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From the field, on R422B, after a change out from R-22 we did experience the problem with a high superheat as the old SEV-4 TEV's would not provide adequate flow yielding a 24 degree superheat, even when backing the adjustment stem fully out. At Spoland's advice we changed out the SEV-4's for SEV-8's and we able to get a clean 8-10 degree SH.
Thamks for the great info Bunny!

i use MO99 and so far never had a problem
before that, i tried RS44B, was ok, but, in my opinion, was not performing 100%, but i had to deal with it.
now i understand why and Bunny post, thank you Bunny, confirm me that i was right.

Very surprise MO99 look like the best MO related as %

Awsome breakdown Bunny. Do you want to come give a talk to our local RSES chapter monthly educational meeting here in Ks.? Just kidding. Again, great use of facts.

Originally Posted by tvpbnl

I got this directly from Parker/Sporlan:

Tom,
Thank you for the clarification. For R-422B with evaporator temperature of 40 F, condensing temp of 110 F, liquid temp 90 F, and a refrigerant distributor the valve should be the
SVE-8-GA or ERVE-8-GA
Or if you prefer the CP100 charge, then use SVD-8-CP100 or ERVE-8-CP100.

The SVE-4 would be undersized for this application.

See below for results of Virtual Engineer Selection program. This program can be found at
http://solutions.parker.com/sporlanvirtualengineer
Thank you

There's way too much disinformation surrounding R-22 replacements, their performance, what it/isn't acceptable, etc.

The fact is, as someone stated....there are NO drop-ins (as drop-in implies you can remove the R-22, replace it with R-Drop in, and walk away without any further effort). Some of the replacements might perform similarly to R-22 in some aspects, but not in other aspects. Some don't perform similarly to R-22 in any aspects.

The chart below shows some of the popular R-22 replacements, and their performance in an AC application compared to R-22. Note the comparison in (1) capacity compared to R-22, (2) mass flow rate compared to R-22, and (3) efficiency compared to R-22.

Attachment 812262

Capacity is pretty self explanatory. For example, why would one ever consider using R-417A or R-424A with their 14% capacity loss compared to R-22....unless, your distributor is telling you it's the perfect "drop in" for R-22.

R-428A has great capacity compared to R-22, but with an additional 70% mass flow requirement...TEV and distributor replacement guaranteed. Possible piping modifications, solenoid valve replacement, and who knows what the compressor capacity will be. Bad choice.

On paper....the two best choices, from a capacity, mass flow and efficiency comparison, are R-407C and R-427A. In reality, there's another factor to consider: Price and Availability. R-407C is out of patent, and is very widely distributed...and inexpensive. R-427A is under patent, and is less available, and more expensive. One additional comment about R-427A...their literature states that an oil change (to POE) might not be necessary. R-427A does NOT contain hydrocarbon components, which are the components that allow some blends to be used with mineral oil. While you might "get by" using mineral oil in very close coupled systems, this is bad advice...and likely added as a marketing piece to gain sales. Again, don't be fooled by the disinformation.

R-422B has an 11% capacity loss, and an 18% increase in mass flow requirement. That, combined with the different pressure/temperature relationship, will result in a much greater pressure drop across the refrigerant distributor nozzle.

Part of the TEV capacity comes from pressure drop across the TEV port. So, if a greater portion of the total available pressure drop occurs across the distributor nozzle, it means there's less pressure drop available for the TEV...with the resulting drop in TEV capacity.

Below is a properly selected distributor nozzle (#3 orifice) for the 5 ton R-22 system, using the Sporlan selection program. Next, the existing R-22 nozzle is selected for performance with R-422B. What was a reasonable 37 psi pressure drop across the distributor tubes/nozzle with R-22 is now a 60 psi pressure drop with R-422B.

Attachment 812263

Next, take a look at the TEV selection for the existing R-22 system. It appears the 4 ton valve is a little undersized, as it's operating at 113% of rated capacity. It's definitely a curious choice for the original installation. The 5 ton valve is a better selection, and it's operating at 98% of rated capacity.

The same system, utilizing R-422B, requires an 8 ton TEV, and it's operating at 96% of rated capacity. The increased mass flow requirement of R-422B, the higher pressure drop across the existing R-22 distributor, and the resulting lower pressure drop across the TEV (due to the increased distributor pressure drop + the result of the pressure/temperature relationship for R-422B) are the reasons for the existing R-22 TEV being seriously undersized.

Attachment 812264

This is why the term "drop-in" is such an overused, meaningless term. When doing a conversion, it's best to do a complete survey and see what the compressor capacity is with the new refrigerant, see if components such as TEV and/or refrigerant distributor need replacing, and in refrigerants that require significantly more refrigerant mass flow determine whether pipe sizing changes and/or other components will require replacement.

And if Distributor A is the sole agent selling R-###….and they tell you it's the best thing on the market...do some homework to verify whether they are telling you the truth, or simply trying to make a sale.

Final note: There's no issue in mixing mineral oil and POE. There is a lot of field experience with mixed oils in systems without any issue at all.

As further evidence, R-422D was being used as an R-22 replacement in supermarkets some years ago. R-422D is marketed as a blend that can operate with mineral oil...this because of some hydrocarbon additives to the refrigerant. But the reality was, in some applications with long/complex piping runs, there were oil logging issues in evaporators.

Copeland's solution: Add some POE to the system, as the POE will "grab" onto the mineral oil and assist in returning it to the compressor.

Attachment 812267

R427a when mineral oil
R407c Poe oil
Make it simple and label it


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I've done a few retro fits.
But it's not my go to solution.
I've installed r407 condensers
Not my go to solution.
My go-to solution is install a new R410 evaporator and condenser.
It even comes with a manufacturer warranty.

Originally Posted by VTP99

So what's your next course of action ?

We are going to changed out the expansion valves.

United supply, months back, didn't even sell r 22, only nu22.

Need bigger expansion valves with R-422b retrofit

I got this directly from Parker/Sporlan:

Tom,
Thank you for the clarification. For R-422B with evaporator temperature of 40 F, condensing temp of 110 F, liquid temp 90 F, and a refrigerant distributor the valve should be the
SVE-8-GA or ERVE-8-GA
Or if you prefer the CP100 charge, then use SVD-8-CP100 or ERVE-8-CP100.

The SVE-4 would be undersized for this application.

See below for results of Virtual Engineer Selection program. This program can be found at
http://solutions.parker.com/sporlanvirtualengineer
Thank you

Originally Posted by tvpbnl

I recently replaced the R-22 on a 10 ton de-humidification unit with R-422b (NU-22). I did remove the mineral oil from both Copleweld 5 ton compressors, replaced with POE. I felt the NU-22 could handle the residual mineral oil throughout the system. The pressures were very similar to R-22.
The NU-22 has a 10 degree glide. I followed the dew TP chart and with my digital gauges, I was seeing a very high superheat on both system (24 degrees) with a clear sight glass. The system had Sporlan SVE-4-CP100 (4 ton) valves. I ran the adjustment stem all the way out and could get no lower. When I checked with Sporlan they said that R-422b would require SVE-8-CP100 (8 ton)valves to maintain proper refrigerant flow to the evap. I guess if you have a piston expansion device it could be changed out. If you have cap tubes your screwed.
I did change out the Schrader valve cores and service caps.

Please post where it says double the valve size!

I call BS

Originally Posted by tvpbnl

I recently replaced the R-22 on a 10 ton de-humidification unit with R-422b (NU-22). I did remove the mineral oil from both Copleweld 5 ton compressors, replaced with POE. I felt the NU-22 could handle the residual mineral oil throughout the system. The pressures were very similar to R-22.
The NU-22 has a 10 degree glide. I followed the dew TP chart and with my digital gauges, I was seeing a very high superheat on both system (24 degrees) with a clear sight glass. The system had Sporlan SVE-4-CP100 (4 ton) valves. I ran the adjustment stem all the way out and could get no lower. When I checked with Sporlan they said that R-422b would require SVE-8-CP100 (8 ton)valves to maintain proper refrigerant flow to the evap. I guess if you have a piston expansion device it could be changed out. If you have cap tubes your screwed.
I did change out the Schrader valve cores and service caps.

So what's your next course of action ?

I recently replaced the R-22 on a 10 ton de-humidification unit with R-422b (NU-22). I did remove the mineral oil from both Copleweld 5 ton compressors, replaced with POE. I felt the NU-22 could handle the residual mineral oil throughout the system. The pressures were very similar to R-22.
The NU-22 has a 10 degree glide. I followed the dew TP chart and with my digital gauges, I was seeing a very high superheat on both system (24 degrees) with a clear sight glass. The system had Sporlan SVE-4-CP100 (4 ton) valves. I ran the adjustment stem all the way out and could get no lower. When I checked with Sporlan they said that R-422b would require SVE-8-CP100 (8 ton)valves to maintain proper refrigerant flow to the evap. I guess if you have a piston expansion device it could be changed out. If you have cap tubes your screwed.
I did change out the Schrader valve cores and service caps.

Originally Posted by pecmsg

Chillers are a completely different story!

I know, just making a reference that even if the oil is fresh out of a container, there still may be some crap in it.

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Originally Posted by BennyD

Same here, I always pull on fresh oil! I do a bit of chiller work. Even with mineral oil, you should see how much comes out of it when the vacuum gets deep through the sight glass.

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Chillers are a completely different story!

Originally Posted by captaincompressor

I do oil changes before the evac. Oils do mix. Dont believe the hype.

Same here, I always pull on fresh oil! I do a bit of chiller work. Even with mineral oil, you should see how much comes out of it when the vacuum gets deep through the sight glass.

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I do oil changes before the evac. Oils do mix. Dont believe the hype.

Originally Posted by tvpbnl

Yes, POE is very hydroscopic. On this job the unit was open to the atmosphere. New dryers are installed. To minimize the POE coming in contact with moisture, evacuate your system after leak checking. Since we have a measured amount of oil you can break the vacuum by drawing out the oil before adding the new refrigerant.

If you suspect contaminated oil (Haven't run across that a whole hell of a lot) change it before pulling a vacuum. Why open the system after!

Originally Posted by BennyD

Evacuate BEFORE adding the oil?

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Yes, POE is very hydroscopic. On this job the unit was open to the atmosphere. New dryers are installed. To minimize the POE coming in contact with moisture, evacuate your system after leak checking. Since we have a measured amount of oil you can break the vacuum by drawing out the oil before adding the new refrigerant.

Originally Posted by tvpbnl

Yeah, mixing the two oils is not a good idea. The compressors name plate indicate they were charged with 70 oz. of mineral oil. We plan to remove the compressors and measure what we take out of the system. After a nitrogen blow out of the coils and heat exchangers, leak check and evacuation down to a least 250 microns we will then charge with POE based on name plate. The residual mineral trace oil should not be a issue. We will then charge the system with R-422b which can handle some MO.

Evacuate BEFORE adding the oil?

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