Nu-22B (R-422B): Drop-In R22 replacement

[mytekcontrols]

I came across this today NU-22B Literature, and it looks promising for R22 replacement.

Composed of:

• 55% HFC-125
• 42% HFC-134a
• 3% Isobutane (HC-600a)

The literature goes on to further state that this drop-in R22 substitute is fully compatible with Mineral, AB, and POE oils, and that it is nonflammable to boot. So basically no oil substitution is required.

This ability to work with any oil, is made possible by the Isobutane part of the blend. I found it most interesting that such a small percentage of this component could make it work even with mineral oil. Of course keeping the percentage of Isobutane low, makes the overall blend nonflammable as well.

Could be a nice way to go in the first stage of a cascade, or even as part of the mixture for an autocascade. Of course it would also work well in a single stage unit.

[Kepons]

It's very similiar with some other drop-ins. They also contain some hydrocarbons in order to make them work with different oil. Many people hera at XS mix R404a/507 with propane/isobatane to make it work with mineral oil

[mytekcontrols]

It's very similiar with some other drop-ins. They also contain some hydrocarbons in order to make them work with different oil.

Yep I also found another one with a similar blend, only it uses R600 instead of R600a. It's called ISCEON MO59 (R-417A).

Composed of:

• 46.6% HFC-125
• 50% HFC-134a
• 3.4% Nbutane (HC-600)

There is very good article on R-417A vs. R22 called: Use of R417A (ISCEON® 59) in Refrigeration and Air Conditioning Applications, where it compares it in a real application to R22. Although it ran an ever so slightly warmer evap temperature, it's COP was better, probably due in large part to having a much lower discharge temperature.

Once again the oil return issue was handled by a very small percentage of HC, and resulted in a classification of non-flammability for the blend.

[Moc]

Could be a nice way to go in the first stage of a cascade, or even as part of the mixture for an autocascade. Of course it would also work well in a single stage unit.

I don't think people will use it because here in Germany it's quite expensiv in comparison with R404A/R507 and I don't think it's better for low temp application.

[ruffus]

no i just think it is to replace r22 as the are trying to phase it out

[tiborrr]

R-417A is also quite expensive here:

5081XX7610 - FREON R-417 A 12,0 Kg ISCEON 59 ....... 36,96 EUR + 20% DDV tax

~ 44€ per kg. Note that R-22 is around 5€ per kg.

[S-10]

I designed the S-10 technology (AKA Telemark TVP) system. The extensive work we have done in Stratox with various substitutes shows that there is no viable drop in solution for the PFC.

However we have had a great deal of success with non-infringing HCFC blends providing the compressor oil is changed to a Polyol Ester (POE) oil. The protocol is well established in other areas and Carlyle publish a guide to the oil types to be used.

When changing the gas or refilling I would recommend strongly fitting a dual Temprite 905 coalescent oil separator before the condenser as well as the usual filter drier.

This will improve efficiency and also lengthen the life of the PFC, as any one who has worked on these systems they are not that reliable and very prone to oil migration.

Incidentally S-10 / Telemark system has multiple coalescent filters fitted in the array and it doesn't have this particular issue. There are others but that's for them to work out.

I came across this today NU-22B Literature, and it looks promising for R22 replacement.

Composed of:

• 55% HFC-125
• 42% HFC-134a
• 3% Isobutane (HC-600a)

The literature goes on to further state that this drop-in R22 substitute is fully compatible with Mineral, AB, and POE oils, and that it is nonflammable to boot. So basically no oil substitution is required.

This ability to work with any oil, is made possible by the Isobutane part of the blend. I found it most interesting that such a small percentage of this component could make it work even with mineral oil. Of course keeping the percentage of Isobutane low, makes the overall blend nonflammable as well.

Could be a nice way to go in the first stage of a cascade, or even as part of the mixture for an autocascade. Of course it would also work well in a single stage unit.

[mytekcontrols]

S-10 glad to meet you. I guess you could say that I am your Polycold counterpart, and was involved with much of the early design work on the P-20, P-50, PGC-150, and PFC-1000 series units. Presently I contract my services out to a Polycold Service Company called M&T Systems. I also worked with David Fyfe for many years at Polycold, and have touched bases with him occasionally since his move to Telemark.

Yes I finally had to conceed that there was no "drop-in" solution for the non-HFC charged Polycold units that would meet the present day European requirements (no CFCs or HCFCs), and that wasn't extremely flammable. And I also agree with the unreliability aspect of the older Polycolds to properly return oil back to the compressor. This continued problem stemmed from the original owners desire and mandate that the autocascade as designed was all that was required to return the oil. It wasn't until after he was gone that the coalescing oil separators really started to play a role in the oil management aspect of Polycolds.

At M&T Systems we put together a Dual Series-Connected Oil Separator package for retrofit into the PFC-1000 thru PFC-1100 series. This along with some other changes, has greatly increased the reliability of these units.

I am most interested in what you call a "non-infringing HCFC blend". I presume you actually meant to say HFC not HCFC. Can you discuss what refrigerants were used in this blend?

Edit: The only charges that were Patented, were the pure HFC blend, and a non-22 blend that still used HCFCs (R-123 & R124). The non-22 patented blend is only good for use in the non-European market.