View Full Version : NH3

10-02-2001, 01:00 AM
To answer your question Subzero, yes the pay scale does go up for industral techs. As to your comment about the systems being huge... Some are. For example, a 3 stage system w/ 3 different suction temps, flash cooler vessels, intercoolers, pump packs,liquid over feed & flooded evaps, to more simple systems like a chiller or ice builder.

As to them being like a captube system, no.

I work mostly w/ Frick screw compressors, Frick HDI's & Vilter recips.

My work is mostly w/ dairies, cold storage, food process,& Ice rinks.
The systems I deal w/ are 85% NH3 15% R-22, however I like the NH3 much better.

As to the part about the stink, that is inevitable, however in the famous word of most ammonia techs ... "I don't smell anything" LOL.

Tell me, does anyone else get very hungry after breathing ammonia or is it just me.

Please keep this forum going, as I like trading storys, ideas, & experiences.

[Edited by joscon on 10-02-2001 at 01:09 AM]

10-02-2001, 04:49 PM
Thanks for writing back. I have been looking at possibly changing jobs again... I am really getting tired of corporate crap. I would rather be hands on. Anyway, I have seen quite a few openings for Ammonia Techs but they all seem to want ammonia experience.

I don't mean to sound too outspoken but I am very familiar with refrigeration theories, principles and practice. For sure I haven't worked on everything, one of them being ammonia, but I would not be uneasy with working on it. I love a good challenge really, and I also like the freedom of engineering in the field (that is where the real engineering happens.)

I am thinking of applying in that sector but I am afraid they may take me too lightly and not pay what I need to survive (or my comfort level.) I do quite fair just taking care of the local commercial refrigeration but it is really just a hobby and to keep my hands in service so to speak.

Robert Thwaites
21-02-2001, 01:03 AM
Ammonia is just another refrigerant. There are some major differences. It has an affinity for moisture. Steel pipe not copper. Flamable and sometimes explosive. Forcing a ceased liquid isolation valve and being sprayed with liquid refrigerant can be a little more dangerous than R22. A large high pressure leak can also displace a mechanical room ventilation quite rapidly. I believe any refrigerant can be safe if handled correctly. Don't venture into the ammonia field without a strong appreciation and respect for this gas.

21-02-2001, 11:54 PM
I think this forum is going in the wrong direction.

I don't think anyone thinks ammonia is some exotic refrigerant that requires special training.

The major differences between R-22 & NH3 is that NH3 stinks & the fact that is a much more efficient refrigerant, in other words you would need 6 lbs.or R-22 to do the same work as 1 lb. of NH3.

The smell is the hardest thing to get use to, but work W/ it for a while and you will build a tolerance for it.

With NH3 you must use schd. 80 seamless steel pipe & forged fittings,you can use some aluminum tubing for things like equilizer lines, however I personally do not use it, I perfer all steel.

Ammonia is way more tolerant of H2O then R-22. It is also real inexpensive.

In my opinion, it is the best refrigerant out there.(also the first widely used Refrigerant)

03-03-2001, 03:33 AM
I am quite interested in ammonia systems. I suspect that installations are done simply by people who do only ammonia. Actually, somebody told me that once you get into big piped systems, the iron is cheaper than copper. But regardless, there seems to be a cattleman-and-sheepherder divide between those who work on ammonia and those who work with fluorocarbons.

I have 2 people working for me that enjoy and have experience with ammonia.

Any suggestions regarding how I would approach owners of ammonia plants to get their service and installation business? Is it necessary to develop a specific identity that separates the fluorocarbon identity from a perceived inexpertise with ammonia? Any chance I could use a tech that goes both ways, or should I just have some specializing in ammonia? Some of these questions relate to image and customer acceptance, but they are also questions that ask about how realistic it would be to swing techs between fluorocarbon work and ammonia work. Any thoughts would be appreciated.


Darcy Sergius
24-04-2001, 12:15 AM
I think everyone here is absolutely correct. Ammonia has several advantages and disadvantages, as do many other refrigerants.

It is efficient - correct.
It is hard on the nose - correct as well.

Over the last 19 or so years I have had the opportunity to work with both halogenated halocarbons and NH3. I like both for certain reasons:

1)"HH" (*****) type refrigerants do not require heavy system installations as do NH3. NH3 requires the use of heavy welded steel fittings and pipe. You usually end up tired and very dirty at the end of the day working on an NH3 installation. Copper pipe and fittings are light, easy to fit, cleaner, and do not require a ticketed pressure welder to make gas tight.

2) NH3 is has the ability to carry large amounts of heat energy per pound circulated in a system, thus is deemed as being very efficient. It is ideal for larger systems due to less mechanical horsepower required to do the job.

You will find that some NH3 technicians have an arrogance about them. This may be because they normally work on larger systems. I have never heard of an NH3 man getting paid anymore than his ***** counterpart (Canada). Bigger system = bigger tools = bigger ego...I don't know! Everyone received the same training!!

In conclusion, I like NH3, I like the "HH" refrigerants. There is a place for both in the world which we live. There is also a place for the NH3 guys and the ***** people. One is no better than the other.

Remember NH3 and ***** guys alike...."It is not the size of the tool that counts, it is the way you use it!"

24-04-2001, 12:54 AM

Over the last 19 or so years I have had the opportunity to work with both halogenated halocarbons and NH3. I like both for certain reasons:

Remember NH3 and ***** guys alike...."It is not the size of the tool that counts, it is the way you use it!" [/B]

Question, Darcy. Were you fitted up with the correct tools and safety equipment when you did ammonia jobs? Were you working for a company or did you pretty much choose what you worked on by yourself? Did you or your company bid the jobs and sub out the welding, but did all the heavy lifting?

I guess that was more than a question.:)

24-04-2001, 02:43 AM
I love NH3!! Yes Joscon, I get VERY hungry after breathing vapors, even if I ate a meal recently. Go ahead and shoot for that job Subzero, but expect to experience a learning curve while you become familiar with NH3. As far as your lack of ammonia experience, don't let that stop you. As long as you are willing to prove to your employer that you are very solid with the fundamentals, can troubleshoot well, and do top quality work you should have few problems. You may have to work for a lesser rate until you prove your competence, but it will pay off in the end.

Dan, be aware that with the increased hazards from ammonia comes increased liability. Before you get into doing ammonia service, consult heavily with your insurance provider. As far as getting your foot in the door, I would suggest that if you do not have ammonia experience personally, take one of your techs when meeting the potential customer. The customer can then be assured that your personel have experience with ammonia and not just *****. If the plant calls your company in and there is a mojor screw-up that causes downtime, release, or accident, the person who brought you into the plant is going to be at risk of losing their job. Having been that responsible person for 10 plus years now, I want to be sure that potential contractors truly are qualified. Definately offer a list of references.

I must say how happy I am to have found this forum. I hope to learn all I can and contribute from my meager experience.

24-04-2001, 03:26 AM
Stinky, thank you. Your advice holds weight. I will be asking other questions later.


24-04-2001, 02:18 PM
Oh Great! Just what I need... to get hungry everytime I work on equipment. I just quit smoking about 4 months ago and I have already gained 30 pounds! LOL!!! ~:p~

Darcy Sergius
24-04-2001, 05:46 PM
Originally posted by Dan


Over the last 19 or so years I have had the opportunity to work with both halogenated halocarbons and NH3. I like both for certain reasons:

Remember NH3 and ***** guys alike...."It is not the size of the tool that counts, it is the way you use it!"

Question, Darcy. Were you fitted up with the correct tools and safety equipment when you did ammonia jobs? Were you working for a company or did you pretty much choose what you worked on by yourself? Did you or your company bid the jobs and sub out the welding, but did all the heavy lifting?

I guess that was more than a question.:) [/B]

Yes, we were fitted with all the proper safety gear, tools, etc. I work for a larger, family owned contracting and service company. Sometimes we can pick and choose what type of work we do, but normally we bid on whatever work is out there. We always sub-contract our welders. As refrigeration people in Canada we are deemed as "pipe fitters" so therefore do all the grunt work for the welders.

The point I was trying to make is just because a mechanic works on an ammonia system it does not mean he is "big **** on the block". Yes, ammonia systems are large and tend to be interesting, but they basically operate the same as a ***** system. However, they add a few more bells and whistles to deal with the refrigerant volumes, system tonnage, and load variances.

I like both ***** and ammonia. Just because I have worked on ammonia systems does not mean I sit on a pedastal above my colleges.

Thanks for your comments.

Hlynur Steinarsson
25-06-2001, 10:07 PM
The best refriderant is ammoniak because first of all you always know what is happening in the pipes, not like the new refriderants (R-507, R-404)where for instant the gas pipe is only like 65C. The smell also in good because then you cant have any leaks.

26-06-2001, 05:18 AM
Dang. That smell thing again. Apparently, either one is into ammonia, or out. Why this separation? I can blame half of it on my management. But it still seems there is an insurmountable gap to over come. Yet I have a rare tech or two who is comfortable with ammonia, although not anymore set up to work with it. A closed society, it appears.
I am missing something.

I must get smarter. Keep the good talk up, fellows.


26-06-2001, 07:17 PM
I once worked for a company that specialized in ammonia systems. On my very first job, the system had a substantial leak. It didn't take long to realize that my mask didn't fit very well over my beard.

Choking all the way, I managed to close off the leak. I then returned to the shop, dumped all of the ammonia equipment on the table, and told the boss to find me some ***** systems to work on, or someone else would. I worked there for 4 years after that. And I still have the beard. :)

It isn't just the smell, Dan. This isn't the aqueous (mixed with water) ammonia that you get at the supermarket. Pure ammonia seeks water. It actively attacks moist areas of the body, going for the eyes, armpits, groin, etc.

Still, some people love the stuff. Must be a macho thing. To each his own. :)

26-06-2001, 09:49 PM
Gary, Nh3 work is different nowadays. If you have a minor leak the detection systems flag up a warning, slightly higher and the plant shuts down bringing on forced ventilation. Techs have it easy nowadays leaks are detected sooner before they are a major problem. Masks are still necessary but only occasionaly. Also with the advent of low charge Nh3 systems of the low pressure receiver variety charges are only a fraction of the older pumped systems. Ofcourse pumped systems have their place but less often nowadays.
Regards. Andy.

26-06-2001, 10:28 PM
This is all very good, Andy, and long past due.

Everyone in the company was hazmat trained and certified for the full moon suits (not to be confused with the sissy splash suits we always see on television). A lot of people have been killed by ammonia spills.

As an interesting aside, most of the ammonia techs I know are into scuba diving. Just a step short of the moon suits.

27-06-2001, 08:16 PM
Gary, no chance of getting me into one of those "moon suits" and as for the scba diving well I hate water and can't swim properly. Anyway the company I work for would have a dim view of me entering a plant room with a BA set, even though in the past I have completed BA training with the fire brigade. They say use a mask or escape set to get out and like a fire stay out. Even working in a NH3 plant room requires two people and breaking into a system requires authoriation from a superviser or manager. The latter may not always happen but it is the proceedure that I am supposed to follow.

Regards. Andy.

29-06-2001, 04:02 AM
I've probably spent 2000 hours in an engine room, I'm pretty sure 1800 hours I've been alone. I sort of think your way is better, but for most of the stuff I do, I'm hard put to imagine what a partner would be doing.

We're all fit-tested for BA, but there are only a few "hazmat technicians". We first made the older, more senior (AKA fat) engineers "hazmat technicians". Then they gave pre-drill/post-drill physicals and decided was not a good idea.

Came across something recently, fans like fire departments use for smoke ventilation are just dandy for taking the sting out of a leak while you wait for the line to clear.

Jim Heffernan
Tillamook, Oregon, USA

29-06-2001, 04:23 AM
For those who don't know the jargon:

BA = breathing apparatus
SCBA = self contained breathing apparatus
SCUBA = self contained underwater breathing apparatus

29-06-2001, 07:03 PM
Jim, nice to here from someone working on pump systems. Nowadays I work less on pumped plants but in the past that was all I worked on. I remember one large leak where the plant (a coldstore) was shut up for the weekend during the weekend a 1/4" hot gas pilot line fractured to the top of a powered suction valve, over the weekend 2500Lbs of NH3 was pumped out through this line. One arriving on Monday morning I tried to gain access, but the NH3 started to come through the mask, the only way I could find to suppress the NH3 even with the plant off was to get one of the coldstore staff into a mask and equipped with a cold wash power washer he hosed me and the air in frount of me until I reached the gantry where the valve station was to isolate the leak. No harm done except I was very cold and wet and the brand new coldstore truck which was once black and red was now red and green.
Regards. Andy.

30-06-2001, 01:47 AM
I've always heard of using water spray, but have never used it.

One good thing about working in a cheese factory, its a 24/7 operation and there's always someone around. I've heard a lot of sad stories from cold store guys.

A couple of years ago, I thought I was opening a valve on a liquid distribution manifold. Turns out the valve was already open and I was unthreading the bonnet. Later on, I was impressed the manufacurer machined a port in the valve so that NH3 sprayed to the side before you got to the last thread. I was able to immediately shut the main supply. After a while, I used a fan and cartridge resperator to get back to the valve and replace the bonnet. I hope "bonnet" is the right word for the top of a hand valve assembly.

I'm sure impressed by the new-to-me high effeciency fans that fire departments use for smoke ventilation, the also excel as confined-space ventilation.

Jim Heffernan
Tillamook, Oregon