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Kool Tech, your method will only work if the air conditions are the same indoors as they are outdoors. As mentioned on page one of this thread, what if it's 70 degrees inside the building and 90 degrees outside? Both temps are going to affect the pressure in the system. Thanks, everyone, for the replies, even the fundamental replies regarding recovery, leak detection/repair, filter/drier replacements, evacuation and recharging.
Turn system off and let the pressure stabilize, then read the pressure of the system is it relating to the PT chart for the Ambient condition? If it is then your good if not then air has entered the system. If the pressure is higher than what it should be then there is most definitely air in the system. If it appears to have air inside of it then the next thing you should do is look for traces of oil along the lines (previous leaks, possible it leaked out before & someone just placed more refrigerant back in within without pulling a vacuum to remove the moisture from the system). If it looks like this is the case, recover the refrigerant into a recovery bottle & then get a vacuum pump to remove the remaining moisture. If it does not pull down the there is a leak present in the system, repair it before going any further. Then pull a vacuum & either place the existing refrigerant from the bottle back in or better yet if funds are not an issue place new refrigerant inside the system. Also do not forget to get an acid test kit & take a sample of either the oil from the compressor by removing it & turning it upside down or getting a sample by the refrigerant from the service port. If acid is present then you will need to treat the oil.
Originally Posted by Redwood650 That's how I determine if the system has junk in it. You can hear the compressor start to become louder, amp draw increases and the head increases and then settles. Redwood you are dead on according to some of the REALLY old timers i and Uncle are acquainted with. The only variation in the trouble shooting process was the industry veterans were using a watt-meter to detect the higher current draw associated with non-condensates.
Originally Posted by jpsmith1cm I agree. Same here. I keep clean gauges and dirty gauges not 22 or 410 gauges. Sent from my SCH-I510 using Tapatalk 2
Originally Posted by Redwood650 Why not? I use one set of gauges/hoses on both types of systems. As long as you use the correct procedure, there is no problem using one set. I agree.
Originally Posted by GeeMikee I,ll agree with catmanacman, further more don't use the same gauge lines on R-22 and 410a. Why not? I use one set of gauges/hoses on both types of systems. As long as you use the correct procedure, there is no problem using one set.
Originally Posted by catmanacman one way is maintenance tech not bleading the 410 from there hoses with the low loss fittings and putting a 60 inch hose full of liquid 410a in a r22 unit I,ll agree with catmanacman, further more don't use the same gauge lines on R-22 and 410a.
Originally Posted by Barrettservices X2. The only way i have ever used is paying very close attention the gauges and the sounds of the compressor. We have a local large company that didn't vacuum 1000's of systems just purged the lines with refer and called it good. The sound of non-cond as it cycles through the compressor is not hard to miss and the gauges will move quite a bit. That's how I determine if the system has junk in it. You can hear the compressor start to become louder, amp draw increases and the head increases and then settles.
There is no such thing as extra virgin olive oil either... Interesting fact picked up from Italy.. Anyways, I would think it can pump four to seven ounces per stroke. I would feed the tube through the "skinny" line...
Oil Originally Posted by SBKold How much oil do you really get out with a pump like that anyway. I'm assuming you cut the suction line and try to snake a tube in their? Never tried it but seems impossible on a scroll. Not enough to fill the frying pan that's for sure... I haven't used either. Only changed oil once, and I dumped it out...
Oil
How much oil do you really get out with a pump like that anyway. I'm assuming you cut the suction line and try to snake a tube in their? Never tried it but seems impossible on a scroll.
Originally Posted by doc havoc I don't disagree with you, however, there are other things that can make P/T not measure accurate. So, detection and evidence of noncondensables prior to going through the recovery, evacuation and recharge process is somewhat desireable. I don't change oil much... The dealer I have been doing work for is far more interested in just replacing stuff anyhow...
Pay at the pump Originally Posted by doc havoc It's not always practical to change the oil. (hermetic compressors with no drain plugs) http://www.bestbuyheatingandaircondi...tegory_Code=C3
Pay at the pump
Originally Posted by aircooled53 It was called VACUUM back in my day, if you have P/T not measure accurate ,recover refrigerant, vacuum, check with micrometer and re-charge, NO more non-condensables I don't disagree with you, however, there are other things that can make P/T not measure accurate. So, detection and evidence of noncondensables prior to going through the recovery, evacuation and recharge process is somewhat desireable.
It was called VACUUM back in my day, if you have P/T not measure accurate ,recover refrigerant, vacuum, check with micrometer and re-charge, NO more non-condensables
Originally Posted by doc havoc Thanks medic, that's exactly what I was looking for. I figured there had to be a way. catman-speaking from experience? Based on the specific details you listed... Just a note, you'll want to verify a liquid seal at the LL service valve when using this method. Easiest way to do that is run it in cooling mode for a few minutes before testing.
Hey medic - this reminds me of the system you were helping me on this summer. It was a txv indoors with a longish lineset all horizontal that would flash in liquid line close to indoor unit. I was sure I had a liquid restriction but it ended up being noncondensibles and the txv had no liquid seal. With the entire charge pumped into condensor it was about 25 psi partial or 10deg over ambiehnt. I'm not sure how much static subcooling it would have shown with the long lines and all. Interesting.
Originally Posted by Joseph'bidness P.s. I keep saying hemoglobin in refrigerant lines would take iron to transport oxygen. Imagine a surfactant lined purge system for non condensable gases? Isn't hemoglobin blood? Why would that be in an HVAC system?
Thanks medic, that's exactly what I was looking for. I figured there had to be a way. catman-speaking from experience? Based on the specific details you listed...
You can run the test from the LL service port, no problem, even with the LL service valve wide open. Look for a SC reading on the static system with fan running of over 2°. You'll know when the liquid in the coil is at ambient temp when your temperature reading has stabilized. Any reading less than 2° SC could possibly be only instrument error, so don't scream noncondensables if your SC reading is above 0° but less than 2°. FWIW, if noncondensables are bad enough to cause noticable performance issues, then you'd really be looking for a static SC reading much higher than 2°. Convert your saturated temps to pressures, and do the math yourself. A 5 or 10 psi noncondensable partial pressure won't typically cause noticable symptoms. It would be best to get them out anyway, even at low amounts, but don't expect that in and of itself to eliminate the problems that you're trying to diagnose. HTH. I've run this test many times. It works.
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