Ultrasonic leak detectors

[BNME8EZ]

Anyone use an ultrasonic leak detector? I have a pesky leak that is large enough it should be easy to find, {16 lb in 2 weeks} yet nothing shows. Right now we have 325# of 410a and nitro in it with the service valves closed to isolate inside or outside. We have Inficon leak detectors that usually are to sensitive as you get close to a coil with a leak and it just screams before you can isolate if it is one big or several small.

anyway thinking about a ultrasonic but have never used one before. what are the pros and cons?

[hvacrmedic]

Anyone use an ultrasonic leak detector? I have a pesky leak that is large enough it should be easy to find, {16 lb in 2 weeks} yet nothing shows. Right now we have 325# of 410a and nitro in it with the service valves closed to isolate inside or outside. We have Inficon leak detectors that usually are to sensitive as you get close to a coil with a leak and it just screams before you can isolate if it is one big or several small.

anyway thinking about a ultrasonic but have never used one before. what are the pros and cons?

They're great. There's a learning curve though. The best way to learn the ins and outs is to leave it in the van until you find a leak on some job by other means. Then get out the ultrasonic and pay attention to what you hear, try out the different settings and attachments, see which configuration works best on that leak, or IOW, which configuration really makes the leak noise stand out. Spray some water on the leak and take note of that sound. It's a very distincive sound, and wetting the area will help you locate multiple microscopic leaks along he tube sheet.
j
There are some sources of ambient noise that will render the ultrasonic useless, such as florescent lights for one, and people walking near you, or shuffling their feet. You'll get the hang of it quickly enough, and when you do you'll love the ultrasonic.

I have the Amprobe model, no complaints. Almost forgot, get some quality over-the-ear headphones to use with it.

[coldjoe]

Yes also have one ,great if you can silence the area your looking,mighty in plant rooms power everything down and youll find the tiniest leaks .

[hugogallagher]

Hi You need an EP500 or EP2400 ultrasonic leak detector set. Both these units work in noisy environments.

Go to www.logis-tech-assoc.co.uk or www.logis-tech.co.uk for more details

[itsiceman]

The inficon I/R has a feature where you can disable the auto zero that might help with pinpointing that leak if that is the one you have. Otherwise a ultrasonic should pick that leak up no problem.

[valdelocc]

The inficon I/R has a feature where you can disable the auto zero that might help with pinpointing that leak if that is the one you have. Otherwise a ultrasonic should pick that leak up no problem.

Seriously, are you getting paid by inficon? cause their leak detectors including ultrasonics are the biggest pieces of crap I ever tried.

[itsiceman]

I/R detectors suck balls IMO
If he has that one it is the only one I know of that has that feature.
Why not give it a shot?

[darctangent]

I have the CTRL 101. lots and lots of attachments depending on what you want to do with it. It works and it is HIGHLY directional.


I also have the D-TEK Select. S'ok. I like my H-10PM better. That is one spooky good leak detector.

If I were you I would soak the whole coil in Big Blu, see what pops! Besides that, I wonder why you are still screwing around with a coil that leaks that bad! sounds like you have already spent enough to cover the cost of the coil replacement.

[itsiceman]

I have an ultrasonic made by AccuTrak
Haven't heard many good things here about the Wisper

[darctangent]

I have the CTRL 101. lots and lots of attachments depending on what you want to do with it. It works and it is HIGHLY directional.

I guess I should explain that the CTRL 101 is an ultrasonic detector for leaks and other high frequency sound.

[hugogallagher]

The EP2400 Ultrasonic leak stethoscope detector set should do your job

[BNME8EZ]

I wonder why you are still screwing around with a coil that leaks that bad! sounds like you have already spent enough to cover the cost of the coil replacement.

This is a warranty replacement for a unit that had multiple compressor failures. When the manufacturer replaced it it was upgraded to R-410a outside with a new coil inside. the unit holds 11lb. In 2 weeks it was not flat but low enough it would not run. We found one small leak on the inside coil where the txv equalizer line attaches. the leak there didn't seem to be big enough for that much loss. If we claim a bad coil and it's not we get to eat it. I'm not that hungry yet.

Update: We left at 4:45 pm tuesdayservice valves closed, 330 lb pressure 410/nitro in the system before we closed the valves. Went back Friday 8:30 am 340 in lines and evap, 305 in condenser. Pressure differance within range can be explained by temp difference. left valves closed, dumped the pressure, pulled a vacuum down to 290 microns, it held below 500 for a minute, should be good right. Moved the gauges to constant ports in the heat pump, did the same thing, could only pull down to mid 700's, blank off the pump and in less than a minute it's 3000. Looks like it's outside but can't find anything. Even borrowed a ultrasonic from a friend and nothing.

Thoughts welcome.

[darctangent]

This is a warranty replacement for a unit that had multiple compressor failures. When the manufacturer replaced it it was upgraded to R-410a outside with a new coil inside. the unit holds 11lb. In 2 weeks it was not flat but low enough it would not run. We found one small leak on the inside coil where the txv equalizer line attaches. the leak there didn't seem to be big enough for that much loss. If we claim a bad coil and it's not we get to eat it. I'm not that hungry yet.

Update: We left at 4:45 pm tuesdayservice valves closed, 330 lb pressure 410/nitro in the system before we closed the valves. Went back Friday 8:30 am 340 in lines and evap, 305 in condenser. Pressure differance within range can be explained by temp difference. left valves closed, dumped the pressure, pulled a vacuum down to 290 microns, it held below 500 for a minute, should be good right. Moved the gauges to constant ports in the heat pump, did the same thing, could only pull down to mid 700's, blank off the pump and in less than a minute it's 3000. Looks like it's outside but can't find anything. Even borrowed a ultrasonic from a friend and nothing.

Thoughts welcome.

OK.

I will assume that the leaks are a new development (after the Condenser/Evap replacement)

Considering the seriousness of the customers experience I will suggest that this should be attacked without delay.

I would also suggest that we move this to the pro forums. After this post please start a thread in the pro section. let me know where.

1) When you return to the site, have your leak detector up and reading before you do anything else- no pressure check, nothing before you check with the leak detector. Check all the refrigerant ports first. If you have a schrader leaking you may be dismissing it as refrigerant from hooking/unhooking the gauges. Also pay special attention to the braze joints, new or old. Field produced first, then factory, then everything else. I have found leaks in the middle of bare pipe. no particualy reason, the damn thing just decided to leak.

2) I would suggest separating the condenser and the Evap from the lineset. Pull the evaporator. Cap & pressure test the evaporator and condenser. I'm concerned that you are over pressurizing the condenser in particular. if you boost the pressure that high again you need to make sure that you raise the pressure slowly, and equally to the low and high side of the system. I would also use 22 as the trace gas. pressure test the lineset too if you like.

3) after pressurizing the system, soak both components (condenser and evap) in Big Blu. Big Blu has much better surface tension and will be more prone to show leaks. I don't know of a better leak indicator solution on the market.


NOTES:
As too the leak. It's obvious that you have one, but not so obvious where it is. You need to: 1)suspect everything, assume nothing. schraders, king valves, lineset, factory brazes, bare pipe, the compressor itself. Ignore nothing that the refrigerant passes through. some leaks are temperature dependent. the evaporator is a classic for that. It will leak like a sieve when it has a gas furnace heating, not so much when room temperature.

To the compressor failure- is there a pattern of rotor lock, or are these burnt windings? have you tested for moisture/acid? is this an oil return issue? was there an autopsy on that compressor?

Don't ignore the value of fresh eyes on the system. If you can't do that, you need to open up to new possibilities because however uncomfortable it is, this system has some problems and they need to be found.

On Ultrasonic leak detectors. Others have had different experiences, but mine is HIGHLY directional. my point is the detector needs a direct line of sight or you get squat. if you use it, you need experience with it. The good thing about them is that when you do find a leak, there's no mistaking it if you are experienced. The other thing to know is that the bubble test amplifies the response of the ultrasonic leak detector x10.

[phinncraft]

i have used ultrasonic testing tool for about 6 years now and i find they do work if you know there limits.i find if there is not a lot of wind like on a roof top they are very good.i do fall back on my old mars 120 volt tester they seem to work the best for me on large chillers.i also use ulta sound tools to check gpm in pipes www.reliatools.com