Refrigerant Leak

Hi all hope everyone enjoyed Christmas and are now well rested.

I've been recently called out to look at a display refrigerator which wasn't cooling. On inspection it was found that the system had lost all of its refrigerant charge. Following a pressure/leak check a 0.2bar pressure loss was recorded over a 24hour period at 25 bar test pressure. Attempts to find the leak have failed and so the customer has asked if I could regas the system just this once due to how small the leak is and if they put plans in place to change the system within a 12 month time period. I say asked they begged as they have no way of keeping their salad chilled and cannot afford a replacement. Having done a little work in the US I know there is allowable losses/ trigger rates meaning systems with small leaks can be charged. However does this apply in the UK? or must I condemn the system.

All advice welcome


Cheers Dave

.

Gray area?
:)

From memory a hermetically sealed system is deemed hermetically sealed
if it leaks less than 3 grammes a year and a leak detector should be capable
of finding leaks smaller than 5 grammes a year.

I do know that using dye to find a leak technically is breaking the law because
somewhere in the requirements you are not allowed to use gas as a trace gas
to find a leak but I have never heard of anyone ever being reported and in trouble
for using dye.

So if you add a small amount of the florescent dye, do a recharge and then return
later to leak test you could argue that you are doing everything in your power to
find the leak.....

Maybe. :D

Rob

.

Hi Rob

So as far as you know in the UK there is no allowable losses. The EPA in the US allow up to 35% of the total system charge to be lost per year for commercial kit. Soon to be reduced to 25% I think. This definitely seems to be a grey area. I can’t find a clear answer in the UK regs. Cheers for your reply ��

.

The wording is in the F-gas documents and I can't be 100% certain
from memory but I'm almost positive that there is not an actual weight
% allowable and it says all leaks must be repaired ASAP.

Rob

.

My under standing is you cannot leave a system with a leak, that would be classed as deliberate venting, same as if you cut the pipes, but in real life we may aspire to zero leakage but it may not be attainable. As Rob says, using leak detect fluid will at least help locate the leak, given you have a salad display i'd say it's 90% on the evap, probably the return bends. If equipment is beyond economical repair then replace?

Hi Kirky

if the system has lost its complete charge and you have not be able to locate the leak then its pointless recharging the system as its only going to loss the refrigerant charge again
and eventally take the compressor out due to no motor cooling
is wilted salad worth risking your 2079
i work on large centrifugal chillers and when i struggle to find leaks i use 10% helium/nitrogen
guarantee you will find the leak

I hear you guys

i just wanted to help them out. Money’s tight out there. Apparently the system hasn’t worked for a long time but they had another one. This one has recently lost its compressor so they’ve decided to try and get the leaking one back up and running. I’ve check the other system out and sure enough compressor down to Earth. Surely the use of the injected dye as a means of leak detection must mean a leaking system can be recharged in this instance. I think I’ll recharge the system inject the dye then hopefully find the leak. That’s the best I can do for them. If I still can’t find the leak then I’ll condemn the system. Thanks for the advise guys I guess I’m just too much of a big softy at heart but your right it’s not worth my 2079 cheers

Evaporator coils are not too expensive if that's where you find the leak best of luck

.

Swap the comp from the leaky one to the other.

Rob

.

Could be leaking out the shrader port if you still got your gauges on you won't see the leak.