Backyard Aquaponics
A place to discuss aquaponics

I heard recently about a thermal chiller that is available, also heats.
I found this, but can't get much technical know how from the clip http://au.youtube.com/watch?v=AtMC2MXc_n8
Anybody heard of this? Is it any good? The guy telling me is a new technology design consultant, working mostly in waste disposal using biodigesters.
Perhaps this (if even vaguely affordable) will satisfy those wishing to keep Trout over summer?

I forgot, Andreas said they were building systems with the equivalent cooling of a 10kW standard electric refrigerative system...

They say a lot about how good it is but nothing about how it works. I presume it cools as the water changes to a gas and then back or are they using the hot water to heat the refrigerant. But 10ton to cool a small building seems a little on the large side. And heating water will leave a residue to be cleaned out. Replaced an element in my cappuccino machine and the water chamber was over half full of calcium.

I was rather bemused by the Egyptian example at the end .

The idea is an old one, not revolutionary, just forgotton like a lot of good ideas. They take up a lot of room, which is why they are rarely used today, but they can use direct heat. I had one on my Nuke Sub back in the 1980's.

Absorption A/C works by using the priciple that some chemical like to absorb water vapor. If you pull a vacuum on water it can boil all the way down to freezing. If you put lithium bromide in water and put it in a closed volume with nothing but water vapor- no air, it will make a vacuum by absorbing the water vapor.

If you have some interconnecting tanks you can make AC like this. One tank has cold concentrated bromide that is being cooler by circulating water through cooling coils. Another tank has dilute bromide that is being boiled and concentrated. A third tank has pure water in it with coils that provide cooled water to provide AC. The concentrated bromide is kept separate from the pure water, but shares the vapor space. This causes the water to boil in a vacuum at around 40 degrees F. As the bromide absorbs the water vapor it gets warm and diluted. Some is pumped off to be boiled and concentrated, then returned. The water vapor formed is condensed and returned to the cleam water side. Put in heat and get cold out.

I used to have a fridge that worked on a similar priciple, but used ammonia, hygrogen and water. There were no moving parts and it was powered by a pilot flame. You can still buy those, but you have to look pretty hard for them.

Aha some1 on here does know something about it! Thanks for your info badflash. Tell me, is this how a gas powered refrigerator such as you'd find on a boat work? They have a small flame burning constantly too.

Sounds interesting. But at the end of the day I think using cooling tubes under ground might be a easier system. Just a pity that towns are not planed and built using some of these ideas.

Yes, the refers on boats and RV's are often ammonia.

The big downside of most of these systems is the up-front cost. Absorption systems cost about 10X as much as the conventional system and have a huge footprint.

"Tell me, is this how a gas powered refrigerator such as you'd find on a boat work?"
Yes and all the 3 ways in caravans. Usually use ammonia, find one thats not cooling properly turn it upside down for a while and off she goes again.

KP, does the solar ice thread help you at all?
viewtopic.php?f=31&t=1934

Ahh... already a post about this
Thanks Steem.

Researching...

I had a home made ice maker. It was made from a 10 gallon propane bottle and a small mini oxygen bottle. The large can has water in it. The small bottle had ammonia in it. There were two lines between the two. One with e needle valve and one ball valve.

To make ice you just placed a bag over the small bottle and inserted in into a 5 gallon bucket and cracked the needle valve. The ammonia would evaporate freezing the water and being absorbed into the water. Then to reset the device you closed the needle valve and opened the ball valve, placed the small bottle in a bucket of water and set propane bottle into the hot coals of a fire. When the large bottle reached 212 F(the boiling point of water) you were finished removing the ammonia from the water; close the ball valve and it was read to use again once it cooled down.

I know there are commercial systems that use solar heat do do similar things.

Most Campers and RVs have those Ammonia type refridgerators and they are quite effecient. The problem with those as my brother found out one day at our deer lease is that when it leaks out it fills the living area of the camper with a deadly gas. On short term exposure it burns your eyes, skin and make you extremely nausous. I believe it is a controled substance and takes special licences to work with the stuff.

You may want to see this before experimenting with that stuff
It is really wicked stuff.
http://msds.chem.ox.ac.uk/AM/ammonia_anhydrous.html

I guess that the safety of lithium Bromide over ammonia is why is used on confined spaces like the Sub.