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Robert Wilson
20-05-2010, 02:54 AM
Does anyone have any guidelines for estimating "typical" or "common" ammonia losses in a chiller system. I am trying to determine if top ups every few years correspond to system expansion or continuous leaks. What are some "typical" top up rates for ammonia.

PaulZ
21-05-2010, 07:20 AM
Hi Robert
Every system is different, it depends on how many leaks you have, how many times you have to drain oil, how many times you have to open the system and how well you can pump it out when doing so.

Keep a record of the liquid level in the system and how much you have to add in a given period, 6 months, 1 year, 2 years.

Paul

Segei
21-05-2010, 05:34 PM
Does anyone have any guidelines for estimating "typical" or "common" ammonia losses in a chiller system. I am trying to determine if top ups every few years correspond to system expansion or continuous leaks. What are some "typical" top up rates for ammonia.
I think that ammonia systems should not have ammonia losses. Ammonia isn't ***** and you can smell any leak. Major source of ammonia loss is air purger if system operates at vacuum. Otherwise ammonia systems shouldn't lose refrigerant.

Robert Wilson
21-05-2010, 08:50 PM
Thanks Segei,

Yes, ammonia systems shouldn't have leaks or losses, but they do. I am trying to confirm if our measured loss rate of approximately 3% of system volume per year is "typical" or abnormal. I have seen one other post elsewhere on this forum that described a loss rate of 2.5% per year, over 10 years.

Segei
24-05-2010, 11:58 PM
Thanks Segei,

Yes, ammonia systems shouldn't have leaks or losses, but they do. I am trying to confirm if our measured loss rate of approximately 3% of system volume per year is "typical" or abnormal. I have seen one other post elsewhere on this forum that described a loss rate of 2.5% per year, over 10 years.
Does your system operate at vacuum? Do you have air purger?

Magoo
25-05-2010, 04:39 AM
How long is a piece of string.

brian_chapin
25-05-2010, 12:14 PM
One of my systems operates in a vacuum and I think anything over 1% loss per year would denote something wrong.

Is it possible that you have excessive purging from low side leaks into the system? Could the purger be malfunctioning?

On of my high temp systems has run 14 years without adding any ammonia at all and we haven't seen a drop in receiver levels.

Robert Wilson
08-06-2010, 03:40 AM
Well thanks to those of you that provided some useful information, or at least tried. I don't know if the system is a vacuum system or has an air purger- it's not my system and that doesn't really matter to me- I'm only interested in benchmarking the ammonia losses. From the replies and other forums, it would appear that less than 1% annual system loss should be expected or tolerated, and that more than that should indicate a problem. The system I'm looking at seems to have about 3% annual loss per year (average), but it may be that the "top ups", several hundred pounds every few years, may in fact be due to system changes and maintenance (replacing purged portions of the system, expansion/re-piping), and not actual losses.