r22 conversions

[Trehak01]

What about MO99? Anyone have any insight of this being a better replacement? what are the pros and cons?

[Putte]

Guys,

has anyone used BMP 438 to replace R-22 in any racks? We have a customer here who's considering it. Aside from the 20% loss in capacity are there any other draw backs?

Ummm. I would do it the correct way... Oil change, seal change, txv change, then put 404A or 507 if low or mid, aircon apps 407C, and a tune-in. Ok some dollar extra now, but it's totally worth it in the end.

[Gnarly]

We want to. Trying to convince the customer is another thing.

[Dowadudda]

Jp, I was just asking cause the ones I have been involved with, a total of 3 in my career, not many, 1 in TX, 2 in MI, we did change them.

Its gotta depend on the valve manufacturer. Gotta. I dunno. Curious now. I wanna know why.

I will be finding out this next week.

[Putte]

Well...

Let me put it in this way... A friend of mine was called to a boat, where the system (R22) was leaking like a schweizer cheese. Well anyway. System was empty when he came there. Fixed all leaks, pulled vacuum, and filled'er up with 417A. T'was no success... Freezers didn't hold more than -10degC/14degF, refrigerators was around 13degC/55degF

Why he filled with 417A? In sweden weren't allowed to fill CFC (stop by year 2000) or HCFC (stop by 2004)

Oh... 417A has 30% loss compared to R22

[Icanfixitall]

We are going through 2 store conversions right now. R-22 MT/LT Racks to R-407F

Leak check & fix existing leaks

change oil, AB to POE, it took 2 changes to get well into the POE range with a refractometer reading ( http://www.nucalgon.com/products/oils/oil-refractometer )

next up, recover the R-22, replace all high side ball valves vapor/liquid lines (per customer), replace gaskets, change filter driers liquid/suction/oil...add new R-407F.

tweak all valve, pressure control, & EMS settings.

Leak check

It's a 2-3 day deal

Are you changing every BV in the whole store? Doing a rebuild for each EPR valve as well? What about other valves? Sounds like a cool project to be on!

[StarCat]

I am having very good results with R-417A also known as DuPont MO-59. It can be topped off in an R-22 system and requires no special oil.
I have a white paper duscussing these attributes which prompted me to try it out.
My test machines are golden and the price is decent through Airgas Refrigerants.

MO-99 may be something that is being orchestrated in new systems from high political levels, but my experience with it is not positive. If you carefully read the documentation, it says
[paraphrased] ......do NOT liquid charge the compressor, permanent irreversible damage will occur.
MO-99 does not seem to get along well with any oil, and it will definitely wash the oil right out of the compressor during tightly controlled liquid charging.
Its not impressing me.

Sincerely

[MicahWes]

I am having very good results with R-417A also known as DuPont MO-59. It can be topped off in an R-22 system and requires no special oil.
I have a white paper duscussing these attributes which prompted me to try it out.
My test machines are golden and the price is decent through Airgas Refrigerants.

MO-99 may be something that is being orchestrated in new systems from high political levels, but my experience with it is not positive. If you carefully read the documentation, it says
[paraphrased] ......do NOT liquid charge the compressor, permanent irreversible damage will occur.
MO-99 does not seem to get along well with any oil, and it will definitely wash the oil right out of the compressor during tightly controlled liquid charging.
Its not impressing me.

Sincerely

Don't they all say no liquid charging at suction?

[StarCat]

Controlled liquid charging has been done since the dawn of refrigeration time, and it will definitely continue.

[Deadcool]

I am having very good results with R-417A also known as DuPont MO-59. It can be topped off in an R-22 system and requires no special oil.
I have a white paper duscussing these attributes which prompted me to try it out.
My test machines are golden and the price is decent through Airgas Refrigerants.

MO-99 may be something that is being orchestrated in new systems from high political levels, but my experience with it is not positive. If you carefully read the documentation, it says
[paraphrased] ......do NOT liquid charge the compressor, permanent irreversible damage will occur.
MO-99 does not seem to get along well with any oil, and it will definitely wash the oil right out of the compressor during tightly controlled liquid charging.
Its not impressing me.

Sincerely

I've only seen MO-99 used once, and my boss made the same comment. The sight glass looked "muddy" and he told me it was oil.

[Poodle Head Mikey]

Do you remember when compressors were dual-rated for R-12 & R-502 ? <g>

PHM
------

We have R507 here, but you don't see much of it except for some supermarket chains. R404A is much more common.

Actually, I've been leaning toward using R404A for R22 medium temp conversions...similar to what you're doing with R507. It reminds me of 20-30 years ago when we had compressors dual rated for either R22 or R502 MT.

R407C for A/C work is pretty good, but MO99 (R438A) is fast becoming the flavor of choice because it's quick and easy, but there's no reason R507 (or R404A) won't work for A/C as well.

[icemeister]

Do you remember when compressors were dual-rated for R-12 & R-502 ? <g>

PHM
------

Copeland appears to be heading back to doing that with their new FFAP scroll condensing units which are compatible with R134A, R404A, R22 and R407C:

Copeland FFAP.pdf

[Poodle Head Mikey]

Good - that will save me working out the performance numbers on my own.

As soon as one of my A/C units needs anything I am going to build my next A/C unit to use R-134A.

PHM
------

Copeland appears to be heading back to doing that with their new FFAP scroll condensing units which are compatible with R134A, R404A, R22 and R407C:

Copeland FFAP.pdf

[Capz]

What about MO99? Anyone have any insight of this being a better replacement? what are the pros and cons?

I've converted four systems to R438. Two split systems where I installed new dry charged POE outdoor condensing units to concealed air handlers in attics. Followed best practices, added suction, liquid filters & changed all sch valves. pressured tested with n2 & pulled low vac. Charged to 6F-8F sub-cool. Units working good but it hasn't been super hot yet either. I'll be watching.

The third was a larger 7.5 ton split with a Copeland scroll. This one has been good too. The 4th was on an old Carrier 10ton package unit with worn compressors. Not so good results but it's working. If I had newer compressors, I believe this unit would be working much better.

[EMETH]

Our school district (31st largest out of 16,000 nationwide) began retrofitting a while back. After being warned in '98 about R22 going bye-bye the Facilities Dept kept spec'ing R22 equipment right up until 12 new schools and freshman academies opened in '10 with brand new R22 systems.

Our purchasing department stopped approving R22 purchases when it hit $500, and forced the retrofitting issue. After careful research (and I mean a LOT), R-407C is our de-facto choice due to better capacity match, mass flow rate and lower discharge temps among other superiorities.

Now, when I say 'our' you must realize that our immediate management lacks the resolution to make command decisions and upper management lacks the aptitude. Fortunately, nearly all of our mechanics support this and have no problem with performing a proper retrofit procedure.

In all systems that can be drained or vacuumed of their MO, we are switching to R-407C and POE. Our results have been above our expectations; the systems exhibited exemplary cooling performance and energy consumption characteristics.

All compressor changeouts have the MO replaced with POE before installation and are charged with R-407C; when possible, new and remanufactured compressors are purchased with POE oil charges.

Unfortunately, a couple of people prefer what we refer to as a “drive-by” retrofit requiring mimimal labor on their part other than getting out of the truck and attaching their gauges.

In a couple of these “drive-bys”, new compressors were installed with the MO and R-422D; the recommended addition of 20% POE oil was not followed. Honeywell and Johnstone are pushing this. (Can't wait to see how well the capacity loss is going to go over with the teachers when schools starts this August with 110+ degree heat index).

We have found that in our MO units that can not be easily relieved of the MO charge, MO oil return with R-407C is successfully enhanced with the addition of Supco 88 to thin the MO, in place of the hydrocarbon content in 438A, 422D, etc.

DuPont has acknowledged that the basic reason for the hydrocarbon content in these blends is to thin the MO in an effort to provide a bit of oil return; the more hydrocarbon in the blend, the better thinning of the MO.

Supco 88 is 98%-99% hydrocarbons.

With 'drop-in' refrigerants, ALWAYS read the fine print at the bottom that essentially says “Good luck on that workin for ya!”

[Poodle Head Mikey]

A few weeks ago I spoke with someone who should know and he said their testing showed that as little as 10% POE / 90% MO provided acceptable oil return.

And also: some closed-system makers have been successfully running 407 over MO (zero POE content) without issue. PTAC's and the like.

I have to do some 407C conversions soon so I will have a stock of 407C. So I have been thinking about pulling the R-22 out of the 30 year old Coleman 13 SEER for my 1st floor A/C system and installing 407C without any other changes. Out of the present evap there is a 13" riser to a reverse trap and then the suction line is dead level to the condensing unit. How much of an oil return issue can there Be? <g>

What is the logic behind the +90% POE 'requirement' ?

PHM
-------

Doing the oil changes ahead only makes sense because you know you'll have to do it eventually...unless the store is closing or planning a major remodel. The old standard for POE concentration is still 95%, but that was established way back in the early 1990s when the manufacturers really didn't have a good handle on how much mineral oil could be tolerated in a system. RobY was involved in this at the time and has commented on this numerous times, adding that much higher MO concentrations will work well with HFC refrigerants and that they're shooting for a goal of 50%, so only a single oil change would be needed.



It's been widely discussed that the leaking seal issue is primarily due to their reaction to the presence of R22 (or any blend containing R22), causing them to swell. If the R22 is removed, they'll shrink and start to leak. I think changing seals before changing the gas might be taking a risk, but all I know is they will shrink quickly. I really don't have an idea of how long it takes them to swell up.

So are we mainly talking about shraders and O-rings, or are other types of seals require replacing? IOW, On a typical market refrigerant retrofit, what seals are the main culprits?

[kklobas]

i was at a coss class a couple months ago. had a very smart older tech teaching it. he said while copeland wont "officially" say or recommend it, that yeah- close coupled systems like reach ins etc.... will work with no oil change at all, package ac units etc.... the OFFICIAL copeland recommendation is change to p.o.e. but he said he knows of lots of smaller close coupled systems running great without oil change.....

[jpsmith1cm]

i was at a coss class a couple months ago. had a very smart older tech teaching it. he said while copeland wont "officially" say or recommend it, that yeah- close coupled systems like reach ins etc.... will work with no oil change at all, package ac units etc.... the OFFICIAL copeland recommendation is change to p.o.e. but he said he knows of lots of smaller close coupled systems running great without oil change.....

No different than when we ran 401a and other R-12 retrofits over mineral oil in small, unitary equipment...

[kklobas]

the funny thing is i am still today running into alot of old systems in resteraunts here using 401,409,414 in the same building. i think i am going to try hot shot 2 for all this old r12 stuff left . i do mainly resteraunts, and believe it or not, most here in Idaho still have something that was originally r12. Ever tried hot shot 2?

[Poodle Head Mikey]

I just bought my first Hot Shot 2 cylinder. Years ago I switched from 409 to 414 (Hot Shot One) and found it worked well in everything so I kept using it. R-409 ran head pressure higher than I was ever happy with. R401 is pushing $600. per 30 - so I'm sure not using that.

PHM
------

the funny thing is i am still today running into alot of old systems in resteraunts here using 401,409,414 in the same building. i think i am going to try hot shot 2 for all this old r12 stuff left . i do mainly resteraunts, and believe it or not, most here in Idaho still have something that was originally r12. Ever tried hot shot 2?