leaky cold room evap

[Andy AC]

I had a call to go to a walk in with a monoblock - no gas, pressurised with ofn - huge leak in evap. Only 4-5 months old, so under warranty.
The customer was concerned about a blue slimy substance on the face of the coil, and around the drain connection - small spots here and there.
In this coldroom he keeps some huge cheese blocks/wheels for his deli business, which apparently give off ammonia - really hits you when you walk in. Would the ammonia cause the coil to rot? The return bends all appear to be fine, the leak is deep within the coil block.
Might just be a dodgy coil, or might be caused by the air in the room, your views appriciated.

Andy

[nh3wizard]

If its a copper coil and you smell ammonia I would have to say yes to it causing the rot.

[Toosh]

I had a call to go to a walk in with a monoblock - no gas, pressurised with ofn - huge leak in evap. Only 4-5 months old, so under warranty.
The customer was concerned about a blue slimy substance on the face of the coil, and around the drain connection - small spots here and there.
In this coldroom he keeps some huge cheese blocks/wheels for his deli business, which apparently give off ammonia - really hits you when you walk in. Would the ammonia cause the coil to rot? The return bends all appear to be fine, the leak is deep within the coil block.
Might just be a dodgy coil, or might be caused by the air in the room, your views appriciated.

Andy

Hi Andy Copper and ammonia don`t mix you might have to organize a different coil

Norm

[littleyapper]

did he tell you he was storing cheese if so you are in trouble... if not tell him he will have to go stainless steel coil... the softer the cheese the worse the problem...

[Andy AC]

Thanks for the replys guys, I didn't think it would be a good mix. I had nothing to do with the supply/spec of the thing, because we are on an island, the supplier/manufacturer got the locals in to have a look.
So far I have been told they will supply a new coil, not a complete monoblock what the customer was hoping for
Looks like alternative arrangements for the cheese is needed.

Andy

[chemi-cool]

Hi Andy,

I have written here in the past about this problem, From my long experience there are two solutions:

1. you can order a stainless steel coil for the evaporator.
2. My solution was to disassemble the evaporator and deep it in epoxy paint and put it back together.

The second method is working now for over 5 years without any problems in a few cheese maturing cold rooms.

[Andy AC]

Cheers Chemi, looks like the paint is the way forward. Anyone recommend one?

Andy

[nike123]

Hi Andy,

I have written here in the past about this problem, From my long experience there are two solutions:

1. you can order a stainless steel coil for the evaporator.
2. My solution was to disassemble the evaporator and deep it in epoxy paint and put it back together.

The second method is working now for over 5 years without any problems in a few cheese maturing cold rooms.

Doesn't that affect heat transfer?

[old gas bottle]

not as much as a hole in it ! same old thing,the coils are that thin now there,s no margine for error,wont even last the warrenty period out now. i think there are some decent coatings available now .anyone ?

[littleyapper]

replacing the coil on the monobloc is not the solution i'm afraid...also painting the coil will affect the coil duty .. you can paint a coil before you install but it would have to be upsized to counter act the loss of heat transfer ... stainless your only man...hope i'm not offending any one as i'm new to this ....GREAT SITE THOUGH