Posted by willbanks on September 21, 2006, 7:18 pm
I need a little help. I have for years thought about building a solar
thermal AC unit (ammonia-water system) but I lived farther north so the
trouble of building it to only use it a month or two wasn't worth it. Now
that I've moved to southern costal GA I think it would. Now that I'm
getting serious about it I can't find any 'hard' plans nor even much info.
The first unit I'd like to build would be in the 3 ton/36,000BTU range.
With a 5+ ton unit to be built for a larger home in the future. The
instructor from the local community college has offered to give me a hand
but all of his studies has been in conventional AC.
Can anyone give me some input or at least point me toward some good info?
Posted by Joe Fischer on September 21, 2006, 7:45 pm
You need to study the safety issues and dangers
carefully before undertaking this project.
There are two types, much the same, and both
use dangerous and/or toxic chemicals.
and the other is the Einstein;
I remember something about a lot of these being
removed from commercial buildings some time ago,
and there may be some used ones available, but with
the recent high price of copper, the ones not in use
may have been scrapped.
I think concentrating mirrors and trackers would
be needed to heat oil, it would seem that 400 F would
be hot enough to make a unit work.
If it were me, I would want to have all radiator/
heat exchanger coils in the house to each be a continuous
tube in one piece with no connections in the house.
I had a Servel gas refrigerator in the 1950s, but
I don't know which process it used.
There may be other thermal units that don't
use such doubly dangerous gases, it might pay to
In freon A/Cs the hard part is evacuating
the system to a deep enough vacuum to boil any
water off and remove it, but in these two processes,
water is used.
It might be better to try to buy one.
Posted by willbanks on September 21, 2006, 11:45 pm
Been there done that ammonia is bad but not that bad in the open where the
unit would be located. On the up side its REAL easy to tell if you have a
my guesses would be: 1) it was cheaper to replace them with new high
efficiency compressor units. 2) the legal libility, someone a mile away
gets a slight smell of NH3 and they claim damage and sue.
Humm. . .copper and ammonia don't really get along do they. All the info I
have seen calls for steel, perferably stainless.
No oil involved. NH3 and water is all. You can build a 'one way' unit to
make ice with common pluming parts and a parabolic trough mirror. I have
plans for a unit like that that will make either 10 lbs or 10 kg of ice per
I even have diagrams showing an old "Icy Ball" which was sold years ago
which was basically two balls on a pipe. You heated one to drive the
ammonia into the other then set it so that ball was inside a insolated box.
Was said to keep the box cool for 24 hrs on a charge.
I haven't made up my mind about getting the coldness into the house. I'm
leaning towards a heat exchanger to cool water and using a large radiator
and fan to do the house cooling. That would mean that any leaks would
either be outside or contained in the closed loop of the cooling system's
Most likely NH3.
I'm thinking the hardest part of this is going to be getting the anhydrous
ammonia. I'll only need small amount and that's just what the meth makers
That's no fun. May as well tell people to buy a solar oven 90% of the fun
is making it :)
Posted by Morris Dovey on September 22, 2006, 12:31 am
willbanks (in huFQg.firstname.lastname@example.org) said:
| I'm thinking the hardest part of this is going to be getting the
| anhydrous ammonia. I'll only need small amount and that's just
| what the meth makers use.
Hint: It's also what a lot of farmers use. If you're prepared to show
that you have a legitimate alternative-energy project, I'd guess that
you'd win a lot of cooperation from farmers, at a farm co-op, and
(perhaps) even at the USDA extension office in your county...
DeSoto, Iowa USA
Posted by willbanks on September 22, 2006, 3:58 am
Not a lot of farming down here. I haven't gotten to the point of trying to
find a supply much less seeing how many hoops I might have to jump through
to be able to buy it.