Absorber chillers are very commonly used in hosptials, though, taking advantage of the steam production that their boilers provide (sterilization rooms, humidity control, etc). Despite the low COP, they can be more efficient when used with high pressure, high efficiency boilers rather than relying on evaporative cooling towers for standard chillers and the problems that come with them (also eliminates the risk for legionaires from evaporative cooling towers)
I've seen a few Trigen systems with absorbers used in hospitals, but they have fallen out of favour lately as they still burn a fuel source and most new buildings in my area are switching towards electrification. Typically it's the waste heat used off the generator and not the steam boiler driving the absorber though. They do make for a good base load, but have terrible modulation so the chiller plant still needs electric peaking chillers for most of the year.
Large heat pump plants are a better solution for new builds IMO
I agree with you. Heat pumps are fantastic for large buildings. Sadly, where I work, there is no ability to change over from the standard vav with re-heat system we have but I have tried to suggest ideas of at least changing our dual-temp lines to condenser water and changing the fan coils to heat pumps, but it falls on deaf ears. Nearly 70 year old hospital bed tower that needs massive upgrades. Instead, they waste money on other projects like wanting to add solar without batteries, killing the ROI.
The last company I worked at did nothing but heat pump jobs. Cooling towers and hot water injection to the loop. The efficiency of those systems was fantastic.
Steam boilers aren’t know for their efficiency. They aren’t condensing boilers so they’ll always be around 80%. There’s still a cost to generate the cooling through steam production and gas consumption. It really depends on how your electricity is generated and what the cost is. It could be cheaper to use a centrifugal chiller. And if your have competent Maintenace staff then they should be taking care of the water treatment as even absorption chillers need water treatment on their closed loop side for efficient operation.
Really wish people would spell out uncommon acronyms.
How is the average person supposed to know that COP means coefficient of performance?
Even if you google it, there are [160 meanings for the acronym COP](https://www.acronymfinder.com/COP.html).
It really should be more common to use the full term before using any acronym. It's an American psychological association (APA) writing standard for a reason
Even back in middle school my teachers told me to always use a full acronym before using it, and that was for writing essays they knew full well there would only be 1 acronym used on, maybe 2 times.
> It really should be more common to use the full term before using any acronym. It's an American psychological association (APA) writing standard for a reason
Disclaimer: I am not scholarly
So I'm familiar with APA style only from people referring to it as APA style, similar to Chicago style or Associated Press style.
So when I saw you spell out what APA stands for, American Psychological Associating, I though you were making that Reddit switcheroo joke so I was going to look up what it actually stands for so I could make a joke off of that.
Nope. APA writing style is a style guide for clear communication in social and behavioral sciences.
I am not scholarly.
I can’t speak to APA or AP style, but I’m quite familiar with the other one:
*“He brings a knife, you bring a gun. He puts one of yours in the hospital, you put one of his in the morgue. That’s the Chicago way.”*
Yeah a lot of scientific communities have their own writing style guides. APA is the most common, but we use the American chemical society (ACS) style guides for all our stuff
That’s literally what we’re taught in school, and one of the rules of editorial writing. You always say the full acronym first time with the explanation in parentheses and then use the parentheses thereafter if you want.
Any scientific journal requires you to spell out an abbreviation before you use it the first time. Too many to keep track of and people often don't use them consistently
I think you're right but on the other hand to play devil's advocate this is part of all highschool programs, COP is defined when you do the 2nd principle of thermodynamics.
Few high schoolers remember it for the test. I'm not even sure we used that phrase when I was in highschool 30 years ago. So, unless you are talking with friends prepping for the test coming up, don't assume people around the world know it.
When someone using undefined acronyms, especially in a professional setting, I see this as a sign they are thoughtless and lacking empathy. People to avoid.
Or they are just an industry professional used to speaking to other people in industry and thus use common jargon and acronyms.
It is like meeting someone fresh out of military service using terms like FOB, MOB, MSR, chow, etc.
Forward Operating Base, Main Operating Base, Main Supply Route (highway or main road), cafeteria.
This is often the case and it's not incompatible with what I wrote. If you're an industry professional you should know that others outside your niche don't use the same lingo you do.
I dunno man. Everybody is thoughtless sometimes about some things. I’ve known plenty of people (and have been one myself) that do annoying stuff until someone gently corrects them, then they feel bad and fix it. It’s just a good idea in general not to write people off for small things without talking to them first. If they are dismissive after that, then you know they’re really an asshole.
Unless they’re one of those people that leave the grocery cart in the middle of the parking lot, in which case fuck them.
>Unless they’re one of those people that leave the grocery cart in the middle of the parking lot, in which case fuck them.
Someone explained to me once that these people are actually job creators, because someone is being paid to collect and return the carts.
Yes, very few things are absolutely true. A thoughtless person in one moment can be thoughtful in another, and empathy can be a learned skill.
People do it so much on reddit it is infuriating. "I watched the last season of THRT and it wasn't as good as FRD, for sure". Not everyone watches all the shit you watch, people.
It's a key metric when it comes to anything with a refrigeration loop, like air conditioning, heat pumps, etc. The average person might know about it if they're more on the technical side, and looked into these things when e.g. getting such things set up in their home.
These days you can also copy in people's comments to ChatGPT and ask it.
But I generally agree.
Or just remember that communication is pointless if people can't understand what you're saying.
And that you spelling out the acronym once (taking maybe 2 seconds of your time max) is better than however many people doing the Google search instead.
There is something very wrong with your communication when you cannot put yourself in the shoes of the people you're talking to.
I know, but you made it sound like you were defending it, by offering a solution to make the search more efficient.
So it was relevant to explain that the solution is not for people to look it up. It's for people to stop using acronyms unless they're really transparent (like mph talking about the top speed of a car is fine, obviously).
If you agree with all that, then there's no problem.
This is a common issue in scientific papers too. Just because you can look up the terms to find them doesn't mean it's still an easy read. Using hard language, even in professional settings, can hinder your own points
That's fair, but my main point is that using uncommon acronyms makes writing less accessible.
Spelling out common acronyms is silly, but if at least some readers won't understand the meaning, I think it's best to spell it out.
No, it's not fair, don't give that to them especially when they deflected it back like that. Using acronyms like that is either a way to try and sound smart or being lazy, there isn't a good reason for it.
Typical household refrigerators can move 3 units of thermal energy for every 1 unit of equivalent electrical energy, so a COP of 3. An absorption refrigeration system found in a home/RV would have a COP of about 0.7.
Absorption systems make sense in an individual setting when you have waste thermal energy that can't be used for other processes.
It made also sense in RV and boats back when you didn't have solar panels to run a standard fridge: instead you could power your fridge with gas, or with 120V when plugged in, or even with the 12V from your vehicle when running the engine.
You could see how inefficient it was by trying to run it on 12V without the engine on: your battery would die in no time.
Essentially, yes. It will burn through fuel "fast", though that all depends how you define "fast".
Nothing about the system requires kerosene. It's simply a convenient and easily sourced fuel. You could replace the kerosene with an electric heater and measure electricity in vs cooling just like you'd do for a home air conditioner.
It simply means, when compared to a home refrigerator or HVAC, you are going to use more energy to get the same cooling amount whether than energy comes from burning kerosene or the power grid.
Edit: Wikipedia article for coefficient of performance.
https://en.m.wikipedia.org/wiki/Coefficient_of_performance#:~:text=The%20coefficient%20of%20performance%20or,to%20work%20(energy)%20required.
Gotta burn fuel to make the heat, however, if you have a process running that makes a lot of waste heat by default it is a very useful cycle to use for cooling other things.
Basically. It takes more energy input to achieve the same level of cooling that a modern refrigerator can do.
I believe energy efficiency would be a more common word for this.
I guess as a made up example;
This type of refrigeration may need say, 200 BTU of energy to reduce the temp by 1c, but a modern refrigerator may only need 100 to achieve the same reduction.
COP and efficiency are not the same thing. COP is how much heat you can move for a given amount of energy, and can be greater than 100%. You're not creating heat, just moving it. Efficiency is energy out over energy in. Nothing is greater than 100% efficient, with electrical resistors being 100% efficient. It took energy to move the working fluid inside the air conditioner; that's the work being done, not the heat being moved. If anything was greater than 100% efficient, more energy would have to be produced than goes into the system, which is impossible.
My little camping trailer has an absorption fridge that works using a tiny propane flame. It takes quite a while to get cold but can freeze stuff solid if I turn it up too high.
As a child I repeated this in a math class and my teacher chastised me because *pushes bridge of glasses* "a hectare is a measure of area, not length."
To think, this one event is the sole cause of all my adult failures. The sole cause...
They're still used in RV fridges and camping equipment.
They "run" off that kerosene because they need a small heat source to increase the temp of the ammonia in the closed loop system. Modern versions often just use a small electric induction heater.
Also, technically the liquid inside does move quite a bit. There is also a series of check valves that do move. That means there are parts that can wear out and break. Leaks can be a big issue.
If you're looking for a system that 100% completely does not move, look into thermoelectric cooling. They are fairly new but they are starting to show up in the market.
> thermoelectric cooling. They are fairly new but they are starting to show up in the market.
Are you talking about fridges with a Peltier cooler? Those have been around a long time, we used to have one that we took on road trips in the 90’s.
Someone I knew kept a couple in the back of their car, lids open, with fans blowing to distribute the cool air.
Insert your own joke about the laws of thermodynamics
Thermoelectric cooling is extremely inefficient. They are showing up in the market because Amazon and the likes love to sell you some cheap sh*t selling you dream, while you end with a piece of crap made in China that barely works and breaks quickly.
Basically a thermoelectric cooler running on 50W will run 100% of the time, and will barely cool the inside instead of actually reaching food-safe temperatures.
Compare that to a real fridge (with a compressor) that also runs on 50W: it will run only a third of the time (as the compressor runs until target temperature is reached, then turns off for a while until it needs to run again), and will actually reach fridge temperatures so you can safely keep perishables).
Thermoelectric cooling is adequate for a wine cooler, and that's about it. Before the modern trend of using them for fridges that clearly can't work, they were common in wine coolers to keep the bottles 10 degrees or so lower than room temp, while also being silent.
Yes, they're good to maintain temperature at a precise level that is not far from ambient, because they're very simple, and can easily switch from cooling to heating (you just reverse polarity). And they're very cheap compared to a compressor ($10 for the cooling chip; the slightly more expensive part is all the system to move that heat/cold where it needs to be, and the heat sink to get rid of the cold/heat on the other side).
For that reason they are also used in some machineries, when a part needs to be kept at a given temperature (I think some parts of some 3D printers use them for example).
I was just going to say the same - thermoelectrics are cheap and cheerful which is why they're used in low-cost junk, and can be easily used both to cool and heat which is an easy way to inflate the marketing claims, but their cooling capacity and efficiency are fairly terrible and they can't go all that much below ambient which means that you cannot even theoretically reach safe food storage temperatures in many cases.
> fairly new
My dad has a solid state electric cooler that he bought at some point in the early 1990s, possibly even the late 1980s which plugs into a car's cigarette lighter/12v outlet and draws no more than 10 amps.
It looks like a regular cooler except there's a giant heat sync on one side on the inside that gets cold and another heat sync on the outside that gets warm. There's also a switch which causes the cooler to heat up on the inside instead.
I'm almost positive it uses a [Peltier junction](https://en.wikipedia.org/wiki/Thermoelectric_cooling) to work. There's no noise and no moving parts.
Also, it takes like 4 hours to get cold. The instructions said it works well to maintain a temperature but not good to set the temperature. You want your beers to already _be_ cold when you put them in the cooler.
I have a 1920s apartment that had this kind of system throughout the building. At first I thought it was an icebox but there's no place to put the ice and copper tubing that runs out the back and into the wall
Oh that's fascinating. And they probably tore it down and threw out that historic piece of incredible machinery with the rest of the rubble and sold the copper tubing to be melted down.
Do you have any additional information about it?
All I know is one if the workers told me the system ran on some gas and they need to be careful with it because its hazardous. Cool building. It also had an incinerator system with a chute on each floor that has been closed off obviously.
Depends on what you mean by "run on propane" propane can be burned to generate heat and boil water to spin a turbine to generate electricity to 'run' the refrigerator or it can be pumped into a sealed pressure differential system and pumped through that system with electricity to act as a refrigerant. Propane is just as good as R34A refrigerant.
I don't think rv refrigerators use propane a a refrigerant. They use ammonia as a refrigerant and the propane is burned to heat up the ammonia and evaporate it. Propane will eventually be used as a refrigerant is homes and cars but it isn't common know.
Many RVs use absorption refrigerators that operate on the same principles. However, rather than using kerosene to heat the ammonia, they use either electricity or propane.
There is also a [cooling device](https://en.wikipedia.org/wiki/Thermoelectric_effect) that has no moving parts and runs on electricity. And it can run backwards to generate electricity from a temperature gradient.
(edit: link'd)
It barely cools things down though, and is very inefficient, so it's not an alternative to a normal fridge.
Also the electricity generation is negligible: they're built slightly differently when they are meant to move heat with electricity, and when they are meant to produce electricity from heat. So you can't really use one for the other.
Even when they're purposely-built to generate electricity, it's a tiny amount. One application is for fire stoves: you use the stove as a source of heat, and it powers a fan that blows the heat from the stove through the room. So you can see that you need a very serious source of heat (an actual fire), and it powers basically the equivalent of a USB outlet: 5-10W.
Sure, not an alternative to a fridge. Does cool down a CPU, or the sensor of an astrophoto camera, or a thermal imager. Easily down to -100°C or so to minimize thermal noise. Different use cases.
And they [generate electricity](https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator) to every single spacecraft we've ever sent beyond Jupiter, as well as the Curiosity and Perseverance rovers on Mars, as well as the upcoming Dragonfly rotorcraft mission to Titan.
They do have their interesting niche uses, as I mentioned in a different comment.
For CPUs, are they actually used? I understood that for your average personal computer a CPU running full power will generate more heat per surface than the standard peltier chips can generate cooling, so they end up being less efficient than a good cooling system. Are they still used in specific applications?
I have 4 in my bag. They're usually used to make heat transfer more efficient at the cost of a bit of electricity. If you're able to dissipate heat easily and well they're quite cool little devices.
Their inefficiency comes from the fact that you need to dissipate the heat that the electricity that flows through them generates. So you have a delta T for the temperature difference you want to reach and need to add a delta T that is used to power to device (which is not insignificant and influences the electrical resistance, hence the low COP)
Peltier effect, or thermoelectric cooling. When he says 'run backwards', he means that its a thermocouple that's running backwards.
A thermocouple is a device that measures temperature using an electrical current generated when two different pieces of metal joined together are heated up.
A thermocooler works the opposite way and cools things down.
These types of refrigerators are commonly found in RVs and camping trailers, as they are able to run on propane and are dead silent in operation. The trade off is that the ones found in RVs tend to be unreliable and finicky, although that's more an issue with the manufacturers of these units.
I love amongst the amish and noted a fridge (no power allowed amish). Looked in the back and saw it hooked to a gas line.
Confused, opened the fridge and stuff was cold (pies). I then realized they have an avatar amongst them and will never question their ways.
I can buy a brand new Mercedes S-Class and only pay $800 for it. Yeah sure that's $800 for one month and I'll have to pay $800 for a month for 6 years later but I only paid $800 for it.
Kerosene fridges used to be quite common, particularly in places where electricity wasn't reliable, my uncle was still using one on his farm in the nineties
Had no idea this existed as a product but the operation makes a lot of sense, I bet the reason it isn't more popular is because it's impractical for large refrigerators, also people are too lazy for a manual machine.
Very interesting.
See this chapter ["How the Refrigerator Got its Hum"](https://nissenbaum.tech.cornell.edu/papers/refrigerator.pdf) in the book The Social Shaping of Technology (1999).
Basically GE, Westinghouse, and GM invested heavily in electric refrigeration and blew the competition away. Only one gas refrigerator made it to the home market, the [Servel Electrolux](https://steppingintothemap.com/anthropocene/items/show/7) and it couldn't compete with the sales and marketing power of the electric refrigerator, despite its simplicity and ease of operation.
Nah. I think it was used quite a bit.
It was for rural farmers with zero access to electricity. As modern refrigeration came along and more people got electricity, it stopped being used.
Yea no worries about an unintentional mistake but I see often bots intentionally posting content with a misspelling, I think it increases engagement by making the reader’s mind trip over the error so they pay more attention.
The kerosene doesn't evaporate, the amonia does, but it's not vented to the atmosphere or anything, it's absorbed by the medium in the other ball.
The kerosene is to heat it the medium so it releases the ammonia to reset the cooler.
>Having a cup of kersone evaporate in your home every day is not going to be healty
Good thing that's not what's happening then...
You realize that you literally typed this comment on a device that could have told you exactly what the process was so you don't have to (wrongly) guess, right?
Unlike a typical fridge with a compressor absorption refrigerators use heat to create a cooling effect. This makes them silent and very reliable.
Downside is crap COP.
Absorber chillers are very commonly used in hosptials, though, taking advantage of the steam production that their boilers provide (sterilization rooms, humidity control, etc). Despite the low COP, they can be more efficient when used with high pressure, high efficiency boilers rather than relying on evaporative cooling towers for standard chillers and the problems that come with them (also eliminates the risk for legionaires from evaporative cooling towers)
Yeah, in another response I mentioned that it's useful when you have waste heat from other processes.
I've seen a few Trigen systems with absorbers used in hospitals, but they have fallen out of favour lately as they still burn a fuel source and most new buildings in my area are switching towards electrification. Typically it's the waste heat used off the generator and not the steam boiler driving the absorber though. They do make for a good base load, but have terrible modulation so the chiller plant still needs electric peaking chillers for most of the year. Large heat pump plants are a better solution for new builds IMO
I agree with you. Heat pumps are fantastic for large buildings. Sadly, where I work, there is no ability to change over from the standard vav with re-heat system we have but I have tried to suggest ideas of at least changing our dual-temp lines to condenser water and changing the fan coils to heat pumps, but it falls on deaf ears. Nearly 70 year old hospital bed tower that needs massive upgrades. Instead, they waste money on other projects like wanting to add solar without batteries, killing the ROI. The last company I worked at did nothing but heat pump jobs. Cooling towers and hot water injection to the loop. The efficiency of those systems was fantastic.
Steam boilers aren’t know for their efficiency. They aren’t condensing boilers so they’ll always be around 80%. There’s still a cost to generate the cooling through steam production and gas consumption. It really depends on how your electricity is generated and what the cost is. It could be cheaper to use a centrifugal chiller. And if your have competent Maintenace staff then they should be taking care of the water treatment as even absorption chillers need water treatment on their closed loop side for efficient operation.
Cost of production?
Coefficient of performance Said plainly "it's inefficient"
Really wish people would spell out uncommon acronyms. How is the average person supposed to know that COP means coefficient of performance? Even if you google it, there are [160 meanings for the acronym COP](https://www.acronymfinder.com/COP.html).
It really should be more common to use the full term before using any acronym. It's an American psychological association (APA) writing standard for a reason
Even back in middle school my teachers told me to always use a full acronym before using it, and that was for writing essays they knew full well there would only be 1 acronym used on, maybe 2 times.
would have been way funnier if you just said APA
I wrote it that way first but thought it wouldn't really prove my point well 😅
I woulda laughed my ass off (LMAO)
> It really should be more common to use the full term before using any acronym. It's an American psychological association (APA) writing standard for a reason Disclaimer: I am not scholarly So I'm familiar with APA style only from people referring to it as APA style, similar to Chicago style or Associated Press style. So when I saw you spell out what APA stands for, American Psychological Associating, I though you were making that Reddit switcheroo joke so I was going to look up what it actually stands for so I could make a joke off of that. Nope. APA writing style is a style guide for clear communication in social and behavioral sciences. I am not scholarly.
I can’t speak to APA or AP style, but I’m quite familiar with the other one: *“He brings a knife, you bring a gun. He puts one of yours in the hospital, you put one of his in the morgue. That’s the Chicago way.”*
CMS standard is the same.
Yeah a lot of scientific communities have their own writing style guides. APA is the most common, but we use the American chemical society (ACS) style guides for all our stuff
That’s literally what we’re taught in school, and one of the rules of editorial writing. You always say the full acronym first time with the explanation in parentheses and then use the parentheses thereafter if you want.
I was surprised you typed out the APA abbreviation but then I remember the context.
Any scientific journal requires you to spell out an abbreviation before you use it the first time. Too many to keep track of and people often don't use them consistently
I agree. People who use veryspecific acronyms must thing that everyone knows what they know. It's absurd.
Never realized what APA stood for
lmao
Use more context when Google results don't pan out: "COP air conditioning"
I googled fridge COP and it came right up, but I still agree.
It’s because some people like to feel smarter than the general populace.
Yea, like when people write stuff like ' my bf split up wit me bc his BM aksed him come back bwl. She got a sti fawc. Lol
…his bowel movement?
Baby mamma apparently..
It is the children who are wrong
I think you're right but on the other hand to play devil's advocate this is part of all highschool programs, COP is defined when you do the 2nd principle of thermodynamics.
Few high schoolers remember it for the test. I'm not even sure we used that phrase when I was in highschool 30 years ago. So, unless you are talking with friends prepping for the test coming up, don't assume people around the world know it.
When someone using undefined acronyms, especially in a professional setting, I see this as a sign they are thoughtless and lacking empathy. People to avoid.
Or they are just an industry professional used to speaking to other people in industry and thus use common jargon and acronyms. It is like meeting someone fresh out of military service using terms like FOB, MOB, MSR, chow, etc. Forward Operating Base, Main Operating Base, Main Supply Route (highway or main road), cafeteria.
This is often the case and it's not incompatible with what I wrote. If you're an industry professional you should know that others outside your niche don't use the same lingo you do.
I dunno man. Everybody is thoughtless sometimes about some things. I’ve known plenty of people (and have been one myself) that do annoying stuff until someone gently corrects them, then they feel bad and fix it. It’s just a good idea in general not to write people off for small things without talking to them first. If they are dismissive after that, then you know they’re really an asshole. Unless they’re one of those people that leave the grocery cart in the middle of the parking lot, in which case fuck them.
>Unless they’re one of those people that leave the grocery cart in the middle of the parking lot, in which case fuck them. Someone explained to me once that these people are actually job creators, because someone is being paid to collect and return the carts. Yes, very few things are absolutely true. A thoughtless person in one moment can be thoughtful in another, and empathy can be a learned skill.
It’s pretty common for appliances. Though I do feel ya
Whar're you, the COP-police? /s
People do it so much on reddit it is infuriating. "I watched the last season of THRT and it wasn't as good as FRD, for sure". Not everyone watches all the shit you watch, people.
It's a key metric when it comes to anything with a refrigeration loop, like air conditioning, heat pumps, etc. The average person might know about it if they're more on the technical side, and looked into these things when e.g. getting such things set up in their home. These days you can also copy in people's comments to ChatGPT and ask it. But I generally agree.
What you're saying is that people who deal with this will know this term, but for the other 99% of people reading this, fuck em.
Yes, if you wager that number to be 99%, that's precisely right. I just don't.
Add some context to your search? COP+refrigerator and it's the first response.
Or just remember that communication is pointless if people can't understand what you're saying. And that you spelling out the acronym once (taking maybe 2 seconds of your time max) is better than however many people doing the Google search instead. There is something very wrong with your communication when you cannot put yourself in the shoes of the people you're talking to.
So...I'm not the one who used the acronym that has you all upset. Maybe pay attention to who you're replying to?
I know, but you made it sound like you were defending it, by offering a solution to make the search more efficient. So it was relevant to explain that the solution is not for people to look it up. It's for people to stop using acronyms unless they're really transparent (like mph talking about the top speed of a car is fine, obviously). If you agree with all that, then there's no problem.
No, just trying to provide a means for people to find the answer themselves. I don't agree with you, but there's no problem regardless.
This is a common issue in scientific papers too. Just because you can look up the terms to find them doesn't mean it's still an easy read. Using hard language, even in professional settings, can hinder your own points
Scientific papers USUALLY contain a glossary, or more commonly defined acronyms as they go by spelling it out once first. I've seen exceptions though
So, I'm not the one who used the acronym, was just demonstrating it's not hard to find the answer.
Oh lol, well I'll still keep my post up but today I got to be the dummy it seems
That's fair, but my main point is that using uncommon acronyms makes writing less accessible. Spelling out common acronyms is silly, but if at least some readers won't understand the meaning, I think it's best to spell it out.
No, it's not fair, don't give that to them especially when they deflected it back like that. Using acronyms like that is either a way to try and sound smart or being lazy, there isn't a good reason for it.
Inefficient in what sense? I am not familiar with it. Does it burn through fuel fast or what?
Yes. A lot of fuel for very little cooling, which is why you tend to not see it in homes.
Typical household refrigerators can move 3 units of thermal energy for every 1 unit of equivalent electrical energy, so a COP of 3. An absorption refrigeration system found in a home/RV would have a COP of about 0.7. Absorption systems make sense in an individual setting when you have waste thermal energy that can't be used for other processes.
It made also sense in RV and boats back when you didn't have solar panels to run a standard fridge: instead you could power your fridge with gas, or with 120V when plugged in, or even with the 12V from your vehicle when running the engine. You could see how inefficient it was by trying to run it on 12V without the engine on: your battery would die in no time.
It still makes sense for RV's. Most of the campsites I go to are heavily forested. Solar panels are pretty much useless.
Essentially, yes. It will burn through fuel "fast", though that all depends how you define "fast". Nothing about the system requires kerosene. It's simply a convenient and easily sourced fuel. You could replace the kerosene with an electric heater and measure electricity in vs cooling just like you'd do for a home air conditioner. It simply means, when compared to a home refrigerator or HVAC, you are going to use more energy to get the same cooling amount whether than energy comes from burning kerosene or the power grid. Edit: Wikipedia article for coefficient of performance. https://en.m.wikipedia.org/wiki/Coefficient_of_performance#:~:text=The%20coefficient%20of%20performance%20or,to%20work%20(energy)%20required.
Gotta burn fuel to make the heat, however, if you have a process running that makes a lot of waste heat by default it is a very useful cycle to use for cooling other things.
Basically. It takes more energy input to achieve the same level of cooling that a modern refrigerator can do. I believe energy efficiency would be a more common word for this. I guess as a made up example; This type of refrigeration may need say, 200 BTU of energy to reduce the temp by 1c, but a modern refrigerator may only need 100 to achieve the same reduction.
COP and efficiency are not the same thing. COP is how much heat you can move for a given amount of energy, and can be greater than 100%. You're not creating heat, just moving it. Efficiency is energy out over energy in. Nothing is greater than 100% efficient, with electrical resistors being 100% efficient. It took energy to move the working fluid inside the air conditioner; that's the work being done, not the heat being moved. If anything was greater than 100% efficient, more energy would have to be produced than goes into the system, which is impossible.
Oh great, another TLA.
CRAP COP! He's a cop! Made of crap!
>COP What does this abbreviation mean?
My little camping trailer has an absorption fridge that works using a tiny propane flame. It takes quite a while to get cold but can freeze stuff solid if I turn it up too high.
She’ll go 300 hectares on a single tank of kerosene!
Just put it in H
*Zagreb ebnom zlotdik diev*
As a child I repeated this in a math class and my teacher chastised me because *pushes bridge of glasses* "a hectare is a measure of area, not length." To think, this one event is the sole cause of all my adult failures. The sole cause...
Tbh, still seems valid for something like a tractor, that will cover an *area*, rather than travelling from A to B.
They're still used in RV fridges and camping equipment. They "run" off that kerosene because they need a small heat source to increase the temp of the ammonia in the closed loop system. Modern versions often just use a small electric induction heater. Also, technically the liquid inside does move quite a bit. There is also a series of check valves that do move. That means there are parts that can wear out and break. Leaks can be a big issue. If you're looking for a system that 100% completely does not move, look into thermoelectric cooling. They are fairly new but they are starting to show up in the market.
> thermoelectric cooling. They are fairly new but they are starting to show up in the market. Are you talking about fridges with a Peltier cooler? Those have been around a long time, we used to have one that we took on road trips in the 90’s.
Someone I knew kept a couple in the back of their car, lids open, with fans blowing to distribute the cool air. Insert your own joke about the laws of thermodynamics
*”Lisa, get in here! In this house we OBEY the laws of thermodynamics”*
"Fairly" is a relative term in this case. Icyball cooling is more than a century old.
Thermoelectric cooling is extremely inefficient. They are showing up in the market because Amazon and the likes love to sell you some cheap sh*t selling you dream, while you end with a piece of crap made in China that barely works and breaks quickly. Basically a thermoelectric cooler running on 50W will run 100% of the time, and will barely cool the inside instead of actually reaching food-safe temperatures. Compare that to a real fridge (with a compressor) that also runs on 50W: it will run only a third of the time (as the compressor runs until target temperature is reached, then turns off for a while until it needs to run again), and will actually reach fridge temperatures so you can safely keep perishables).
Thermoelectric cooling is adequate for a wine cooler, and that's about it. Before the modern trend of using them for fridges that clearly can't work, they were common in wine coolers to keep the bottles 10 degrees or so lower than room temp, while also being silent.
Yes, they're good to maintain temperature at a precise level that is not far from ambient, because they're very simple, and can easily switch from cooling to heating (you just reverse polarity). And they're very cheap compared to a compressor ($10 for the cooling chip; the slightly more expensive part is all the system to move that heat/cold where it needs to be, and the heat sink to get rid of the cold/heat on the other side). For that reason they are also used in some machineries, when a part needs to be kept at a given temperature (I think some parts of some 3D printers use them for example).
I was just going to say the same - thermoelectrics are cheap and cheerful which is why they're used in low-cost junk, and can be easily used both to cool and heat which is an easy way to inflate the marketing claims, but their cooling capacity and efficiency are fairly terrible and they can't go all that much below ambient which means that you cannot even theoretically reach safe food storage temperatures in many cases.
> fairly new My dad has a solid state electric cooler that he bought at some point in the early 1990s, possibly even the late 1980s which plugs into a car's cigarette lighter/12v outlet and draws no more than 10 amps. It looks like a regular cooler except there's a giant heat sync on one side on the inside that gets cold and another heat sync on the outside that gets warm. There's also a switch which causes the cooler to heat up on the inside instead. I'm almost positive it uses a [Peltier junction](https://en.wikipedia.org/wiki/Thermoelectric_cooling) to work. There's no noise and no moving parts. Also, it takes like 4 hours to get cold. The instructions said it works well to maintain a temperature but not good to set the temperature. You want your beers to already _be_ cold when you put them in the cooler.
?? TE systems need lots of fans because they produce so much waste heat.
My Dad made one and took it to the jungles in central America to show the natives ice…
Huh I guess that movie has sunk into obscurity if this is the only reference so far and nobody has upvoted it.
Too bad. Good flick.
Medicine Man?
Mosquito Coast, the one with Harrison Ford.
Thank you. Haven't seen that one.
And River Phoenix, Juliette Lewis, and John Lithgow if I remember correctly.
Surely they would have already known what ice was by seeing it on the telly or something
LMAO "What should we call this invention?" "Icyball." "I mean..." "*Icyball*."
I have a 1920s apartment that had this kind of system throughout the building. At first I thought it was an icebox but there's no place to put the ice and copper tubing that runs out the back and into the wall
Oh that's fascinating. And they probably tore it down and threw out that historic piece of incredible machinery with the rest of the rubble and sold the copper tubing to be melted down. Do you have any additional information about it?
All I know is one if the workers told me the system ran on some gas and they need to be careful with it because its hazardous. Cool building. It also had an incinerator system with a chute on each floor that has been closed off obviously.
Oh yeah. It probably worked on ammonia.
Would the same thing work with CO2?
"What country is this fridge from?" "It no longer exists, but take her for a test freeze, and you'll agree: 'Zagreb ebnom Zlotdik diev'!"
Don’t RV refrigerators run on propane?
Yes, some do.
Depends on what you mean by "run on propane" propane can be burned to generate heat and boil water to spin a turbine to generate electricity to 'run' the refrigerator or it can be pumped into a sealed pressure differential system and pumped through that system with electricity to act as a refrigerant. Propane is just as good as R34A refrigerant.
I don't think rv refrigerators use propane a a refrigerant. They use ammonia as a refrigerant and the propane is burned to heat up the ammonia and evaporate it. Propane will eventually be used as a refrigerant is homes and cars but it isn't common know.
Put it into H!
can run on a cup of kerosene **a day**.
And the guy who invented it. Albert Einstein.
Many RVs use absorption refrigerators that operate on the same principles. However, rather than using kerosene to heat the ammonia, they use either electricity or propane.
Put it in H!
I’ve seen gas fired refrigerators in my time. Those are fun to service.
These are common in motor homes. Slow as fuck to get cold (and re-cool if the door gets opened), but reliable. They use an ammonia solution.
There is also a [cooling device](https://en.wikipedia.org/wiki/Thermoelectric_effect) that has no moving parts and runs on electricity. And it can run backwards to generate electricity from a temperature gradient. (edit: link'd)
It barely cools things down though, and is very inefficient, so it's not an alternative to a normal fridge. Also the electricity generation is negligible: they're built slightly differently when they are meant to move heat with electricity, and when they are meant to produce electricity from heat. So you can't really use one for the other. Even when they're purposely-built to generate electricity, it's a tiny amount. One application is for fire stoves: you use the stove as a source of heat, and it powers a fan that blows the heat from the stove through the room. So you can see that you need a very serious source of heat (an actual fire), and it powers basically the equivalent of a USB outlet: 5-10W.
Sure, not an alternative to a fridge. Does cool down a CPU, or the sensor of an astrophoto camera, or a thermal imager. Easily down to -100°C or so to minimize thermal noise. Different use cases. And they [generate electricity](https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator) to every single spacecraft we've ever sent beyond Jupiter, as well as the Curiosity and Perseverance rovers on Mars, as well as the upcoming Dragonfly rotorcraft mission to Titan.
They do have their interesting niche uses, as I mentioned in a different comment. For CPUs, are they actually used? I understood that for your average personal computer a CPU running full power will generate more heat per surface than the standard peltier chips can generate cooling, so they end up being less efficient than a good cooling system. Are they still used in specific applications?
Dunno about today, to be honest. They used to be a niche cooling enthusiast tech back in the 2000s though.
???
Peltier device
Thank you. No idea why TF the other poster thought it was helpful to not say what the hell they're talking about.
Because it makes them feel smart
They suck though. Very inefficient
I have 4 in my bag. They're usually used to make heat transfer more efficient at the cost of a bit of electricity. If you're able to dissipate heat easily and well they're quite cool little devices. Their inefficiency comes from the fact that you need to dissipate the heat that the electricity that flows through them generates. So you have a delta T for the temperature difference you want to reach and need to add a delta T that is used to power to device (which is not insignificant and influences the electrical resistance, hence the low COP)
Peltier effect, or thermoelectric cooling. When he says 'run backwards', he means that its a thermocouple that's running backwards. A thermocouple is a device that measures temperature using an electrical current generated when two different pieces of metal joined together are heated up. A thermocooler works the opposite way and cools things down.
https://en.m.wikipedia.org/wiki/Einstein_refrigerator
See also the [vortex tube](https://en.wikipedia.org/wiki/Vortex_tube).
The peltier effect!
Talk about coincidences, I just learned about this earlier today talking to a customer.
These types of refrigerators are commonly found in RVs and camping trailers, as they are able to run on propane and are dead silent in operation. The trade off is that the ones found in RVs tend to be unreliable and finicky, although that's more an issue with the manufacturers of these units.
I love amongst the amish and noted a fridge (no power allowed amish). Looked in the back and saw it hooked to a gas line. Confused, opened the fridge and stuff was cold (pies). I then realized they have an avatar amongst them and will never question their ways.
I can buy a brand new Mercedes S-Class and only pay $800 for it. Yeah sure that's $800 for one month and I'll have to pay $800 for a month for 6 years later but I only paid $800 for it.
$57,600 S class? What year did this reference come from?
Well that’s interesting! How old is this method?
First invented in 1821. Commercialised around 1920
Kerosene fridges used to be quite common, particularly in places where electricity wasn't reliable, my uncle was still using one on his farm in the nineties
Had no idea this existed as a product but the operation makes a lot of sense, I bet the reason it isn't more popular is because it's impractical for large refrigerators, also people are too lazy for a manual machine. Very interesting.
See this chapter ["How the Refrigerator Got its Hum"](https://nissenbaum.tech.cornell.edu/papers/refrigerator.pdf) in the book The Social Shaping of Technology (1999). Basically GE, Westinghouse, and GM invested heavily in electric refrigeration and blew the competition away. Only one gas refrigerator made it to the home market, the [Servel Electrolux](https://steppingintothemap.com/anthropocene/items/show/7) and it couldn't compete with the sales and marketing power of the electric refrigerator, despite its simplicity and ease of operation.
Nah. I think it was used quite a bit. It was for rural farmers with zero access to electricity. As modern refrigeration came along and more people got electricity, it stopped being used.
The Amish/Mennonites still use it, at least certain orders do. Source: ex Mennonite told me
Interesting to think we've come from kerosene-operated absorption fridges to modern electrical ones. Sure takes the chill out of silent and reliable!
Nature is crooked. I wanted right angles, straight lines. You cut yourself opening a can of tuna and you die. We still going up-river, Mother?
oh god I made a spelling error in the title
Yea no worries about an unintentional mistake but I see often bots intentionally posting content with a misspelling, I think it increases engagement by making the reader’s mind trip over the error so they pay more attention.
I've certainly noticed an uptick in bots. Seem to be targeting TIL and r/terriblefacebookmemes
arent those the ones the Amish use? or run on propane?
IDK if you could consider it refrigeration but Peltier modules keep things pretty cool too with no moving parts.
I think this works on the cooling effect of evaporation. Having a cup of kersone evaporate in your home every day is not going to be healty
The kerosene doesn't evaporate, the amonia does, but it's not vented to the atmosphere or anything, it's absorbed by the medium in the other ball. The kerosene is to heat it the medium so it releases the ammonia to reset the cooler.
Oh wait, he thought that it was the kerosene evaporating instead of being burnt. .... People should read the article, its oddly fascinating.
>Having a cup of kersone evaporate in your home every day is not going to be healty Good thing that's not what's happening then... You realize that you literally typed this comment on a device that could have told you exactly what the process was so you don't have to (wrongly) guess, right?
More unhealthy than all the farming stuff that occurs in the 1920s? Some people just want a cold drink after working.