives?

tia

Peter H

I believe you will find in the real world, "if it aint broke don't fix it".

I have never heard of anyone taking and testing oil samples on refrigerant.
Unless there was a problem with the unit.
Every high rise I ever worked on had compressors and air handlers in a
mechanical room.
Cooling and heating was transferred either directly (air) or by another
medium (water).
Being the cost per square foot is so high the idea of huge duct work from
the roof or basement has not been used for years. At least not here. Then
there is the fire concern with large vertical ducts.