How to change oil in a rotary compressor?

Got to love the environmental people. How they protect us from problems that aren't really a problem.

Did'nt think of anything else than R407C before I started to empty it from oil since the compressor is designed for R22 and 407 is wery close ()and I can get 407 wery cheap...

/Lars S

Stormy Mormy would put compressed air from his local service station in it, if it were free.

Could be wrong but looks like a scroll compressor to me. If a scroll compressor is considered a rotary compressor then any rotating pump/compressor could be considered rotary.

The OP stated an oil change in an rotary air conditioner compressor. The rotary screw type normally are filled with oil. Is the scroll type or the youtube link type filled with oil?

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.

TDD

I've seen R-22 in medium temp coolers, several times. Worked on a few, too.

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

Comfort cooling isnt med temp. Youre off topic.

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.

TDD

That would work for a vortex system.

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.

I have a few beore I leave so heres my parting thoughts on your defrost problem. I use a 6F differential on the control setting. So with a 35F box cut out air temp would be 32F and cut in temp would be

I'd bump the temp up a half a degree or so to keep the air temps above

From what I have read the last days on the Internet it could be so that also the lower part of the compressor is connected to the HP side thanks to the oil pump (a hollow main axle). Draining oil from the suction pipe may not be possible since the suction pipe seems to be directely connected to the compressor chamber intake. Drilling a small hole also in the bottom part ("sump") could be the way to empty the compressor from oil.

/Lars S

Since I'm not the worlds leading expert on refrigeration/HVAC, I can only comment on my own personal experience with the various equipment over the last four decades. I would have to research the subject to give you any sort of proper and precise explanation. All I can say is that every R22 walk-in cooler I've ever seen, has had a defrost system except for the homemade ones that didn't work until they were equipped with some sort of defrost system. Every factory built condensing unit for an R22 walk-in cooler including walk-in freezers has had some sort of defrost system. Passive for the coolers, active for the freezers. I'm always willing to learn new things so if you can tell me more and point me to the source, I have no problem being corrected. When it comes to education, my ego doesn't get in the way.

TDD

Every

What do you mean when you say "passive for the coolers"?

I agree every ref system needs some sort of defrost. it could be either electric, hot gas, manual, or off cycle.

What you said was every r22 cooler needs a defrost clock. I don't see why it would. Most refers are designed to have a 2/3 run time. The other 1/3 is off. When it is off the space warms and any light accumulation of frost should melt off before the next start. About the only time I have seen or had to put a timer in is when the customer wants the coldest beer in town and wants the coolers to run

Why is it an r 22 cooler needs a clock when a r 12 cooler didn't. Just askin..

The evap temps are the same for each and every ref used for medium temp work at a 10 delta. The refrigerants pressure/temp relationships change with the type of refrigerant and they all have different boiling points and properties. Some temps are cooler at x pressure and some are warmer. They each have a different capacity per pound circulated and all that jazz but those factors are why there are different ratings for compressor duty and the type of refrigerant used in them.

I hate to type and run but I have to pack the bike now and off to Sturgis. :)

Have fun parking next to 150,000 other bikes just like yours, you rugged individualist, you :-)

Careful out there, the cage drivers are out to get you. Passive defrost: Cut the flow of refrigerant, leave the evaporator fan/fans running. Ambient temp rises melting the frost buildup. Active defrost: Cut the flow of freon, turn off the evaporator fan/fans, turn on electric heaters or use a hot gas defrost cycle to melt the ice buildup. I've never had the R12 systems freeze up unless the temp was set too low or the evaporator air flow was impeded. R22 walk-in coolers always seem to freeze up without a timed defrost cycle. All those years ago when I was at college studying for my degree in rocket surgery, the classes never covered walk-in coolers so I can't give you a scientific explanation.

TDD

You can't do that! This is usenet!