Leaks in Multiple Daikin Units

[Wellen Const]

I am a builder and I have a home with multiple Daikin units in it. After several years of operation they have all in a relativly short period of time developed leaks in the cooling coils and the outdoor units. My HVAC guy is saying that they appear to be rotting from the inside out. Speaking with Daikin they think that moisture was present inside the system and this over time has caused acid build up that has caused the leaks. This seems odd to me - my HVAC guys says no way no way no way moisture got inside. If this happend to one unit I could see but all (5) seems like something is up. Note that they are not connected in any way they are all seperate. Does anyone have any idea what my issue is? Has anyone heard of this anyplace else? Any help would be greatly appricaited.

[stufus]

Are you near the coast or an industrial.area? if so the air quality could be the cause.
Get your tech to perform acid tests on each system this will determine the presence of moisture or not as the case may be.However if the systems areleaking there will most likely be moisture in there now.
Cheers
Stu

[The Viking]

It depends on where on the systems the leaks are and what refrigerants the units operate on.

In the good old days we used R12-R22-R502 and these operated with mineral oil but due to environmental concerns we had to start using R407c-R410a and the likes. These new refrigerants needs synthetic oil for the lubrication to work and this is where the problems starts.
The synthetic oil will become acidic as soon as any moisture is present.
In the old days when moisture in the system only would cause temporary blockages by forming ice inside the system we could get away with a lot of sins but nowadays almost clinical working practices are required.

Acidic oil will be transported around the system at high velocity, the effect of it hitting bends almost like sandblasting. With time this will cause pitting inside the pipes that eventually will eat it's way through the copper walls causing minute leaks (Normally found on the outside of sharp bends, like the end of a coil).

Did this happen in your case?
Sorry, but it is now way I could tell sitting here in my comfortable recliner.

Can it be proven/disproved?
If a leaking bend is cut out from the system and the inside of the pipe wall inspected it should be perfectly smooth. Most time these type of leaks occurs you can, with a magnifying glass, see lots of small "craters" that formed on the outermost wall.



.

[Peter_1]

In the good old days we used R12-R22-R502 and these operated with mineral oil but due to environmental concerns we had to start using R407c-R410a and the likes. These new refrigerants needs synthetic oil for the lubrication to work and this is where the problems starts.
The synthetic oil will become acidic as soon as any moisture is present.

....

.

Most modern AC uses PVE oil and the big advantage of this is that this oil doesn't become acid in presence with moisture.

http://www.pag-idemitsu-usa.com/pve_benefits.htm
http://www.achrnews.com/articles/ado...a-applications

[Peter_1]

Where exactly do yuo have the leaks? Bends or in the coil? If on the bends, the soldered side or the bended side?

[The Viking]

Fair comment, but I sort of assumed these systems has been in for a few years and the manufacturers I work with used POE until fairly recently.

Most modern AC uses PVE oil and the big advantage of this is that this oil doesn't become acid in presence with moisture.

[seadanzig]

Daikin in the uk were having quite a few problems with condensers leaking they won't admit to it though. All ranging from single splits to vrv.

[CraigF]

Ive replaced a few coils on daikins of late as ive mentioned before on RE.

[seadanzig]

weve stopped using daikin now. very unreliable craig the tech support for them are pretty shoddy too unless you get the right person

[Jackbill]

If the condenser units are RZQ100 or RZQ125 then it may be the same problems a lot of people on RE have had (including ourselves). Where the soldered passes are (compressor side of coil) and go through the steel frame, there have been leaks found.

Daikin as are not admitting to it but it had been common from about 2006 up to 2009. we have changed about 32 condenser coils. They are fully aware of this problem/

Unfortunately it is hard to identify by just Nitrogen Pressure Testing. Sometimes it can be visually seen as the copper passes appearalmost 'honey glazed' where the oil has leaked on to the hot pipework and baked on. Other times, the only way to prove it is to add UV dye in to the system and leave for a while(few weeks) and retest with a UV torch.

NOTE: DO NOT admit to Daikin the use of UV dye to find the leak as your Warranty WILL be invalidated.

The reason wont leak with Nitrogen is the coil is cold, however under normal operation the Condenser coil heats up and the copper passes will leak.

This may be a possible cause of your troubles IF your units are RZQ100 or RZQ125s.

[seadanzig]

hi jackbill youve had the same problem with daikin they have gone down hill in the 15 years ive been doing this job. daikin is a no no for me now

[SeanB]

Only got one Daikin still running, and it is around 10 years old. Noisy fan bearing, and not worth changing ( the boxes it cools don't complain about the noise) and it will be changed when the compressor finally dies, or the outdoor unit finishes corroding all the remaining fins off ( I am at 9m ASL and 200m from the harbour) and falls apart. Has not used any R22 in those 10 years aside from when it was moved to it's current location.

[leegally1983]

Simply Daikin coils are crap, there is issue with them and like others said they wont admit to them but funny enough they have changed the coils they now supply these ones have bigger holes where the pipe goes through the bracket as what was happening when the pipes were expanding and contracting under opertion the pipes were rubbing on the metal bracking and spliting the pipe. Sure sign way of telling is loads of oil inside your condenser....my opinion stick to Mitsubishi

[install monkey]

found this-
http://www.mediafire.com/view/?p3tclpb47ypcpul