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Thread: r22 conversions

  1. #66
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    Sep 2002
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    11,538
    Is there any amount of suction 'lift' in either system? Do the suction lines run uphill or vertical to any degree?

    PHM
    --------



    Quote Originally Posted by EMETH View Post
    Yes to both; the 10 ton is a heat pump with the big red compressor that is also the accumulator. I think it's called a 'Climatuff'?

    I believe that's about the largest circuit we're going to find that doesn't have any way to remove the MO with removing the compressor.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  2. #67
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    No.

    I assume you are referencing condensing units above air handlers; of about 70 some-odd schools I am personally familiar with, only 2 have such a configuration with units that have no ready means of changing out the MO for POE.

    These units are primarily in the 3 to 4 ton range and only have about 4 to 5 feet of vertical rise to the CU.

    However, if a compressor fails in one of these units the new compressor will have POE.

    To my knowledge, the only CU over AHU unit that has been retrofitted to 407C has an 06D compressor and therefore POE.

    I wanted to retro a couple of high schools this summer and recycle about 3000 pounds of R22 for reuse on our smaller units, but can't get the go-ahead from our fearful leader.

    I will inquire of the other guys about any such systems in the 80 other schools their areas.

  3. #68
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    Sep 2002
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    Thanks EMETH -

    Last week I started doing 407C in place of 22. Most are over POE - but with 22 evaps - but one yesterday is 407C over mineral oil with Supco 88 added.

    My psychrometer had dead batteries when I got it out yesterday so the 'start-up' was mostly seat-of-the-pants. I must have left the fan running in the case. I had planned to go back there today and set up the full-lab of test gear but one thing and another (favors for friends <g>) - and now it's nine thirty P and I am eating my first meal of the day. <g>

    Maybe they will be around tomorrow and I can get the whole report filled out. On this job there is essentially zero suction lift (less than two feet) and the lines are well undersized besides - a 3/4" suction line on a 48,000 BTU system. So there is Plenty of return gas velocity. <g>

    Still; I'm a little edgy over it. I sure hope you're right about the Supco 88 handling the oil return. <g>

    PHM
    --------







    Quote Originally Posted by EMETH View Post
    No.

    I assume you are referencing condensing units above air handlers; of about 70 some-odd schools I am personally familiar with, only 2 have such a configuration with units that have no ready means of changing out the MO for POE.

    These units are primarily in the 3 to 4 ton range and only have about 4 to 5 feet of vertical rise to the CU.

    However, if a compressor fails in one of these units the new compressor will have POE.

    To my knowledge, the only CU over AHU unit that has been retrofitted to 407C has an 06D compressor and therefore POE.

    I wanted to retro a couple of high schools this summer and recycle about 3000 pounds of R22 for reuse on our smaller units, but can't get the go-ahead from our fearful leader.

    I will inquire of the other guys about any such systems in the 80 other schools their areas.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  4. #69
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    Jun 2013
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    Mikey

    I am familiar with one high school that has two 20 ton condensers on the roof of the locker rooms; about 25 to 30 foot lift from air handlers to the condensing units.

    I'm going to talk to the mechanic currently assigned to that school about changing one to 407C with Supco 88.

    I also need to get approval from the energy management personnel to run it for a couple of weeks for a fair test.

    Let you know when changeover is accomplished and keep you up to date on oil return (oil sight glasses in scroll compressors).

  5. #70
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    Mikey

    I got an okay from EM person and performed the retro; just posted a new thread in T2T Chat Commercial on the school unit.

  6. #71
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    up in the hizzy
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    very interesting, although the price of r-22 came down there is still a huge demand for alternative solutions.

  7. #72
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    Quote Originally Posted by valdelocc View Post
    very interesting, although the price of r-22 came down there is still a huge demand for alternative solutions.

    Price won't STAY down.

    It'll increase steadily as government imposes more taxes, restrictions and suchlike on it.

    22 is as dead as 12 is.

  8. #73
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    Quote Originally Posted by jpsmith1cm View Post
    Price won't STAY down.

    It'll increase steadily as government imposes more taxes, restrictions and suchlike on it.

    22 is as dead as 12 is.
    True.

    Interestingly enough, one of the DuPont reps revealed that the rise in purchases of substitutes is attributing to the decrease in the purchasing and price of 22.

  9. #74
    Join Date
    May 2003
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    The rise in use of R-22 replacements is not related to the decrease in R-22 pricing. It's a simple supply/demand issue, and look no further than the EPA for the reason why.

    In January the EPA came out with a 2013 temporary allocation for R-22 at 39 million lbs. They came out with their permanent allocation in April at 62 million lbs. This amounts to an approximate 60% increase in supply almost overnight. Yes, there is a little more R-22 available because of the conversions that are taking place, but this is completely dwarfed by the increase in allocation.

    So, yes, the price has gone down a little, but consider this a temporary stay of execution....maybe for 2 years. But the supply is continuing to come down, and will be at ZERO in 2020....so the price will continue to go up, despite this temporary blip down.

    Regarding the seal issue: Only elastomer(neoprene) seals need be changed. There are several issues, but the main issue is the swell issue. Neoprene will swell when in the presence of any refrigerant, but R-22 causes the greatest swell. So, when converting from R-22 to another refrigerant, the % of swell will decrease....effectively resulting in seal shrinkage.

    Combine this with the fact that (1) the seal is likely old, and has become hardened, and (2) it has taken a compression set based upon the pressure exerted on it by whatever is accomplishing the seal....you end up with a seal that isn't capable of providing a seal any longer.

    Older style Sporlan solenoid valves used a tetra-seal; a square O-ring. These seals have been replaced with Wolverine style seals; a rubberized metal gasket. You can get enclosing tube kits and upgrade the solenoid to the current style seal. While technicians don't typically carry torque wrenches on their trucks, all of the bonnet nuts on solenoid valves have a very specific torque setting. Best practice....don't assume that tightening the seal joint as tight as possible is best.

    SORIT and SORIT-PI valves will require seal changes. A common problem occurring when replacing seals on SORIT valves: the enclosing tube nut for the SORIT pilot has a specific torque rating....9-10 ft-lbs as I recall. If this is over torqued, it will cause a disfigurement to the enclosing tube, changing the normally round inside diameter of the enclosing tube to an elliptical inside diameter.

    The pilot valve is normally open when de-energized. This causes the high pressure pilot vapor to pressurize the piston chamber and close the valve. If the enclosing tube has become deformed from over torqueing, it will restrict free movement of the plunger, causing it to remain in the normally open de-energized position, keeping the valve closed even when the coil is energized. At this point the valve would typically be condemned and replaced (or the pilot assembly replaced), when the failure is simply caused by over torqueing. Loosening the pilot assembly and then retightening it to something close to the 9-10 ft-lb range will normally allow the enclosing tube to revert to its original round shape, and operate properly.

    Heat reclaim valves have O-ring seals in them. The 12D and 16D have body flange O-rings, and the pilot assembly will have an O-ring seal too. Given the labor involved in removing a heat reclaim valve to replace the flange O-ring, there are some SM Chains that have opted to replace the heat reclaim valve rather than put a new O-ring in a 10 year old valve.

    Receiver liquid level indicator gauges typically have an O-ring seal. It's much easier to replace this when the R-22 has been removed, then the next day after discovering it is leaking.

    My recollection is that Wal*Mart was replacing oil and seals prior to removing the R-22. While the seal will still shrink some with the conversion refrigerant, the fact that it's a new seal will alleviate many of the leak issues that are experience in not replacing older seals.

    The question about R-438A: The only reason to use it is to avoid the required oil change. There's no other reason to use it. Why sell your customer on a refrigerant that will result in enormous capacity loss? Even if the compressor rack has reserve capacity (extra compressors not being used), how can you justify to your customer with the increased power bill to run additional compressors to meet the capacity requirement?

    Regarding what the refrigerant companies are saying vs the actual performance: Follow the money trail. If Refrigerant Company A is telling you that their product is the best thing on the market.....well, of course you'd expect that. But that's kinda like asking the fox to guard the hen house. Just sayin'.

  10. #75
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    Quote Originally Posted by bunny View Post
    The rise in use of R-22 replacements is not related to the decrease in R-22 pricing. It's a simple supply/demand issue, and look no further than the EPA for the reason why.

    In January the EPA came out with a 2013 temporary allocation for R-22 at 39 million lbs. They came out with their permanent allocation in April at 62 million lbs. This amounts to an approximate 60% increase in supply almost overnight. Yes, there is a little more R-22 available because of the conversions that are taking place, but this is completely dwarfed by the increase in allocation.

    So, yes, the price has gone down a little, but consider this a temporary stay of execution....maybe for 2 years. But the supply is continuing to come down, and will be at ZERO in 2020....so the price will continue to go up, despite this temporary blip down.

    Regarding the seal issue: Only elastomer(neoprene) seals need be changed. There are several issues, but the main issue is the swell issue. Neoprene will swell when in the presence of any refrigerant, but R-22 causes the greatest swell. So, when converting from R-22 to another refrigerant, the % of swell will decrease....effectively resulting in seal shrinkage.

    Combine this with the fact that (1) the seal is likely old, and has become hardened, and (2) it has taken a compression set based upon the pressure exerted on it by whatever is accomplishing the seal....you end up with a seal that isn't capable of providing a seal any longer.

    Older style Sporlan solenoid valves used a tetra-seal; a square O-ring. These seals have been replaced with Wolverine style seals; a rubberized metal gasket. You can get enclosing tube kits and upgrade the solenoid to the current style seal. While technicians don't typically carry torque wrenches on their trucks, all of the bonnet nuts on solenoid valves have a very specific torque setting. Best practice....don't assume that tightening the seal joint as tight as possible is best.

    SORIT and SORIT-PI valves will require seal changes. A common problem occurring when replacing seals on SORIT valves: the enclosing tube nut for the SORIT pilot has a specific torque rating....9-10 ft-lbs as I recall. If this is over torqued, it will cause a disfigurement to the enclosing tube, changing the normally round inside diameter of the enclosing tube to an elliptical inside diameter.

    The pilot valve is normally open when de-energized. This causes the high pressure pilot vapor to pressurize the piston chamber and close the valve. If the enclosing tube has become deformed from over torqueing, it will restrict free movement of the plunger, causing it to remain in the normally open de-energized position, keeping the valve closed even when the coil is energized. At this point the valve would typically be condemned and replaced (or the pilot assembly replaced), when the failure is simply caused by over torqueing. Loosening the pilot assembly and then retightening it to something close to the 9-10 ft-lb range will normally allow the enclosing tube to revert to its original round shape, and operate properly.

    Heat reclaim valves have O-ring seals in them. The 12D and 16D have body flange O-rings, and the pilot assembly will have an O-ring seal too. Given the labor involved in removing a heat reclaim valve to replace the flange O-ring, there are some SM Chains that have opted to replace the heat reclaim valve rather than put a new O-ring in a 10 year old valve.

    Receiver liquid level indicator gauges typically have an O-ring seal. It's much easier to replace this when the R-22 has been removed, then the next day after discovering it is leaking.

    My recollection is that Wal*Mart was replacing oil and seals prior to removing the R-22. While the seal will still shrink some with the conversion refrigerant, the fact that it's a new seal will alleviate many of the leak issues that are experience in not replacing older seals.

    The question about R-438A: The only reason to use it is to avoid the required oil change. There's no other reason to use it. Why sell your customer on a refrigerant that will result in enormous capacity loss? Even if the compressor rack has reserve capacity (extra compressors not being used), how can you justify to your customer with the increased power bill to run additional compressors to meet the capacity requirement?

    Regarding what the refrigerant companies are saying vs the actual performance: Follow the money trail. If Refrigerant Company A is telling you that their product is the best thing on the market.....well, of course you'd expect that. But that's kinda like asking the fox to guard the hen house. Just sayin'.
    Totally agree.

    I'm only repeating what the DuPont guy claimed when showing graphs of decreasing R22 sales and increasing R-whatever sales.

    And since DuPont will be the only player with 438a they can charge whatever they think the market will bear while they recover their R&D outlays.

    What ticks me off the most is all the !&@$#*% people who are topping off 22 systems with 422d. One reclaimer I talked with last week says he routinely gets cylinders from contractors mixed as much as 60/40 with 22 and 422d.

  11. #76
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    Mikey.

    End of week 3.

    Oil return still optimal, no reduction in levels.

  12. #77
    Join Date
    Sep 2002
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    11,538
    Thanks.

    All of my few experiments are running well so far.

    I just did an R22/R407C conversion yesterday which is only pumping 18K BTU's through a 1 1/8" suction line so the suction gas velocity is very low. The compressor oil is 90% mineral oil, 8% POE, and 2% Supco 88.

    Still running well this morning but I'll see what happens over the next month. <g>

    PHM
    ------



    Quote Originally Posted by EMETH View Post
    Mikey.

    End of week 3.

    Oil return still optimal, no reduction in levels.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  13. #78
    Join Date
    May 2003
    Location
    Utah
    Posts
    689
    The first handful of conversions Wal*Mart did were R-22 to R-404A, add a second oil separator, and no oil change. They worked out fairly well until someone decided the second oil separator was too costly, and decided to forgo it. Then they started having tons of issues.

    Later with R-422D, in spite of the refrigerant manufacturer's claim that the refrigerant could be used with 100% mineral oil, they had several store sites where glass door freezers were logging oil. Adding a few gallons of POE solved the problem.

    Refrigerants that have a small percentage of butane, isobutene or methylbutane are advertised as compatible with mineral oil....with the hydrocarbon added specifically to facilitate oil return. However; Copeland released a bulletin stating that in some applications refrigerants with hydrocarbons may still suffer from oil return problems, and that the addition of 5%-10% POE will eliminate those issues.

    It's obvious that POE does enhance the mineral oil's ability to return to the compressor in HFC systems. There are several contractors that I know of who add 5%-10% POE to hermetic or scroll systems after converting to R-407C, and there have been zero oil issues.

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