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multisync
22-11-2008, 12:47 PM
Got an old R22 VRV system where the oil is now showing up as 'marginal' on an ATK.

Changing the oil is trickier than not so wonder if there is a suitable HP drier which can remove sufficient acid as an easy fix.We have a std Liquid line 2-way 1/2" Sporlan in for a few months but that's made no difference..We also put in one of those small 'acid away' bottles.



Multisync
london

Thermatech
22-11-2008, 01:24 PM
99% of the oil is returned to the compressor suction by the oil seperator.

For acid clean up I have found the best procedure is to install a shell & core filter drier in the compressor suction between the oil return line & the compressor.
That way all the oil has to go through the burn out filter drier as it returns to the compressor in the suction line.

However it is a big job & costs lots.
You also have to be imaginative with pipe layout & installation.

But have suggested this many times over the years & always works after changing out the core filter drier a few times.

For work on the outdoor unit you can pump most of the refrigerant out of the outdoor unit into the system & then shut service valves & recover whats left.
Man & mate can do this shell & core filter drier retro fit in a long day so long as they know what they are doing.

Sorry its not the easy fix you are looking for but it does work.

multisync
23-11-2008, 03:49 PM
Quicker/easier /cheaper just to replace the oil. That will thin down the acid mix.

In that case what oil do Daikin use on their old VRV R22 stuff.

Can any old mineral oil do?

Multisync
London

Thermatech
23-11-2008, 04:15 PM
Acid can be caused by moisture & after about 2000 hrs operation the moisture becomes saturated in the oil.

So you might also be getting rid of the moisture by replacing the oil depending on when the moisture got into the system.

But some contaminated oil will always get left behind which will then contaminate the new oil again.
The burn out filter drier completely removes the acid.

Assume you will drain down using the oil balance tube & recharge new oil via same.

brunstar
23-11-2008, 10:17 PM
it is mineral oil and if you contact spare parts you can get it from them otherwise it is mineral but not sure of the thickness, technical can tell you if you call them but i would be replacing the oil..if the compressors aren't already damaged.

multisync
24-11-2008, 01:39 PM
Spoke to someone about this and they recommended 'acid away' or an oil change.The oil is pretty std stuff so I will price for it and let the customer know

Multisync
London

Thermatech
24-11-2008, 01:48 PM
I think you will find that 'acid away' converts the acid into cristals which could potentially bock up LEV valve strainers.
So filter driers need to be used also to filter out the cristals

multisync
24-11-2008, 02:15 PM
I think you will find that 'acid away' converts the acid into cristals which could potentially bock up LEV valve strainers.
So filter driers need to be used also to filter out the cristals

The guy said they'd used acid away on many other VRV systems such as this and not had problems. There is a drier on the system already fitted. There was only one pot added so hopefully won't cause too much harm

Multisync
London