\"It's all alchemy!\"

Rich L.

You got it Mike, NH3, one moecule nitrogen to 3 molecules hydrogen. All substances naturally occuring in our atmosphere!

Unknown

Best comment...

I heard from a lookie at the Hartford Homeshow. I was displaying the ammonia based heat pump as part of my equipment offerings. This guy comes into my booth and looks everything over, then he turns to me with a cross look on his face and says, "It's all alchemy!"
I laughed and said, "Yes sir, it absolutely is..." and he turned and walked away.

A fair portion of my time was spent either explaining how it puts out more energy than we put into it, which many people insisted was impossible because of a little thing called physics, or how it's nothing at all like the CFC based heat pumps that they've all heard bad things about.

BTW, for those who've been following this story. The Glastonbury CT house, 12,000 sq ft of heated area, uses gas for heat, hot water and cooking. They also have gas fireplaces everywhere but noone knows how often they use them. Conn Nat Gas (CNG) stopped by and told us that their PEAK bill this winter so far was $500.

Alchemy indeed...

Maine Doug_70

Now my wife

who is an Alchemy buff and teaches thermodynamics might have a different perspective but Alchemy is OK for me.


>>>how it puts out more energy than we put into it<<<

Rich L.

Gas fired Heat Pump

Who makes this MPF? Have you put any in? You've piqued my curiosity, I want to know more, a website perhaps?

Thanks, Rich L

Unknown

link...

http://www.robur.com/us/pag_news_dett.jsp?id_news=268&cat=13

one more... http://www.robur.com/us/pag_prodotto.jsp?idl=5&idp=87

[Deleted User]

thanks for the links

would you explain the ammonia connection?

Unknown

Sure,,,

It's old fashioned gas fired ammonia based (ammonia as the refrigerant)absorption cooling. Servel/Arkla used to be the mfg but Robur bought them out several years back, made major improvements to the original product and also developed the ability to reverse the cooling process so it can extract heat from either the air or a water source, "combine" it with the heat from the gas fired section and actually have btuh output exceed gas value input. By as much as 150% under certain conditions.

So when the physics people get all excited about getting more out than went in they are missing the point that the extra heat is coming from the air or water source, depending on the unit. "The News" is supposed to feature it and the Glastonbury house in a product focus article in the June 23rd issue that will contain most of the details on the project if you're interested.

[Deleted User]

ah,

the only ammonia-based units that i'm familiar with are some rather huge chillers at a local milk plant, and the first thing we were told about is the danger/evacuation aspect of ammonia

i'll def keep an eye out for the article

thanks

Unknown

Yup...

Everybody worries about the ammonia. The air source is an outdoor unit, if the ammonia leaks it just blows off outside. It is biodegradable. All the tubing is cold rolled steel and the components are stainless. I wouldn't say a leak is impossible but it sure is unlikely. Another advantage over colorless / odorless "Freon". Ammonia is not odorless. If there's a leak, you'll know right away and the correct procedure for the untrained is to get away from it.

Rich L.

Absorption Refrigeration

MPF, thanks for the links, very interesting. Have you been to their training classes? I'm still not real clear on how they tie in the gas with a ground loop or air?

Mike, the ammonia systems at the milk plant you're talking about still use the "basic refrigeration cycle" we're all familiar with using a compressor for the power source. These heat pumps use an absorption refrigeration cycle that actually use heat for the power source. That heat can be: gas, electric, oil, solar, etc. A perfect example is a refrigerator in a camper. It can run on LP gas or electric. Either method supplies heat as the power to run the cycle.

A gas refrigerator uses ammonia as the coolant, and it uses water, ammonia and hydrogen gas to create a continuous cycle for the ammonia. The refrigerator has five main parts:

1.Generator - generates ammonia gas

2.Separator - separates ammonia gas from water
3.Condenser - where hot ammonia gas is cooled and condensed to create liquid ammonia
4.Evaporator - where liquid ammonia evaporates to create cold temperatures inside the refrigerator
5.Absorber - absorbs the ammonia gas in water

The cycle works like this:
Heat is applied to the generator. The heat comes from something like gas, propane,electric, solar, etc. In the generator is a solution of ammonia and water. The heat raises the temperature of the solution to the boiling point of the ammonia.
The boiling solution flows to the separator. In the separator, the water separates from the ammonia gas.
The ammonia gas flows upward to the condenser. The condenser is composed of metal coils and fins that allow the ammonia gas to dissipate its heat and condense into a liquid.
The liquid ammonia makes its way to the evaporator, where it mixes with hydrogen gas and evaporates, producing cold temperatures inside the refrigerator.
The ammonia and hydrogen gases flow to the absorber. Here, the water that has collected in the separator is mixed with the ammonia and hydrogen gases.
The ammonia forms a solution with the water and releases the hydrogen gas, which flows back to the evaporator. The ammonia-and-water solution flows toward the generator to repeat the cycle.

Unknown

Yes,

I spent a few days at the headquarters in Evansville, Ind. and went through the whole thing there, although the classes were geared toward the standard chiller/heaters and not the heat pumps. They also concentrated on the DDC board which is a pretty good piece of technology itself.

I was in a class with people from Mexico, the Dominican Republic, Boys Town and some guy out in the northwest who currently buys the chillers half built, installs his own oil burner setup to finish them and burns waste oil to cool buildings.

They're going to have another session here at Clover corp, East Hartford, CT somewhere around April 15th. FYI

Thanks for the explanation on the ammonia cycle. It's a mystery to a lot of people but when it comes right down to it it's actually pretty simple. Not a whole lot of moving parts. In the Robur there is a diaphragm pump that circulates the water for the refrigeration side. So it, the gas valve, the inducer motor and the condenser fan motor are the only things that move on the chiller. Add the reversing valve if it's a reversible heat pump.

They reverse the evap and condenser accordingly just like a CFC heat pump. The reversing valve is much more involved and looks a bit like a centipede. It is actuated by a solenoid directly and not by gas pressure.

Plus, most, if not all, of the parts are "made in the USA" and shipped to Italy for assembly so most of it is generic off the shelf stuff. The only out of the ordinary thing in all of this is the reversing valve. I'm not sure where that comes from. It is a proprietary device.

[Deleted User]

ammonia leak

what about repairs if there was a leak? easy to repair? would a tech need to carry ammonia on his truck? etc

[Deleted User]

yes, thanks

for the exp. i sure wish i could make that class

Unknown

I just...

edited the last post a bit if you want to reread

Rich L.

Classes

I checked out the links and saw they have the training in Indiana going on right now. I'm in Eastern Iowa and that's a lot closer than East Hartford! I'll have to watch and see when they have it there again. Do you deal directly with them or do you have a local rep?

Unknown

Leaks...

Just to address this, I just saw the question. The refrigeration system is entirely welded steel tube coated with epoxy. Stainless steel components being the only place where mechanical type connections occur. Mostly bolted flanges. If the tube should somehow develop a leak or I needed to replace a component, I would have to hire a pipe welder. Theoretically, the systems are so leak resistant (we'll call it) that the stuff should stay in there for the projected 30 year lifetime of the appliance. I personally do not stock ammonia.

Another interesting aspect. Slow leaks. We all know the misery of that slow leak we just can not find. Well, in the water solution on the refrigeration side they put zinc chromate as a rust inhibitor. Zinc chromate is a bright yellow mineral like substance. See any bright yellow encrustation on your flanges or maybe at a weld somewhere? No? That's good. Yes? Guess what, there's your leak.

Unknown

yea but...

They only got good German food out there. We got good Italian food.

Unknown

Clover Corp...

is my local rep.

[Deleted User]

thanks for the explanation

the ammonia chillers i'm refering to are commercial, wind socked, alert the downwind residents, evacuation proceedures required systems

the 30yr lifetime, and the z-chro idea are comforting

Unknown

No problem..

I just called them. They say 16 lbs of ammonia and 30 lbs of water in the refrigeration side but will double check. He, Rick Halbig, said in his 25 years of working with ammonia there has never been a liability issue with leaks.

He went on to say they run 3 leak tests. 1. A rupture test to 2x operating pressure, 2. submersed in water while under pressure and finally 3. They introduce ammonia and nitrogen under pressure, wrap all the joints etc in litmus paper and wait to see if it turns purple which identifies even the tiniest of leaks. He said this has always been the process, even pre Robur. THEN they are sent to a capacity test room where they are charged and run for an hour to ensure correct capacity outputs and operating parameters. They are very meticulous. As far as leaks he said they have always been related to rough handling in shipping. There was also an instance where a batch got through with paint on the mating surface of some flanges and that casued a very slow leak problem but that was worked out years ago. I asked about reversing valve failures and he said he is not aware of any. I forgot to ask where they were made. Doh!

Brian_18

Funny, as Old technology is Reborn

My grandparents had a gas fired refrigerator (40yrs ago). It was an ammonia system. I wish I had it now, just for the novelty factor.

Unknown

From Rick...

Hello Mark,
My numbers were off. It appears the heatpumps have a different ratio of ammonia and water. For the GAHP-AR my guys are telling me the following:

Ammonia 17.1 lbs.

Water 22.1 lbs.

Regards,

Rick

[Deleted User]

very, very interesting

i'll turn the seniors at the shop on to it tomorrow and see what they say

and.......i just picked up my '68, 'modern' refer a/c book and it lists r-717 as ammonia, a compound of nitrogen and hydrogen

Unknown

Joke...

Ammonia = fertilizer so the joke is when it leaks you hose it down with water to dissolve the ammonia and for a few months afterwards the grass grows really good around the unit.