Hello, Im new to this forum.
I have a brand new small R22 Fuji rotary (on/off) compressor which I
use for 407C and therefore an oil change to Ester type is neccesary.
Can only drain oil (~300ml) out of a hole I drilled close to the
connection (HP) non from the suction line (muffler is removed). From
what I have read there should be some oil also in the lower (suction)
Years ago, I drained the oil out of a window AC rotary, by
tipping it upside down. Then power it up, and the oil blows
out the high side.
You may be able to pump the new oil in, through the high
Drilling a hole in the compressor shell? I hope you have
the ability to weld it shut?
Yes welding is no problem, I know many refr engineers but no one knows
how to change oil...
If I only fill oil in the high side, will the suction side run dry
until oil has been recirculated?
Someday I should cut open one of those rotary compressors.
As I understand it, the high pressure side goes to the area
around the pump. If it were an automotive engine, what would
be called the crankcase. So, pumping oil in the high side
should be same as filling the crankcase. The oil should
lubricate nearly immediately. You won't get 100% of the old
oil out, so there should be enough to lube for the first
That's just my experience from trying it with one
Thats logical, but the reason is that got this new compressor for free
some time ago and it fits wery well (except for the oil) in my project
which will be much cheaper to realize if I dont have to buy a new one.
Everyone with ideas around oil change in rotarys are welcome!
No, this is a heat pump project, the evaporator is approx 50m copper
tube in the soil, the condenser is indoors blowing hot air. These
systems are quite common up in our arctic regions.
For me it is a low cost project were I can find most of the parts for
free since I work in conjuction with a refrigeration company.
Yes R22 should work and also it should work with the mineral based oil
in the compressor...but R22 is forbidden and not available in my
country since about 10 years :=(
The gas to use in these applications nowdays is (normally) R407C, wery
similar to R22 in pressure etc but ester oil is needed.
You could use NU-22 as a R22 replacement and you can use mineral oil
with it. BTW Stormy is a idiot posing as a hvac tech as his remark
about using a low temp ref shows. R-22 is not typically used in a low
temp applications. It can be used as such but it has special needs
when its used in low temp apps. Your application would be considered
high temp. Its all about evap temps not boiling points like the dumb
ass mormon thinks.
Whenever I've used R22 in low temp applications, hell,
even in refrigeration medium temp applications I always
have to have a defrost system. A lot of the Domino's
Pizza stores switched over to R22 in the walk-in coolers
some years back and they all have to have defrost systems.
I have to rebuild one here soon.
On Tue, 28 Jul 2009 15:53:04 -0500, The Daring Dufas
Most of the time med temp ref is off cycle defrost. I suppose Dominos
wants 34 or cooler? as a target temp so a clock might be needed. In a
36-40F box you shouldnt need anything but off cycle lessen it isnt
sized or adjusted right.
The R22 walk-in coolers come from the factory with defrost
timers. In order to get the 33-40 box temps, the evap runs
a lot colder and of course the darn door does not stay shut.
I like to set them at 35 because of all the meat products
they stock and of course it helps keep the food temps where
the health dept likes to see them with the door being open
so much. I have one at a store I service that was an R12
system originally, it's now running on 416a and keeps on
running better than most. It has a three phase semi hermetic
compressor, large receiver and pump down control, it's very
reliable because it was installed CORRECTLY. The crap I
see when some (techs?) throw them in is astounding. Oh darn,
there goes my blood pressure.
On Tue, 28 Jul 2009 22:16:27 -0500, The Daring Dufas
Evaporator temperatures are the same for the application (low - med -
high temp) regardless of what ref is used. R 12 med temp evaps run
at the same temperatures as an R 22 med temp evap. No need for a
defrost clock just because it has R 22 in it. There may be other
reasons for a defrost clock but the type of ref isnt one of them.
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