Where did the refrigerant go?

[Sub0]

I have a customer who has a large back bar, about 9 evap coils on the system. We got a call its warm. I go check it out, and it has no refrigerant in system. Im thinking, this will be a easy leak find. I dump some gas in it and check for leaks, on all coils,TEV, sol etc. None found. I charge up the unit, 28lbs of refrigerant. So now its got me nervous. Only place I could not check was in the attic. This was 3 days ago, and it has not lost any refrigerant. The system has high and low pressure controls. Its got me baffled because I never ran into a completely empty system and no sign of leaks. No gas = big leak. It was working good, then bam, its warm, over night. At this point im thinking the one man company owner from the other company let it out? Its got me confused. Thoughts??

[markettech]

What was your final micron reading before you charged the sytem back up?

[ON-CALL]

Next time if you come across a flat system get nitrogen with some trase of 22in the system and get up to 150psi you will hear it even in attic.And unless some sees someone letting gas out of the system lets not ASSuME because next time someone could ASSuME that you did something like that.

[Sub0]

What was your final micron reading before you charged the sytem back up?

Oh yea, 440. It was going to be 4 hours till opening an cooler was @ 85 deg.
Was in a hurry.I figured for sure by morning it would be out again, so that early evening I went back to check on it and it was still full. 3 days later, still full.
I will be able to get in the first of next week. There is also plenty of dye in the system.

This is a recent customer and first time I worked on it. He said every few months this happens. No warning signs from cold to warm and the guy keeps coming back dumping refrigerant in it.

Is whats got me so confused is, 0 refrigerant with pressure controls, low pressure control set at 20 psi. A leak that leaks it all out in less then 24 hours is huge.

[Sub0]

Next time if you come across a flat system get nitrogen with some trase of 22in the system and get up to 150psi you will hear it even in attic.And unless some sees someone letting gas out of the system lets not ASSuME because next time someone could ASSuME that you did something like that.

Yea excellent point and good advice. I was sure I would hear it while I was adding refrigerant. Then again, the attic is huge and I need a 20ft step later to get to the entrance which was locked.

[markettech]

Oh yea, 440. It was going to be 4 hours till opening an cooler was @ 85 deg.
Was in a hurry.I figured for sure by morning it would be out again, so that early evening I went back to check on it and it was still full. 3 days later, still full.
I will be able to get in the first of next week. There is also plenty of dye in the system.

This is a recent customer and first time I worked on it. He said every few months this happens. No warning signs from cold to warm and the guy keeps coming back dumping refrigerant in it.

Is whats got me so confused is, 0 refrigerant with pressure controls, low pressure control set at 20 psi. A leak that leaks it all out in less then 24 hours is huge.

Hmmm........sumthin sounds fishy here.

What kind of 1/4" access caps does the unit have - rubber o-ring that are usually hand tight or hex?

[Sub0]

Hmmm........sumthin sounds fishy here.

What kind of 1/4" access caps does the unit have - rubber o-ring that are usually hand tight or hex?

Hand tight with or rings, no hex.

[markettech]

Hand tight with or rings, no hex.

If you pulled 400 microns there is no leak..........period.

That leaves only 2 things that I can think of off the top of my head that would relieve the pressure on the system

The first is a relief valve that is popping and resetting - although those will typically reset well above 0 psig

The second is some knucklehead(s) huffing refrigerant to get high - although you think you'd see a dead body or 2 laying around after 30 lbs of inhaled refrigerant in their lungs.

[Dallas Duster]

Does it have somekind of pressure relief on the system?

[Sub0]

Does it have somekind of pressure relief on the system?

If it does it is in the attic or between the walls. I did not see any. I inspected every line I could get too. I cant wait to get in the attic, its bugging the hell out of me.

[captinsano]

A low micron reading is good but it could be something that holds in a vacuum but not under pressure,so a micron reading is not all I would use.

[Airmechanical]

locking refrigerant caps would be a start

system with no freon=get the nitrogen

tie a balloon on to the relief valve, it will pop the balloon if it dumps the charge



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