Using Dye to help leak testDaikin R407C VRV

[garyjh24]

Hello Everybody,

Looking for some advice. I have a Daikin VRV, Model No. RSXYP10L7W1 , R407C.

My question is, this unit has had a tiny leak for a long time, the previous company that maintained the system have recharged it twice over 2.5years. We have had the contract for just over a year now and the system is short again.

Having never used dye before my question is, is it acceptable to use dye on such a system?

Also I have spoken with BOC and they have a Nitrogen/helium mixture, would you recommend using this to pressure test the system?

Look forward to your replies

[hyperion]

Try the dye first, but if the system has lost some of its gas charge and not operating at full efficiency, you are not going to know how much it has lost until you have recovered it. There are different opinons as to whether it is satisfactory to top up or use a completely new R407C refrigerant charge.
By this time you have an empty system and the dye will not serve any purpose until it has been circulating with the refrigerant for a period of time.
Whilst the system is empty, it would be the best opportunity to carry out a full pressure leak test either with nitrogen or helium/nitrogen mix. You will need some means of identifying the leak.
The whole process could be quite time consuming and likewise costly to your client, particularly if the leak proves to be difficult to find.
If you have refnet joints, closely inspect all of these as we have known these to develop small leaks due to expansion and contraction. Hope this helps.

[VRVIII]

Hello Everybody,

Looking for some advice. I have a Daikin VRV, Model No. RSXYP10L7W1 , R407C.

My question is, this unit has had a tiny leak for a long time, the previous company that maintained the system have recharged it twice over 2.5years. We have had the contract for just over a year now and the system is short again.

Having never used dye before my question is, is it acceptable to use dye on such a system?

Also I have spoken with BOC and they have a Nitrogen/helium mixture, would you recommend using this to pressure test the system?

Look forward to your replies
Hi Gary,

Daikin specify dye must not be added to their systems and will invalidate any warranty claims.
The dye can cause problems with expansion valves, I believe Carrier also specify something similar due to problems encountered after dye was added.

If you are trying to locate a very small leak I would suggest isolating the outdoor to narrow the search. If the leak is on the indoor side, I would first leak check all flare connection and indoor EEV’s as these are more common for very small leaks.

[Tony]

I would suggest you do not put dye in.

Try the OFN/Helium mix. Helium has very small molecules, so will find even tiny leaks.

[frank]

As the system is on R407C I would think that it is well out of warranty period now, so I would go with the dye if you can't locate it by any other methods (leak spray, oily deposits, sniffer etc) and you don't want extensive down time to do a recovery and pressure test

[VRVIII]

As the system is on R407C I would think that it is well out of warranty period now, so I would go with the dye if you can't locate it by any other methods

Trust me on this one Frank, it does result in damage to the tip of the EV valve which prevents the valve from closing. This in turn can lead to compressor failures which I have seen a few times, also it’s virtually impossible to remove all the dye from the system after replacing compressor etc.

[james10]

As the system is on R407C I would think that it is well out of warranty period now, so I would go with the dye if you can't locate it by any other methods (leak spray, oily deposits, sniffer etc) and you don't want extensive down time to do a recovery and pressure test
It is no long an option whether or not we recover and pressure test it is Mandatory.:eek:

[multisync]

It is no long an option whether or not we recover and pressure test it is Mandatory.:eek:

Link please