Rocket cooling/refrigeration

We're already working on a home heating system that circulates thermatic oil, heated by our big rocket stove, to heat exchangers/radiators in the home. We'll be adding a way to heat the oil via solar as well pretty soon.

I am wondering if that hot oil can also be the source of heat for an absorption refrigerator/freezer or even an absorption air conditioner. The oil hits 500 degrees F pretty easily. Would that be hot enough?

Also, what modifications would we need to make in order to use the oil as the source of heat, rather than a burner? Is a DIY project like this even possible?

If the hot oil will work as the heat source for an absorption chiller/refrigeratot/air conditioner, it would be fairly straight forward to add a solar heater to the mix. Probably, a solar trough would work best. A solar dish would also work, I think.

If the storage tank holding the bulk of the oil were insulated well, the oil should continue to work long after the stove is out or the sun goes down.

I didn't find any residential size absorption air conditioners during a quick google search, but I did find absorption freezers/chillers. We could circulate a cold water/alcohol fluid to a radiator in the home for A/C if absorption air conditioners are not on the market.

Any HVAC folks here who might give us some insight on this idea? I'm no expert, but it seems like we would need to stick whatever part of the chiller needs heating into a container of hot oil. Oil would be circulated out to the stove & back into the container again.

At 500 F, will the oil provide enough heat?

More than enough. If you look at refrigerators that work on an absorption cycle, like the Einstein refrigerator (an ammonia/water/butane system), the hot side of it just has to have a working temperature high enough to vaporize butane, which is a lot lower than 500 degrees. Your engineering problem is going to be how to control the heat transfer so that you provide enough energy to the high temperature reservoir to stay matched with the amount of heat you want to reject from the low temperature side.

You can look up the Einstein patent (circa 1930) and there was some work done by a grad student at Georgia Tech in the '90s, but the technology is really in limbo. The only place where absorption refrigerators have made any headway is in the RV market. And while work has been done to make refrigerators (for food storage), less has been done to adapt the technology to air conditioning type applications.

DIY is possible, I have been tinkering around with a solar powered Einstein cycle, but you need to be your own engineer, because there is precious little expertise available out there.

This is interesting considering that it was built in the 1920's:
http://en.wikipedia.org/wiki/Icy_Ball

Here is a more modern DIY one that you can buy plans for:
http://lionheart.net/fridge/descript.htm

The system above is similar to this solar one:
http://www.cedarcreeksoftware.com/solarice.pdf

They both need a heating and cooling cycle. The Solar system uses the natural day/night. The other one requires a person to open and close a valve.

This could be adapted very nicely into RMH.

Nick Kitchener : O. K., I'm shooting from the hip here, if someone got the plans for one of these Lionheart 'Icy Balls, and made it work, by using a kitchen stove,
or a camp stove (probably 'White Gas')! I would be very temped to build one for a back-up and some research down the road in bio-gas, i.e. methane ! The
price for the plans, and the price for a carefully built Unit is very doable - I will take the next step and send Stephen Peck an e-mail at -

'' stephen@ flowingriverchurch.com ''

I specifically want to ask him about the possibility of a video showing its safe operation ! Also I want to ask about a parts list which he may not want to 'give away'!

I can already note that it looks like the galvanized piping 'TEEs' that he is using are not boiler grade fittings! When you buy a section of ready made pipe it has been
cut to length, reamed to remove burrs on the inside of the pipe, and then threaded with a pipe die. This creates a set of tapered 'male' threads! these are supposed to
mate with fittings that have been cut to have tapered female threads, unfortunately, unless you specifically request Boiler grade fittings you are very likely to get fitt
-ings where the threads were cut on a boring machine that made and threaded the female fitting without a taper - it's faster and cheaper ! You have to order boiler
grade fittings to be sure you are getting a tapered 'female' fitting, or train your eye to tell the difference, and check every time! Most 'regular' boiler fittings are made
from Black Iron Pipe, not galvanized, and not stainless steel, I wonder (because I do not know !) if you should not try to make up this 'Icy Ball' with Black Iron Pipe
fittings, for the same reason that you should not use Brass fittings - corrosion !

I will give you a report on how I make out !

For the Future/Good of the Craft ! Be safe, Keep Warm ! - As always, your questions and comments are solicited and are welcome ! PYRO-LOGICALLY Big AL !

It'll be an interesting adventure indeed!

I looked online and there are a few comments on the plans. The comments I found said they were disappointed to find that you needed someone operating it the whole time so that they can open / close the valve to complete the cycle.

I guess they were expecting a modern automatic system.

It would be worth asking before you buy the plans if the author thinks they would be suitable for the application you're thinking of.

This sounds beyond my skills at present. Thank you all for explaining it. At least I know the oil has more than enough heat. Maybe something will come of that down the line.

My thinking was to use oil to both heat TEG's and to run an absorption freezer, full of antifreeze, which would be pumped to the cold side of the TEG's. LOL.

Wasn't trying to get something from nothing. Just trying to get more from one source.

Alas, that doesn't look doable at present. Won't stop me from trying to figure out AC and refrigeration, though, so I'm sure I'll come up with some other crazy scheme down the line.

During the winter months, the oil & TEGs should work well, since the cold side can be provided using the freezing outside temperatures. But, in the summer this setup doesn't make sense to run if a freezer is used to cool the coolant. Seems like the TEGs would spend all the energy running the freezer.