Airwell VRF - Bursting Condenser Coils

[Aircon Engineer]

We have recently been asked to look at an Airwell VRF 3 Pipe Installation. Commissioned back in 2008/9. Systems have a history of bursting left hand side condenser coils. There are 10 Outdoor Units and 9 of these have had multiple replacement Condenser Coils replaced over recent years. Indoor Units are Airwell Ducted. Outdoor are Airwell (Sanyo Rebadged)

We recently replaced one of the Outdoor Units with the Sanyo / Panosonic latest model. We monitored all the date for 4 weeks and have had no further problems with bursting coil.

Have any of you Air Conditioning Engineers come across this issue with Airwell 3 Pipe VRF on UK Sites / Installations?

I would be very interested to know of your experiences and any other sites with the same issue. The customer in this case has spent a huge amount of money replacing condenser coils before we became involved.

Any feed back would be greatly appreciated

[Brian_UK]

Do Sanyo have any comments about their product failures?

[JP6]

I assume you've contacted the manufacturer about this?

[Aircon Engineer]

I assume you've contacted the manufacturer about this?

Hi Brian & JP6,

Yes we had Sanyo / Panasonic Engineers up to site prior and during the replacement of Airwell Unit to Panasonic.

They kept their cards close to their chest on the reasons as to why this is happening.

I am interested in hearing from Engineers that have information on other sites in the UK that are experiencing burst left hand coils on Airwell 3 Pipe VRF Outdoor Units?

Establish if there are other sites with the same problem

Any help / information would be greatly appreciated. I am aware of one other site this has been happening.

[Aks32r]

I,
Sorry i can help you but i'm interested to know where is the failure ? In the botom of exchanger , the midle or the top ?
If you have this problem in 9 outdoor unit , the real problem is the final assembly .
Is this installation have brased with nitrogen flow?

[Magoo]

Possibly over expanded tubes during manufacture of condenser coil, could be a control problem where coil is stacked up with sub cooled liquid, which then hydraulics and split tubes, could be super thin walled tube that fails around welding points.
Are there any trends to failures, like same coil section area or anything obvious. Manufacturers use super thin wall pipe to maximise heat transfer for maximum efficiency, which is good on paper but not too flash in the field. thermal movement hot and cold expansion stuff.
Add to the mix is re-cycled copper, never the same characteristics as pure copper pipe.
Re-cycled stuff is harder and less flexible with expansion and contraction versus virgin copper. Been there had that problem on a 500 ish kilowatt air cooled condenser.
magoo

[Aks32r]

Yes magoo ,i' m agree.
When the coil is same a block ice , the tubes are pressed same a hydraulic press and you can see that .
Then it become cracked