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Originally Posted by Poodle Head Mikey During the project the engineer customer is with me constantly and endlessly either asking questions or telling me things. Plus; we are trading engineering stories of all kinds, discussing higher education, philosophy, and various languages. At some point I get it all together and looking nice so I dump in some refrigerant and fire it up. I notice immediately that the condenser fan is making a sort of clicking noise. So I look at that and ponder/project just what the problem might be. Immediately the guy starts: What's the matter? Is something wrong? What could it be? Why would there be a problem? (and on and on until I want to bellow Shut The Fuk Up! - but don't because I am too gracious) I'm tired, it's hot, he has managed to stand in front of my fan all day, and the yammering is bugging the hell out of me. So I listen and realize that it's the compressor - not the fan making the noise. It sort of sounds somewhat like a scroll running backwards - but this is single phase so it's not that. So then I get him to be quiet and I am frenziedly scanning through the data banks: How can this be? What is that noise? What can cause this? About then I notice that the gauge pressures are almost exactly the same. What??? A brand new compressor isn't pumping? How the hell can that be? So I shut it off again and pause and ponder and go over the details of the install again in my head: running the mental video. It was just about then that I realized that I had neglected to open the service valves on the unit. <g> I laughed and leaped to do that - of course immediately contaminating the R407 with whatever non-condensible the dry pressure charge is. <g> In the end I did manage to get away without drowning - but just Barely. <g> I have seen scroll compressor on single phase running backward. I put it in last week. no pressure difference, but have amp draw and new hard start + cap. ran normally when I switch the common and run lead. speaking of 407: I have several liebert on it, and two split system feeding an HRV on it. don't have the experience to tell what's the advantage from one refrigerant to the other... but I could fix it when it's not working.
Originally Posted by MontanaJon According to my 407c pt chart your vapor pressure temp should be 48º instead of 38. Either yor sh math is wrong or mistype for sp/temp. 3º over ambient with 13º sc. That's got to be the best refrigerant for heat exchange ever...lol Just did a quick calculation I learned in diagnostics class which is 82 degree return temp - 35 which equals 47 degree evaporator saturation temp. Very close to your number MontanaJon.
Oh! I forgot the best part ! During the project the engineer customer is with me constantly and endlessly either asking questions or telling me things. Plus; we are trading engineering stories of all kinds, discussing higher education, philosophy, and various languages. At some point I get it all together and looking nice so I dump in some refrigerant and fire it up. I notice immediately that the condenser fan is making a sort of clicking noise. So I look at that and ponder/project just what the problem might be. Immediately the guy starts: What's the matter? Is something wrong? What could it be? Why would there be a problem? (and on and on until I want to bellow Shut The Fuk Up! - but don't because I am too gracious) I'm tired, it's hot, he has managed to stand in front of my fan all day, and the yammering is bugging the hell out of me. So I listen and realize that it's the compressor - not the fan making the noise. It sort of sounds somewhat like a scroll running backwards - but this is single phase so it's not that. So then I get him to be quiet and I am frenziedly scanning through the data banks: How can this be? What is that noise? What can cause this? About then I notice that the gauge pressures are almost exactly the same. What??? A brand new compressor isn't pumping? How the hell can that be? So I shut it off again and pause and ponder and go over the details of the install again in my head: running the mental video. It was just about then that I realized that I had neglected to open the service valves on the unit. <g> I laughed and leaped to do that - of course immediately contaminating the R407 with whatever non-condensible the dry pressure charge is. <g> In the end I did manage to get away without drowning - but just Barely. <g>
Oh! I forgot the best part !
Originally Posted by Poodle Head Mikey Apparently so. My test gear is accurate. Why do you ask? PHM ------- Cause generally that would indicate a restriction before the schrader valve, or where you have your temp probe. Same thing if you had an R22 system, you wouldn't want or expect your LL temp to be below outdoor temp.
I used a Thermal Zone - made by Rheem they tell me. And after seeing the unit inside and out - if Rheem didn't build it; whoever did made a perfectly replicated job out of it. <g> I have forgotten already - what was the frankenstein-ing of your five ton to consist of? I must have goofed up the start-up numbers in some way as the extremely-picky engineer customer seems thrilled with the system's performance and called me to say so. PHM ------- Originally Posted by Snapperhead I still have not frankensteined my 5 ton unit from couple weeks ago .... i might do what you did depending on your outcome. Did you choose a chinese cond ? ps .... my evap has no leaks
I still have not frankensteined my 5 ton unit from couple weeks ago .... i might do what you did depending on your outcome. Did you choose a chinese cond ? ps .... my evap has no leaks
I guess I have to go there back now <g> I have been puzzling over my notes - scribbled from memory after the fact as the job was a rain-out at the end - and now I'm not even sure whether they came from this 407 job or not! <g> The more I think about it the more confused I get. So I guess I have to run back over there - I'll explain it a a gesture of good will: just want to make sure everything is perfect for you. <g> I won't bother mentioning the real reasons. <g> PHM --------- Originally Posted by Poodle Head Mikey Customer had/has a leaking evap - would not replace a month ago. Customer had a compressor fail - would not replace evap now. I installed an R407 condenser and a huge LL drier This is the result: Outdoor Ambient 82º Indoor Ambient 82º Head press 180 lbs = bubble point 85º Suction press 75 lbs - dew point 38º LL temp 72 Subcooling = 13º Suc temp 66 SSH = 28º Evap air TD - 82º-65º = 17º How does it look to you?
I guess I have to go there back now <g>
Yeah - how can that be? PHM ------ Originally Posted by Poodle Head Mikey Customer had/has a leaking evap - would not replace a month ago. Customer had a compressor fail - would not replace evap now. I installed an R407 condenser and a huge LL drier This is the result: Outdoor Ambient 82º Indoor Ambient 82º Head press 180 lbs = bubble point 85º Suction press 75 lbs - dew point 38º LL temp 72 Subcooling = 13º Suc temp 66 SSH = 28º Evap air TD - 82º-65º = 17º How does it look to you?
According to my 407c pt chart your vapor pressure temp should be 48º instead of 38. Either yor sh math is wrong or mistype for sp/temp. 3º over ambient with 13º sc. That's got to be the best refrigerant for heat exchange ever...lol
Originally Posted by Poodle Head Mikey The coil is original to the house which is 28 years old. 10 SEER would be optimistic I would think. This condenser is OK to use for r22 and r407 - so I would think it would be a standard r22 unit - except with POE oil in the compressor.. PHM ------- bought one today u are correct
Originally Posted by Poodle Head Mikey Apparently so. My test gear is accurate. Why do you ask? PHM ------- Liquid line shouldn't be cooler than the air cooling the condenser unless there's a problem (restriction?) or your temp reading is not accurate for some reason.
Originally Posted by beenthere Your LL temp is 10° cooler then the outdoor temp? same thing im thinking.
The coil is original to the house which is 28 years old. 10 SEER would be optimistic I would think. This condenser is OK to use for r22 and r407 - so I would think it would be a standard r22 unit - except with POE oil in the compressor. PHM ------- Originally Posted by ga-hvac-tech Not picking and poking... If the indoor coil is old (do we know its age), Do we have a SEER rating match between the indoor coil and outdoor unit? If not... then problems may arise. My experience suggests higher SEER evaps work with lower SEER condensers... however higher SEER condensers do not play well with lower SEER evaps... unless the outdoor unit is smaller in tonnage. A TXV probably would help. Just curious... I am not familiar with a 'R407 condenser'... other than a dry unit that has POE oil in it. Is this a refer unit?
Apparently so. My test gear is accurate. Why do you ask? PHM ------- Originally Posted by beenthere Your LL temp is 10° cooler then the outdoor temp?
IMO that's going to bite him in the butt PHM. 407C has a huge glide and can't be topped off. It's going to cost him a small fortune every time you come out because of that leaking coil.
Not picking and poking... If the indoor coil is old (do we know its age), Do we have a SEER rating match between the indoor coil and outdoor unit? If not... then problems may arise. My experience suggests higher SEER evaps work with lower SEER condensers... however higher SEER condensers do not play well with lower SEER evaps... unless the outdoor unit is smaller in tonnage. A TXV probably would help. Just curious... I am not familiar with a 'R407 condenser'... other than a dry unit that has POE oil in it. Is this a refer unit?
Your LL temp is 10° cooler then the outdoor temp?
I don't know - I can't get to the indoor coil. The system was a 28 year old Lennox 5 ton. The evap leaks but the owner has so far refused to replace it. A dry-charged R-22 unit just seemed too stupid so I used a POE unit and charged with 407C. That way he can stay with the refrigerant whenever he comes around to the idea of a new furnace and coil. I was surprised to see the head pressure so low with the 407. At 100º condensing the chart has 407 running about 30 lbs Higher than R22. The conditions seemed more relaxed than I expected. I want to stop by again when the house is at conditions and see how everything looks. PHM ------- Originally Posted by codgy Haven't used it in a/c yet. Several med. temp applications have worked out fine. Those pressures appear ok. Is this txv or orifice system?
Haven't used it in a/c yet. Several med. temp applications have worked out fine. Those pressures appear ok. Is this txv or orifice system?
Anybody using R407 ? Customer had/has a leaking evap - would not replace a month ago. Customer had a compressor fail - would not replace evap now. I installed an R407 condenser and a huge LL drier This is the result: Outdoor Ambient 82º Indoor Ambient 82º Head press 180 lbs = bubble point 85º Suction press 75 lbs - dew point 38º LL temp 72 Subcooling = 13º Suc temp 66 SSH = 28º Evap air TD - 82º-65º = 17º How does it look to you?
Anybody using R407 ?
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