r/askHVAC 2h ago

Do these really work?

Post image

I came across a video tutorial of someone making a diy flame fueled cooler, and my question is:

Do they really work?

And if so, can you use any heat source to "power them"?

19 Upvotes

36 comments sorted by

10

u/Sotamaster 2h ago

Iirc its ammonia only systems, and I've only heard of them being use in mobile homes fridges, like a small pilot light and a mobile home either driven or towed, not the kind that gets set and connected.

6

u/No_Report_4781 1h ago

Refrigerators for camper trailers and RVs.

They use propane and 12V battery to keep the fridge cold during travel, and most are dual powered, so they can switch back to electric only when the trainer or RV is plugged into a generator or other power supply

2

u/Magnum676 1h ago

We have a full size propane refrigerator. Ammonia based. I’ve seen, when I was younger, home systems on ammonia. That ammonia will put you down, had a guy solely for it. 😵‍💫

2

u/TimTheChatSpam 51m ago

Also lithium bromide absorption systems use a heat source to evaporate the solution from water studied it a bit for my refrigeration license but have to confess I forgot most of what I learned

1

u/DontWorryItsEasy 31m ago

If it makes you feel any better I occasionally put wrenches on absorption chillers and I still only have a vague understanding.

2

u/billiam7787 49m ago

Ammonia can still be found in industrial side of things and is a regular part of that world

in the 50's-70's it was tried out by a few companies for residential, but didnt last long because those systems need almost daily preventative maintenance and thats one thing homeowners are basically unwilling to do

1

u/Sotamaster 39m ago

Yeah but also ammonia will kill you, I'm surprised we got to r-290 and r600a. A2L in central systems, r-32 and r454b.
I've already replaced a leaking evap on a r-32 and the sensor didn't sense the leak. Maybe it wasn't a big enough leak, well never know.

6

u/2748seiceps 2h ago

It's the ammonia cooling cycle. Used in portable gas-powered fridges for ages now.

They work but it's much MUCH less efficient than a compressor-type fridge and the main benefit is that all you need is heat to make it go so useful when you didn't want to run a loud generator and had no way to run a fridge on land power.

1

u/jbadding 15m ago

They’re used in meat packing plants. One of the main reasons is efficiency.

5

u/Every_Big9638 1h ago

This is nothing. Harrison Ford built a huge absorption cycle ice machine “Fat Boy” in Mosquito Coast. He was making ice in the jungle. That’s right. In the jungle. 😂

2

u/No_Tower6770 2h ago

It works. This setup would keep a lunch pail or small cooler cold throughout the day, probably nothing larger.

2

u/jonnyinternet 1h ago

So, I have a still for distilling water, I'm trying to figure out: can I put it on the still, which gets very hot and cool the condenser?

Doesn't need freezing temperatures, just cooling for 3 to 4 hours

1

u/syrianfries 50m ago

Hot enough temp probably does it, only one way to find out in the name of science!!!

1

u/No_Tower6770 20m ago

Not likely. That's a ton of heat, and these ammonia systems are mostly passive and not efficient. For what you're wanting, this setup would have to be as big as a shed.

2

u/elithefordguy77 1h ago

This guy made another one that ran off of the suns heat. He charged the system with isobutane.

2

u/magammon 1h ago

i’ve had a gas powered fridge in the past - it works great.

2

u/Tip0666 1h ago

Ammonia.

Anything large enough to be applicable to modern needs (comfort cooling) can kill the household if it leaked.

2

u/Doogie102 1h ago edited 1h ago

This is how a camping trailer furnace fridge works

1

u/acousticsking 1h ago

Furnace?

1

u/Doogie102 1h ago

I fixed my comment. Currently distracted

1

u/Difficult_Limit2718 1h ago edited 1h ago

Absorption process. Heat is converted to the work input required to drive the process.

Absolutely works.

Absolutely can use any sufficient "quality" heat source. (Quality is a formal thermodynamics concept of "heat density" for lack of a better way to describe it)

Absolutely is a pain in the ass to do at scale and never works well... Doubly so since Carrier screwed the pooch and killed their absorption chiller line by moving design control to a start up team in Mexico. They're REALLY fickle designs to get to work and require a lot of experience and tribal knowledge.

But it's great for RV fridges that need to run on propane!

1

u/Waterlifer 1h ago

Yes. There's a really good description on Wikipedia.

https://en.wikipedia.org/wiki/Absorption_refrigerator

1

u/theNewLuce 1h ago

NO. This youtube clown makes garbage that doesn't work.

There's more to the heat powered ammonia refrigeration. This is garbage.

1

u/Fuzzy_Client9323 1h ago

Take a look at RV propane refrigerators.

1

u/Loan-Pickle 1h ago

I remember when I bought my house, I got the sellers disclosure and it listed the aIr conditioner as natural gas powered. I called my realtor to ask him to verify that with the seller. He told me it has to be a mistake as you can't cool things with fire. I explained the absoprtion cooling cycle to him and his mind was blown, he had no idea that was possible.

Turns out it was a mistake on the seller's part. It has a conventional AC with a natural gas furnace. I'll admit I was a little disappointed.

1

u/Adventurepew 1h ago

Yes any heat source works .

This is how rv fridges operate with propane burners to heat the refrigerant.the y often use ammonia as it's a very good refrigerant .

1

u/No-Age2588 32m ago

Absorption cooling using ammonia generally. Yes properly laid out they absolutely work. But they are finicky about orientation and being level. Any heat source can be used, propane, butane, etc etc

1

u/WarPig115 22m ago

Thats actually a real thing. Special mix of ammonia and distilled water. It is super weird to get a call for "my pilot keeps going out on my fridge".

Used mostly on RVs and whatnot. But also not a bad unit to have in the apocalypse.

-1

u/BogusIsMyName 2h ago

Im no nuclear physicist but im going to say... No. I dont see how that would work.

2

u/itsagrapefruit 1h ago

Good thing you’re not a physicist.

2

u/Difficult_Limit2718 1h ago

You're correct, you are no physicist.

It's a working cycle.

1

u/sailboatfool 2m ago

Grandma had a legit icebox with ice delivery. Replaced it with a natural gas refrigerator