>TIL almost 75 percent of the refrigeration and air conditioning sector can be converted to natural refrigerants, such as ammonia
It's certainly a point to be made, but you would probably be better off not making *ammonia* of all things the poster child of the argument. There are good reasons why it was first used as a refrigerant and there are *even better reasons* why it was abandoned outside of fringe use cases.
Most (if not all) industrial refrigeration systems run on ammonia today. Meat processing, food packaging, medical, etc. These systems are typically running 10,000lbs or more of ammonia.
We have a meat packing plant nearby that suffered an ammonia leak a few years back. They created a two mile quarantine zone until they had someone who could approach and get it under control. It smelled awful for hours.
My uncle had a fish storage warehouse at the warf when I was a kid. Their refrigeration used ammonia. They had a shed up on the shore with space suit looking sealed suits for if there was a leak. Never had to use them that I know of but I liked to climb in them and play spaceman when I was little.
Yes.
Methyl Mercaptan is added to fuel gases to make them detectable.
It was chosen because it smells similar to 'town gas', which was a mixture of gases produced by the [gasification of coal](https://en.wikipedia.org/wiki/Coal_gasification#Process).
>It was chosen because it smells similar to 'town gas', which was a mixture of gases produced by the gasification of coal.
No, it was chosen because we can detect the odor at just 1 part per *billion* witch is amazingly sensitive for the human nose... And that it mixes well with methane instead of dropping out.
Its added at a level of about 1~10 part per million to natural gas, meaning you can detect natural gas leaks long before it hits 1% (Natural gases flammability limit is 5~15% in air)
A quick google about coal gas smell finds:
>Coal gas naturally contains hydrogen sulphide which smells like rotten eggs. However in the early years that smell was often insufficient to warn user of leaking pipes, so the gas was given additional substances, such as mercaptan, to make the smell more pungant.
Its not that they added Mercaptan to natural gas to make it smell like coal gas, its that they where already adding Mercaptan to coal gas to make it smell enough to detect leaks and continued the practice with natural gas that had no/little smell.
The lethal concentration for ammonia is only 500ppm. It gives severe issues long before that. So we should be very glad it can be detected at much lower concentrations.
That said, that's outdoors. Indoors, you might not be able to get away.
Meat packaging plants have employees. I suspect the person I'm responding to would have mentioned the fatalities instead of smell if there were fatalities.
Employees with training, PPE and possibly glycol loops as well, I would imagine.
All because ammonia is so dangerous indoors. Why do you think freon was invented in the first place?
You're way over imagining how dangerous ammonia is in industrial applications then. Most of the employees probably wouldn't have know about it until they smelled the leak, let alone been trained to deal with the leak.
That's such a massive amount that a leak would require an evacuation of several miles around the plant since ammonia vaporizes easily and is extremely toxic
The ammonia used in industrial refrigeration is also in anhydrous form (not diluted in water, like household cleaners are). Water is an excellent absorbent of ammonia, *including the water in your pores*. Not fun stuff to be around without the proper PPE.
I used to work a job where ammonia was used to modify the pH of a solution. Had to wear a full face respirator and long gloves covering the whole arm. Exposed skin would start to feel like it's burning from the fumes.
Its the water in your lungs that is the killer with anhydrous ammonia. Every year there are stories of semis crashing with tanks of it, or a major leak at a fertilizer place that kills several people.
Those systems are almost always indirect systems with a glycol loop inside the building requiring the cooling. It's not too often I see ammonia INSIDE a warehouse/food production site anymore.
The majority of the ice industry uses ammonia with no glycol loops. Actually, glycol loops aren’t used at all in this industry. Occasionally Freon is used but it’s not as efficient as the ammonia so it’s only seen in small plants.
There are many safety requirements to have ammonia on site (ventilation/room changeover requirements, ammonia detection, etc) and the external equipment is usually locked up heavily to prevent methheads from trying to steal the ammonia.
Yeah I imagine the lower temps for ice require highly efficient cooling systems. What kinda temps are you running inside the ice mfg/warehousing spaces? Are y'all running ammonia on transport vehicles as well? Or can you switch refrigerants b/c size. I'm not too familiar with the ice industry.
Small stuff like merchandisers/trucks use whatever the current reg says is best which annoyingly changes quite a lot so whatever you find in the field could be running anything, especially because users will modify them so all their equipment runs on one refrigerant…I guess it’s usually older refrigerant when they do this? Ammonia can’t be used not because of safety (amount for small/portable is pretty small) but theft. Propane/butane scares people too much despite being quite efficient and safe.
I'm certain that's either legacy infrastructure/equipment, (borderline dangerous) cost cutting, or both. There is no way a modern engineer looks at that and, in good faith, says "good idea".
Edit: OK I get it, it's cost cutting, not legacy. Please stop arguing that it's fine just because many people are doing it. That's not a good argument.
Ammonia is great for large scale refrigeration. It's cheap and efficient. Large systems can also have better maintenance than small systems like in residential use.
Ammonia is toxic to humans, doesn't deplete the ozone, and doesn't contribute to global warming if it is released. The systems are cheaper to build and more energy efficient to run, and deaths from ammonia exposure related to refrigeration are extremely rare.
They're not new either, propane and butane have been used as refrigerants for a long time too.
Nontoxic, non flammable, cheap, efficient, non ozone depleting. You can get 4 out of 5 but nothing so far is 5 out of 5.
Most chemicals found in an industrial building could also be described like that. Should we shut down every factory that uses welders since they have gas tanks that could explode?
Sometimes risk is necessary and reasonable to take.
I’m an industrial refrigeration design engineer. You are wrong. It is the most common refrigerant used in large industrial refrigeration plants in Europe. It’s is even more common than it used to be due to F-Gas laws.
I worked for the Coors brewery in Golden for almost a year in the early 2000s. They claimed at the time to be the US's 2nd largest user of anhydrous ammonium, after the Tropicana juice plant in Florida. So every day on my way to my work station I'd pass by a network of huge criss-crossing pipes filled with pressurized ammonia, and covered in asbestos insulation.
Fun stuff!
https://iiar.org/ This used to be an association for ammonia refrigerants and now it’s all-natural, as CO2 and other refrigerants are being more widely used.
At work I was looking at a heat pump shop drawing and saw 'R-744 [CO2]' and was like "wait what?"
"CO2 is a refrigerant" was my fun fact for that week.
It’s used in some niche cases. Mostly air-source heat pumps for domestic hot water from what I’ve seen. It has a different performance curve than traditional refrigerants and needs to be at much higher pressure which means SS piping over copper
Yeah I did read a bit into it. At first pass it seems like such an odd choice too. It doesnt even have a liquid phase at atmospheric pressure so it makes sense that it has to be much higher pressure to be a refrigerant.
If you want to see a horror show look up 'dangers of anhydrous ammonia' I lived in farm country and my grandfather sat me down and said if you see a farm truck wrecked and they were towing a tank and it looks like clouds or smoke. You throw your car in reverse and get away and call 911. If someone is laying out in the road or is in the car they are probably dead hit reverse call 911.
Many years ago I was in a restaurant that had a minor ammonia leak in their freezer. A hundred panicked people ran chocking and gagging into the street. Fine for industrial applications, not domestic.
I just saw our local supermarket said they'd shifted to natural ones and looked up what that meant
I knew already the huge issues the synthetic ones cause so was intrigued
I am a HVAC tech and let me tell you, we've tried a whole lot of things for refrigerants, and there's a very good reason WHY we don't use ammonia or hydrocarbons in most refrigeration or air conditioning applications.
It's because it kills people. And the ones that aren't immediately lethal? Look up an MSDS for R32.
Not really - leaks typically happen at heat exchangers and not the piping, and covering a heat exchanger with something like that would cause it to stop working
Natural does not mean safe or efficient. Arsenic is natural. Asbestos is also natural. Neither of those things are great in the grand scheme of things.
If we can figure out some material sciences on making asbestos less prone to throwing airborne particles all over then that shit will be used in everything again. Because it works. Although I know too many people who have died from unknowingly working with that shit and breathing it in. One of my best friends is currently suffering from exposure as well because the company he worked for didn’t provide them PPE and bypassed inspections while lying about there not being asbestos so it was “safe” and it’s such a shitty thing to see.
> Like organic heroin.
Or 100% natural arsenic.
My family has long collected oddities. (One thing in our collection is a Mastodon molar)
Pre-9/11, I brought in an arsenic crystal to elementary school for show and tell with the school's permission.
I don't even know what "natural" means here. It's not like there's some free-range artisanal ammonia out here - ammonia at any kind of large scale is created through an industrial process like any other refrigerant.
Haber process of taking atmospheric nitrogen and combining it with hydrogen gas was a breakthrough for creating chemical fertilizers as well as much more nefarious things. Pretty sure a variant is still used.
With multiple redundancies and containment units. I work in HVAC for these systems Ammonia is good; except when it gets out. Which is why the industry is trying to find better and safer refrigerants to replace R410 that can be used without these redundancies.
R-454B is expected to be this replacement.
R290 is also common for small appliances and industrial uses, but it's very flammable. R744 is gaining some popularity but requires high system pressures.
I’m hoping for R744, but selling gas type pipe and fittings gets expensive for the poundage needed.
Doesn’t help that the industry is moving slower due to the big storms we’ve been having.
CO2 solves both the greenhouse gas and toxicity problem.
Sure, it is a greenhouse gas but with a global warming potential of 1, v in the hundreds or thousands for other refrigerants
Yes, it’ll also kill you in a high enough concentration but you need A LOT of CO2 for that. I’m not going to do the math but I’d be surprised if the amount in any household refrigerant would kill anyone. Unlike CO it also flushes out of your system very quickly.
I did my master's degree working with the people who pioneered co2 as a refrigerant, and back then, we also looked at using it in cars where it could be dumped into the engine bay in case of fire. Slightly amusing fact.
And Albert Einstein patented a refrigerator that was safer than traditional ones.
[https://www.invention.si.edu/einstein-szilard-refrigerator](https://www.invention.si.edu/einstein-szilard-refrigerator)
Butane is R600, I see it being used all the time in a lot of smaller refrigeration tasks like those Red Bull fridges at bars and restaurants.
I like the technology and effectiveness behind phase change refrigeration personally, (even if it isn’t always as energy efficient), as it tends to have a larger temperature range that it is capable of being effective in. My understanding is that ammonia based refrigeration was an evaporative cooling technique. Or are there phase change ammonia based systems too?
Apologies for doing a US Defaultism, but the United States are moving to R-32 and R-454B in residential systems next year. I could be wrong about the actual chemical makeup, I’ve been led to believe that it is a propane based refrigerant, and even if it isn’t propane based it is still mildly flammable with a low flame speed.
They aren't propane based, but they are mildly flammable. The difference is they are much harder to ignite than propane. For example, a spark won't ignite those but it will ignite propane. That would make propane very dangerous in both homes and cars.
I see, I know they’re going to start enclosing contractors, adding a fan cycle before startup, and some sensors. My knowledge is all second hand from the supply house for know, but we’re having a CE class as a company in the fall.
It’s an A2L and they had to come up with the L designation pretty recently because of how lightly flammable these gases are. Yet the entire industry is freaking out about it.
Not too many tools are going to change. Maybe a set of gauges.
Supply houses are actually impacted because they now have to inventory 1-2 different types of refrigerant as well as maintain stock of 410a.
They have product inventory they desperately want to get rid of as well.
I promise refrigerant change is not a money making scheme devised by big HVAC.
No I understand it’s a regulatory thing and not a money making scheme, they’re (supply houses) selling us (hvac companies) on new guages, new vacuum pumps with a different style motor, press tools and heads for linesets because they’re saying we can’t braze anymore, little adapter for the refrigerant bottles, and I think that’s most of it. Supply houses are pushing those things pretty hard
I don't understand your comment. Really I don't understand if you're being sarcastic or not.
Propane is a great refrigerant, people are afraid of it because it is flammable. Specifically it was considered a replacement for R-12 in cars but was ultimately abandoned in favor of R-134a. Why is having a flammable substance in vehicles so dangerous given that gasoline is highly flammable? This same argument goes for the use of hydrogen as a fuel source in combustion engines.
It's not used in vehicles because the refrigerant lines can get ruptured. Vehicle refrigerant lines are made of fairly soft tubing. Cars have blown up in what would otherwise be uneventful front end collisions because somebody cheaped out and put propane in their AC system.
Gasoline is run through soft rubber hoses and pumped at high pressure from the rear of the car. The argument seems silly to me that there is a refrigerant that is readily available, and relatively safe, while definitely much safer to the environment yet people are afraid to use it because it's dangerous. While we have gasoline which is highly flammable and difficult to extinguish once ignited already in the vehicle.
Upper and lower flammability limits for propane and gasoline are similar but gasoline has a much lower vapor pressure it is far less likely to be a vapor at atmospheric pressure than propane which is a gas at atmospheric pressure
You're forgetting how the AC system is set up in a car, and that changes everything. There are AC lines and a condenser on the front of every car, either right in front of or behind the radiator. So the AC system is involved in, and compromised by, almost every vehicle collision. This system also runs into the passenger cabin, so if it catches fire or explodes it's going to directly expose the occupants.
The fuel system is not usually affected in this way, so it has a much lower chance of causing a problem, and it's completely separated from the passenger compartment of the vehicle.
>Why is having a flammable substance in vehicles so dangerous given that gasoline is highly flammable?
For a lot of reasons.
Propane at ambient temperatures is a gas and gasoline/petrol or diesel are liquids. The vapors are significantly more flammable than the liquids. The flashpoint of propane is lower than the lowest temperature recorded on earth in human history.
A typical fuel system in an ICE has the reservoir(gas tank) on the opposite end of the vehicle from the engine where combustion occurs with check valves separating the supply and functional end.
A simple HVAC system doesn't have a reservoir. All of the product is in circulation and the system relies on compression to function. Propane remains a vapor throughout the entire process involved in cooling, meaning that it is a flammable vapor under compression throughout the whole system, which is closed and has no vent.
Gasoline and diesel at 1 atmosphere are flammable, not explosive. The explosion that occurs in the cylinder of an engine is due to the fact that the vaporized gasoline is compressed and ignited with a spark. This exothermic/exobaric reaction is designed and contained within a heavy metal cylinder with a designated exhaust port.
Simply put: Gas is flammable. If your engine catches fire then the fuel inside it will explode, but the fuel in your engine is mostly inside a vessel designed to contain said explosion. If the fire reaches the gas tank it will explode, though the tank is designed to not contain much pressure leading to a low order detonation. If there is ignition inside an HVAC system using propane as coolant, the system is already pressurized. If a flame manages to flash into the system it will propagate rapidly and explode.
In the event of a collision a leak of the HVAC system in a car is almost guaranteed which could cause the above situation.
Propane is an excellent coolant for systems where exposure to a flame/heat source during a leak isn't a likely concern. Which is the exact opposite condition of what occurs underneath the hood of a car.
Source: Former explosive technician and HVAC supplier.
I remember there was a plane crash bc the fuel vaporized and became way more flammable (there was an unknown design flaw) and a small spark caused it to explode in flight
TWA Flight 800.
I think the theory is that the climate control (ironic given this post) was located directly under or beside the center wing tank and, since the flight was delayed, was running more than usual. That combined with the weather, heated up the fuel and allowed a spark to easily ignite the vapors within the tank.
The crash led to the widespread use of inerting agents like nitrogen in fuel tanks.
Thank you for your well thought out response. Most people just downvote and move on.
The argument I have is that gasoline is a lot more dangerous than people give it credit for due to complacency. I think with the proper refrigerant lines a safety margin could be built in. But I don't see it eve happening.
>I think with the proper refrigerant lines a safety margin could be built in.
Not in a machine that regularly travels 70mph where a collision with other machines of equivalent masses is a concern you have to factor in.
I knew I had read about propane being used already in automotive applications. R290 is refrigerant grade propane and is being used in automotive applications. There are a lot of sources stating that it will be wider spread in the future as well.
> If a flame manages to flash into the system it will propagate rapidly and explode.
There's no oxygen inside the system. If the engine catches fire, the AC system will get hot, exceed its pressure limit, and burst- or blow out a safety valve. In the case of a safety valve, that's a powerful additional flame, in a location chosen for safety, in a car that was already burning. If the system bursts, that's much worse, but it should be unilikely.
Yes in a closed system it won't ignite due to vacuum. But in a crash where everything starts to bend and break, the lines are going to be compromised before any type of safety valve can evacuate the refrigerant. Two breaks with air entering the suction line and a flame entering elsewhere, especially the discharge line, then you've got a bad recipe.
I'm sure people smarter than me could design fail-safes to mitigate the danger, but that would be a more complicated(expensive) change and at the end of the day you're still introducing a hazard by putting another flammable material into the equation.
the propane vapor concentration needs to be between about 2 and 10 percent for propane to ignite in normal air, which is roughly 20 percent oxygen. Outside these limits there isn't enough propane or there isn't enough oxygen and there is no ignition at atmospheric pressure.
I used propane in my old ass truck because I couldn't find R12, and I didn't want to shell out the money to replace the system to R-134a. It worked great.
Not to mention that hog farms create an enormous amount of extremely natural ammonia that is a huge environmental problem for groundwater and surrounding fields.
Yes but if there’s a leak it won’t destroy the environment. Synthetic refrigerants are typically way worse for the ozone and sometimes for greenhouse gases than natural refrigerants.
Yeah, but methane is lighter than air, while propane is heavier. The general effect here is that a slow methane leak will simply escape the structure, while a slow propane leak might find a deep well somewhere (e.g. basement) to collect until it becomes a serious problem.
This is also why venting a house that has had a propane leak is typically such a PITA compared to one that had a natural gas leak. Propane tends to form hidden pockets that resist simple ventilation techniques (i.e. shut off the power and open all the windows/doors).
A lot of fridges use flammable refrigerants now, but the quantity is relatively small (less than a pound of gas). But yeah, could do serious damage in a small area.
Mine uses 65 grams of isobutane, not enough to attain an explosive concentration in a kitchen.
Inside the fridge itself is another matter, you pretty much just have to trust them that they use the right switches and connectors that don't spark. It would have been better if they could cut the fill to 30 grams or less then it wouldn't even be able to exceed LEL inside the fridge.
My new fridge uses isobutane (r600a). 65 grams of it (2 ounces).
It’s really a non issue, it isn’t enough isobutane to create an explosive mix in a kitchen. LEL is about 1.8% by volume which works out to those 65 grams being non explosive if mixed with over 1.4 cubic meters of air
Inside the fridge itself, an explosive concentration is possible but there are no spark sources (the switches are all encapsulated when using flammable refrigerants).
edit: and as far as the inside of the fridge goes, it is primarily a matter of good ol "you got to use the right components" engineering. Connectors and switches that don't spark. Obviously you can't have lightbulbs in sockets or regular switches or otherwise build it as if it was R134A
Fridges are at lease on the inside of the wall in a room that probably has a smoke detector.
In the walls lets the problem (remote as it is) get big before you may notice.
I see people literally filling up a tank inside their car with highly flammable liquids before heading out on the road at 80mph, just a few feet away from other people doing exactly the same thing, but going the other way.
Nutcases the lot of them.
That starts on January first. Both new refrigerants that will be used are part propane and identified as mildly flammable. Commercial appliances now use refined pure propane and require us to use special recovery machines when removing refrigerant for repairs.
Evaporator coils will also require a built in leak detector. But that so far hasn’t been sorted out by our manufacturer which is Rheem.
Propane is not “mildly flammable”. It’s an A3. The new refrigerants are A2Ls and they are very difficult to make burn. Neither R-32 nor R-454B contain propane - they are synthetic chemical compositions.
Which is precisely why it is isn’t used much anymore outside of specialized use cases like ice rinks.
Just because it’s naturally occurring and not a greenhouse doesn’t make it safe.
They still use ammonia for cold storage, food processing and freezing. Some places use liquid nitrogen to quick freeze food, but that is extremely expensive and not as efficient as using ammonia freezers.
There are berry processing plants that use ammonia freezing tunnels to instant quick freeze their berries and keep them in cold storage.
Ammonia is dangerous, that's why those places have to have people that are certified and trained to handle ammonia. There's a place that uses 9000 lbs of ammonia for their processing plant. They have safety measures in case of a leak. Like the vacuum the ammonia that's in the system and transfer it to a dilution tank to keep it from spreading.
Same way they handle natural gas, make it smell horrible so it's easy to detect leaks. Unlike natural gas, you don't need to add an odorant. It smells awful on its own.
You can be exposed to an ammonia leak for half an hour without lasting health effects though. Not like you would want to, again, it smells awful.
When you walk into an area with an ammonia leak, it feels like you can't breathe. It feels like the air is being sucked out of your lungs. You panic and scramble to get back to good old air.
Ammonia combines with moisture in the lungs and forms ammonium hydroxide, which is the ammonia used for cleaning. It would be a horrible way to die.
When it happened to me, I was outside, it was a very small leak, so I was able to get away.
0/10. 0 stars. I do not recommend .
You're in an area with an ammonia leak every time you use ammonium hydroxide to clean. It is not stable at room temperature.
What you're describing probably wasn't a small leak, maybe in the [300 ppm range?](https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://teamster.org/sites/default/files/ammonia.pdf&ved=2ahUKEwiCitOb7L-GAxUMOUQIHbRhHekQFnoECBUQAQ&usg=AOvVaw1_PPDPW2QNF3JlQZpuR--J)
I'm skeptical the amount you would have in a refrigerator would be enough to make a kitchen unsafe if it all leaked out, let alone a whole house.
Gasses dilute as they spread.
I work in a cold plant and they use ammonia here for cooling. It's great except when it leaks cause its pretty poisonous and we have to have power engineers on hand at all times to deal with it in case an oopsy happens. I don't know if freon is poisonous but if it is I assume it's not as bad.
Common freon 12/22/134/404 etc isn't poisonous but it's way heavier than air and will asphyxiate you in an enclosed unventiated space.
And if it hits an open flame all bets are off, lots of horrible shit coming from that reaction.
I heard a story where a theater was using an old 1950s era refrigerator as a stage prop. One day the refrigerator leaked out all of its ammonia and the whole building had to be evacuated. It smelled like cat pee.
If you live near any large facility that handles food, I've got bad news for you. A lot of supermarkets use ammonia systems to keep their meat/dairy cold as well.
The problem is that natural refrigerants are by and large toxic or explosive. So, leaks that inevitably form have the potential to severely injure or kill homeowners. There may be ways to help minimize this risk but they all involved increased cost and complexity
> Natural refrigerants are preferred actually in new equipment to their synthetic counterparts for their presumption of higher degrees of sustainability.
Lmao citation needed and the sentence sounds like a valley girl with that “actually”
It always bothered me that the amazing contraption that Harrison Ford invented in that movie had already been a viable invention for a hundred years. Ammonia absorption cycle.
Read up on methyl chloride and ammonia and the deaths resulting from early generation refrigerants. There's a reason we went to CFCs in the first place and HFCs now
The amount of uninformed takes on this about ammonia and its uses ammonia is an enormous part of industrial refrigeration. Ammonia is better used for super low applications like cooling syltherm to -30 for reactor cooling in large pharma plants or large freezers for food production it’s used absolutely everywhere. Propane and butane are more used in really small applications like your fridge at home.
Ah yes ammonia,
It's really cool until a fridge starts leaking and kills an entire apartment block.......
What a stupid argument, you can also use petrol as a refrigerant, until it sends the fridge through the fucking roof
You would’ve been better off saying CO2 instead of ammonia. In Europe they’re starting to use a lot of CO2 systems for supermarkets and “small” refrigeration systems
You do know that the rationale for freon-type refrigeration gases is that ammonia is a toxic bomb waiting to go off. Suggest you look up various industrial accidents where whole neighborhoods get gassed
Breaking news: DuPont warns ammonia refrigerators on boats could leak and baby sea turtles could DIE!
The Forest and Wildlife Service will not allow any ammonia refrigerators to be used until their 5-year investigation is complete and the FAA completes their incident investigation, which can only begin after the other one is complete.
>TIL almost 75 percent of the refrigeration and air conditioning sector can be converted to natural refrigerants, such as ammonia It's certainly a point to be made, but you would probably be better off not making *ammonia* of all things the poster child of the argument. There are good reasons why it was first used as a refrigerant and there are *even better reasons* why it was abandoned outside of fringe use cases.
Most (if not all) industrial refrigeration systems run on ammonia today. Meat processing, food packaging, medical, etc. These systems are typically running 10,000lbs or more of ammonia.
We have a meat packing plant nearby that suffered an ammonia leak a few years back. They created a two mile quarantine zone until they had someone who could approach and get it under control. It smelled awful for hours.
The smell is also part of the reason that this was detected early and didn't cause any fatalities.
Those videos of the rooms with major leaks are closer to a spacewalk in my opinion. Shit looks so cool though
My uncle had a fish storage warehouse at the warf when I was a kid. Their refrigeration used ammonia. They had a shed up on the shore with space suit looking sealed suits for if there was a leak. Never had to use them that I know of but I liked to climb in them and play spaceman when I was little.
You can smell it a good while before it becomes a critical problem, thank god. Gives you lots of time to fix the issue.
Isn't that what they do with natural gas? Put in an additive that makes the ordinarily odorless substance stink to high heaven so leaks are obvious.
Yes. Methyl Mercaptan is added to fuel gases to make them detectable. It was chosen because it smells similar to 'town gas', which was a mixture of gases produced by the [gasification of coal](https://en.wikipedia.org/wiki/Coal_gasification#Process).
>It was chosen because it smells similar to 'town gas', which was a mixture of gases produced by the gasification of coal. No, it was chosen because we can detect the odor at just 1 part per *billion* witch is amazingly sensitive for the human nose... And that it mixes well with methane instead of dropping out. Its added at a level of about 1~10 part per million to natural gas, meaning you can detect natural gas leaks long before it hits 1% (Natural gases flammability limit is 5~15% in air)
That, too. But also because no-one had to relearn what 'gas leak' smelled like.
A quick google about coal gas smell finds: >Coal gas naturally contains hydrogen sulphide which smells like rotten eggs. However in the early years that smell was often insufficient to warn user of leaking pipes, so the gas was given additional substances, such as mercaptan, to make the smell more pungant. Its not that they added Mercaptan to natural gas to make it smell like coal gas, its that they where already adding Mercaptan to coal gas to make it smell enough to detect leaks and continued the practice with natural gas that had no/little smell.
TIL! Cheers!
Yep. Ammonia smells like shit all by itself though, so you don't even need to add an odorant.
Yeah, its part of why I thought Ammonia was used in the first place. Its a nice little side bonus in addition to its refrigerating abilities.
And if you got a boner and get a whiff of that stuff it’ll be gone in an instant!
Wasn’t this an episode in avatar as well?
The lethal concentration for ammonia is only 500ppm. It gives severe issues long before that. So we should be very glad it can be detected at much lower concentrations. That said, that's outdoors. Indoors, you might not be able to get away.
Meat packaging plants have employees. I suspect the person I'm responding to would have mentioned the fatalities instead of smell if there were fatalities.
Employees with training, PPE and possibly glycol loops as well, I would imagine. All because ammonia is so dangerous indoors. Why do you think freon was invented in the first place?
You're way over imagining how dangerous ammonia is in industrial applications then. Most of the employees probably wouldn't have know about it until they smelled the leak, let alone been trained to deal with the leak.
Industrial users are very different from home users. Ammonia is very dangerous when it leaks.
That's such a massive amount that a leak would require an evacuation of several miles around the plant since ammonia vaporizes easily and is extremely toxic
The ammonia used in industrial refrigeration is also in anhydrous form (not diluted in water, like household cleaners are). Water is an excellent absorbent of ammonia, *including the water in your pores*. Not fun stuff to be around without the proper PPE.
I used to work a job where ammonia was used to modify the pH of a solution. Had to wear a full face respirator and long gloves covering the whole arm. Exposed skin would start to feel like it's burning from the fumes.
Its the water in your lungs that is the killer with anhydrous ammonia. Every year there are stories of semis crashing with tanks of it, or a major leak at a fertilizer place that kills several people.
Those systems are almost always indirect systems with a glycol loop inside the building requiring the cooling. It's not too often I see ammonia INSIDE a warehouse/food production site anymore.
The majority of the ice industry uses ammonia with no glycol loops. Actually, glycol loops aren’t used at all in this industry. Occasionally Freon is used but it’s not as efficient as the ammonia so it’s only seen in small plants. There are many safety requirements to have ammonia on site (ventilation/room changeover requirements, ammonia detection, etc) and the external equipment is usually locked up heavily to prevent methheads from trying to steal the ammonia.
Yeah I imagine the lower temps for ice require highly efficient cooling systems. What kinda temps are you running inside the ice mfg/warehousing spaces? Are y'all running ammonia on transport vehicles as well? Or can you switch refrigerants b/c size. I'm not too familiar with the ice industry.
Small stuff like merchandisers/trucks use whatever the current reg says is best which annoyingly changes quite a lot so whatever you find in the field could be running anything, especially because users will modify them so all their equipment runs on one refrigerant…I guess it’s usually older refrigerant when they do this? Ammonia can’t be used not because of safety (amount for small/portable is pretty small) but theft. Propane/butane scares people too much despite being quite efficient and safe.
We reviewed training on what to do in our manufacturing plant because of the yogurt producing plant next to us had ammonia refrigerant system
I'm certain that's either legacy infrastructure/equipment, (borderline dangerous) cost cutting, or both. There is no way a modern engineer looks at that and, in good faith, says "good idea". Edit: OK I get it, it's cost cutting, not legacy. Please stop arguing that it's fine just because many people are doing it. That's not a good argument.
Ammonia is great for large scale refrigeration. It's cheap and efficient. Large systems can also have better maintenance than small systems like in residential use. Ammonia is toxic to humans, doesn't deplete the ozone, and doesn't contribute to global warming if it is released. The systems are cheaper to build and more energy efficient to run, and deaths from ammonia exposure related to refrigeration are extremely rare.
You left out "flammable, sometimes explosive."
Most refrigerants are flammable, new ones coming out are even more so
They're not new either, propane and butane have been used as refrigerants for a long time too. Nontoxic, non flammable, cheap, efficient, non ozone depleting. You can get 4 out of 5 but nothing so far is 5 out of 5.
Most chemicals found in an industrial building could also be described like that. Should we shut down every factory that uses welders since they have gas tanks that could explode? Sometimes risk is necessary and reasonable to take.
It just seemed like it should be in there, for completeness. And the gases used for most kinds of welding are inert. It's kind of the point.
I’m an industrial refrigeration design engineer. You are wrong. It is the most common refrigerant used in large industrial refrigeration plants in Europe. It’s is even more common than it used to be due to F-Gas laws.
No, it's not just legacy. Ammonia is a VERY good refrigerant and widely used in industrial refrigeration, including new builds.
I worked for the Coors brewery in Golden for almost a year in the early 2000s. They claimed at the time to be the US's 2nd largest user of anhydrous ammonium, after the Tropicana juice plant in Florida. So every day on my way to my work station I'd pass by a network of huge criss-crossing pipes filled with pressurized ammonia, and covered in asbestos insulation. Fun stuff!
yeah no, dont recommend that to anyone.
https://iiar.org/ This used to be an association for ammonia refrigerants and now it’s all-natural, as CO2 and other refrigerants are being more widely used.
At work I was looking at a heat pump shop drawing and saw 'R-744 [CO2]' and was like "wait what?" "CO2 is a refrigerant" was my fun fact for that week.
It’s used in some niche cases. Mostly air-source heat pumps for domestic hot water from what I’ve seen. It has a different performance curve than traditional refrigerants and needs to be at much higher pressure which means SS piping over copper
Yeah I did read a bit into it. At first pass it seems like such an odd choice too. It doesnt even have a liquid phase at atmospheric pressure so it makes sense that it has to be much higher pressure to be a refrigerant.
If you want to see a horror show look up 'dangers of anhydrous ammonia' I lived in farm country and my grandfather sat me down and said if you see a farm truck wrecked and they were towing a tank and it looks like clouds or smoke. You throw your car in reverse and get away and call 911. If someone is laying out in the road or is in the car they are probably dead hit reverse call 911.
People get real ippity when you tell them that propane can be used as a refrigerant
Works really well, too. Explodes only rarely.
You can find leaks REAL quick
Just picture a car accident. Where every vehicle is leaking 4 pounds of concretrated ammonia.
Cars only hold about 500 grams of refrigerant
Yeah, well, you mom is a refrigerator Alucard! *Runs*
anhydrous ammonia. It wont matter once the lithium-ion batteries rupture though
The experiences from countries with many EVs is that they are less of an issue than fossile fuel fires.
Nonsense you can use conventional firefighting methods on a gasoline fire. Lithium batteries require flammable metal extinguishers.
Many years ago I was in a restaurant that had a minor ammonia leak in their freezer. A hundred panicked people ran chocking and gagging into the street. Fine for industrial applications, not domestic.
Work in an industrial plant that has ammonia systems and take the safety class. You wouldn’t sign up for that to be in your home.
I just saw our local supermarket said they'd shifted to natural ones and looked up what that meant I knew already the huge issues the synthetic ones cause so was intrigued
RV refrigerators commonly run on propane and use both hydrogen and ammonia in their systems.
Any volatile liquid works, really. The fridges at the grocery store near me use cyclopentane.
any gas you can compress should work in theory. Carnot sycle
I'm full time in an RV and all RV fridges are ammonia, or at least they were. Helium is slowly replacing ammonia in RV's and Amish homes alike.
Don't you mean 'fridge use cases?'
A frozen food manufacturer near me used to use ammonia, now they just buy liquid nitrogen and vent it in to flash freeze the food
I am a HVAC tech and let me tell you, we've tried a whole lot of things for refrigerants, and there's a very good reason WHY we don't use ammonia or hydrocarbons in most refrigeration or air conditioning applications. It's because it kills people. And the ones that aren't immediately lethal? Look up an MSDS for R32.
Could you line the piping with a material that neutralizes ammonia? Like baking soda or something like that? So in case of a leak, it's not hazardous.
Not really - leaks typically happen at heat exchangers and not the piping, and covering a heat exchanger with something like that would cause it to stop working
no
Buildings with pressurized ammonia, what can go wrong? /S
Natural does not mean safe or efficient. Arsenic is natural. Asbestos is also natural. Neither of those things are great in the grand scheme of things.
If we can figure out some material sciences on making asbestos less prone to throwing airborne particles all over then that shit will be used in everything again. Because it works. Although I know too many people who have died from unknowingly working with that shit and breathing it in. One of my best friends is currently suffering from exposure as well because the company he worked for didn’t provide them PPE and bypassed inspections while lying about there not being asbestos so it was “safe” and it’s such a shitty thing to see.
Ammonia is way more efficient than freon sometimes 20% more. Ammonia use is enormous in industrial refrigeration.
Ammonia as a refrigerant is the very reason we got freon. Ammonia killed a lot of people.
Safety standards are written in blood.
What is deemed safe for industrial applications isn't usually the same as safe for residential use.
It’s not that’s why it’s not used in commercial or residential
They used to use ammonia until the leaks started killing people. Freon was much safer.
Yeah lol, natural does not always mean better or safer.
Like organic heroin.
> Like organic heroin. Or 100% natural arsenic. My family has long collected oddities. (One thing in our collection is a Mastodon molar) Pre-9/11, I brought in an arsenic crystal to elementary school for show and tell with the school's permission.
Opium?
I prefer free range heroin
Yea I like my #4 lion stamp to be pasture raised.
I don't even know what "natural" means here. It's not like there's some free-range artisanal ammonia out here - ammonia at any kind of large scale is created through an industrial process like any other refrigerant.
Haber process of taking atmospheric nitrogen and combining it with hydrogen gas was a breakthrough for creating chemical fertilizers as well as much more nefarious things. Pretty sure a variant is still used.
(Snooty voice) "Well, when I need mercury, I always prefer organic"
Asbestos is a good example
should be top comment. as someone who used to be an hvac worker, ammonia scares me.
Except ammonia is still widely used, probably the most common industrial refrigerant
With multiple redundancies and containment units. I work in HVAC for these systems Ammonia is good; except when it gets out. Which is why the industry is trying to find better and safer refrigerants to replace R410 that can be used without these redundancies. R-454B is expected to be this replacement.
R290 is also common for small appliances and industrial uses, but it's very flammable. R744 is gaining some popularity but requires high system pressures.
I’m hoping for R744, but selling gas type pipe and fittings gets expensive for the poundage needed. Doesn’t help that the industry is moving slower due to the big storms we’ve been having.
Absolutely. But not much used for Billy Bob Jim's 30 year old non-maintained trailer home A/C, picked because it was the cheapest available.
CO2 solves both the greenhouse gas and toxicity problem. Sure, it is a greenhouse gas but with a global warming potential of 1, v in the hundreds or thousands for other refrigerants Yes, it’ll also kill you in a high enough concentration but you need A LOT of CO2 for that. I’m not going to do the math but I’d be surprised if the amount in any household refrigerant would kill anyone. Unlike CO it also flushes out of your system very quickly.
I did my master's degree working with the people who pioneered co2 as a refrigerant, and back then, we also looked at using it in cars where it could be dumped into the engine bay in case of fire. Slightly amusing fact.
Yeah it does REALLY solve the flammability problem
And Albert Einstein patented a refrigerator that was safer than traditional ones. [https://www.invention.si.edu/einstein-szilard-refrigerator](https://www.invention.si.edu/einstein-szilard-refrigerator)
Propane is another good refrigerant! Surely we can see why synthetic refrigerants are used?
Butane is R600, I see it being used all the time in a lot of smaller refrigeration tasks like those Red Bull fridges at bars and restaurants. I like the technology and effectiveness behind phase change refrigeration personally, (even if it isn’t always as energy efficient), as it tends to have a larger temperature range that it is capable of being effective in. My understanding is that ammonia based refrigeration was an evaporative cooling technique. Or are there phase change ammonia based systems too?
There are phase change ammonia systems but they're typically used for heavy industrial applications.
And the US is going back to it next year! ETA: location
Who is?
Apologies for doing a US Defaultism, but the United States are moving to R-32 and R-454B in residential systems next year. I could be wrong about the actual chemical makeup, I’ve been led to believe that it is a propane based refrigerant, and even if it isn’t propane based it is still mildly flammable with a low flame speed.
They aren't propane based, but they are mildly flammable. The difference is they are much harder to ignite than propane. For example, a spark won't ignite those but it will ignite propane. That would make propane very dangerous in both homes and cars.
I see, I know they’re going to start enclosing contractors, adding a fan cycle before startup, and some sensors. My knowledge is all second hand from the supply house for know, but we’re having a CE class as a company in the fall.
It’s an A2L and they had to come up with the L designation pretty recently because of how lightly flammable these gases are. Yet the entire industry is freaking out about it.
Well new and slightly flammable means selling more tools and other stuff so gotta get that money
I work for an HVAC manufacturer. We make zero tools for the trade. There’s no financial incentive for us to change refrigerants.
I see, if it wasn’t a requirement no one would I was thinking of the tool manufacturers and supply houses
Not too many tools are going to change. Maybe a set of gauges. Supply houses are actually impacted because they now have to inventory 1-2 different types of refrigerant as well as maintain stock of 410a. They have product inventory they desperately want to get rid of as well. I promise refrigerant change is not a money making scheme devised by big HVAC.
No I understand it’s a regulatory thing and not a money making scheme, they’re (supply houses) selling us (hvac companies) on new guages, new vacuum pumps with a different style motor, press tools and heads for linesets because they’re saying we can’t braze anymore, little adapter for the refrigerant bottles, and I think that’s most of it. Supply houses are pushing those things pretty hard
I don't understand your comment. Really I don't understand if you're being sarcastic or not. Propane is a great refrigerant, people are afraid of it because it is flammable. Specifically it was considered a replacement for R-12 in cars but was ultimately abandoned in favor of R-134a. Why is having a flammable substance in vehicles so dangerous given that gasoline is highly flammable? This same argument goes for the use of hydrogen as a fuel source in combustion engines.
It's not used in vehicles because the refrigerant lines can get ruptured. Vehicle refrigerant lines are made of fairly soft tubing. Cars have blown up in what would otherwise be uneventful front end collisions because somebody cheaped out and put propane in their AC system.
Gasoline is run through soft rubber hoses and pumped at high pressure from the rear of the car. The argument seems silly to me that there is a refrigerant that is readily available, and relatively safe, while definitely much safer to the environment yet people are afraid to use it because it's dangerous. While we have gasoline which is highly flammable and difficult to extinguish once ignited already in the vehicle.
Upper and lower flammability limits for propane and gasoline are similar but gasoline has a much lower vapor pressure it is far less likely to be a vapor at atmospheric pressure than propane which is a gas at atmospheric pressure
You're forgetting how the AC system is set up in a car, and that changes everything. There are AC lines and a condenser on the front of every car, either right in front of or behind the radiator. So the AC system is involved in, and compromised by, almost every vehicle collision. This system also runs into the passenger cabin, so if it catches fire or explodes it's going to directly expose the occupants. The fuel system is not usually affected in this way, so it has a much lower chance of causing a problem, and it's completely separated from the passenger compartment of the vehicle.
>Why is having a flammable substance in vehicles so dangerous given that gasoline is highly flammable? For a lot of reasons. Propane at ambient temperatures is a gas and gasoline/petrol or diesel are liquids. The vapors are significantly more flammable than the liquids. The flashpoint of propane is lower than the lowest temperature recorded on earth in human history. A typical fuel system in an ICE has the reservoir(gas tank) on the opposite end of the vehicle from the engine where combustion occurs with check valves separating the supply and functional end. A simple HVAC system doesn't have a reservoir. All of the product is in circulation and the system relies on compression to function. Propane remains a vapor throughout the entire process involved in cooling, meaning that it is a flammable vapor under compression throughout the whole system, which is closed and has no vent. Gasoline and diesel at 1 atmosphere are flammable, not explosive. The explosion that occurs in the cylinder of an engine is due to the fact that the vaporized gasoline is compressed and ignited with a spark. This exothermic/exobaric reaction is designed and contained within a heavy metal cylinder with a designated exhaust port. Simply put: Gas is flammable. If your engine catches fire then the fuel inside it will explode, but the fuel in your engine is mostly inside a vessel designed to contain said explosion. If the fire reaches the gas tank it will explode, though the tank is designed to not contain much pressure leading to a low order detonation. If there is ignition inside an HVAC system using propane as coolant, the system is already pressurized. If a flame manages to flash into the system it will propagate rapidly and explode. In the event of a collision a leak of the HVAC system in a car is almost guaranteed which could cause the above situation. Propane is an excellent coolant for systems where exposure to a flame/heat source during a leak isn't a likely concern. Which is the exact opposite condition of what occurs underneath the hood of a car. Source: Former explosive technician and HVAC supplier.
I remember there was a plane crash bc the fuel vaporized and became way more flammable (there was an unknown design flaw) and a small spark caused it to explode in flight
TWA Flight 800. I think the theory is that the climate control (ironic given this post) was located directly under or beside the center wing tank and, since the flight was delayed, was running more than usual. That combined with the weather, heated up the fuel and allowed a spark to easily ignite the vapors within the tank. The crash led to the widespread use of inerting agents like nitrogen in fuel tanks.
empty fuel tank with just vapors in it.
Thank you for your well thought out response. Most people just downvote and move on. The argument I have is that gasoline is a lot more dangerous than people give it credit for due to complacency. I think with the proper refrigerant lines a safety margin could be built in. But I don't see it eve happening.
>I think with the proper refrigerant lines a safety margin could be built in. Not in a machine that regularly travels 70mph where a collision with other machines of equivalent masses is a concern you have to factor in.
I knew I had read about propane being used already in automotive applications. R290 is refrigerant grade propane and is being used in automotive applications. There are a lot of sources stating that it will be wider spread in the future as well.
> If a flame manages to flash into the system it will propagate rapidly and explode. There's no oxygen inside the system. If the engine catches fire, the AC system will get hot, exceed its pressure limit, and burst- or blow out a safety valve. In the case of a safety valve, that's a powerful additional flame, in a location chosen for safety, in a car that was already burning. If the system bursts, that's much worse, but it should be unilikely.
Yes in a closed system it won't ignite due to vacuum. But in a crash where everything starts to bend and break, the lines are going to be compromised before any type of safety valve can evacuate the refrigerant. Two breaks with air entering the suction line and a flame entering elsewhere, especially the discharge line, then you've got a bad recipe. I'm sure people smarter than me could design fail-safes to mitigate the danger, but that would be a more complicated(expensive) change and at the end of the day you're still introducing a hazard by putting another flammable material into the equation.
the propane vapor concentration needs to be between about 2 and 10 percent for propane to ignite in normal air, which is roughly 20 percent oxygen. Outside these limits there isn't enough propane or there isn't enough oxygen and there is no ignition at atmospheric pressure.
I used propane in my old ass truck because I couldn't find R12, and I didn't want to shell out the money to replace the system to R-134a. It worked great.
This entire thing is proof the word "natural" does not necessarily mean safer or better
Just wait till you learn about "essential" oils
Cyanide is in Appleseeds! Can't be bad for you, right?
The essential is related to "essence" not "necessary".
There's nothing natural about the ammonia used for refrigeration It's manufactured in a highly CO2 producing process
Not to mention that hog farms create an enormous amount of extremely natural ammonia that is a huge environmental problem for groundwater and surrounding fields.
Just mix it with a equal amount of bleach. Should be fine. /s (Do NOT EVER do this)
Yes but if there’s a leak it won’t destroy the environment. Synthetic refrigerants are typically way worse for the ozone and sometimes for greenhouse gases than natural refrigerants.
If there’s a leak it will just kill you, but not destroy the environment.
Yes but like methane and other gases, given wet conditons during a spill ammonia can dissolve into groundwater and cause massive environmental issues.
This isn’t the case anymore. There are plenty of fluorinated (gasp!) refrigerants that are non-ozone depleting and non-toxic. They are not cheap.
Ammonia is a toxic gas If it leaks, people can die Manufacturing it, as I said, is _extremely_ destructive to the atmosphere
Are you volunteering to have propane running through your walls in a thin copper line?
Idk bro they already run methane through my walls
Yeah, but methane is lighter than air, while propane is heavier. The general effect here is that a slow methane leak will simply escape the structure, while a slow propane leak might find a deep well somewhere (e.g. basement) to collect until it becomes a serious problem. This is also why venting a house that has had a propane leak is typically such a PITA compared to one that had a natural gas leak. Propane tends to form hidden pockets that resist simple ventilation techniques (i.e. shut off the power and open all the windows/doors).
good point
It’s a fair point, but iron pipe is much safer from accidental damage than copper line sets.
I see new fridges with cyclopentane in them. That is flammable. Doesn't seem safe to me.
A lot of fridges use flammable refrigerants now, but the quantity is relatively small (less than a pound of gas). But yeah, could do serious damage in a small area.
Mine uses 65 grams of isobutane, not enough to attain an explosive concentration in a kitchen. Inside the fridge itself is another matter, you pretty much just have to trust them that they use the right switches and connectors that don't spark. It would have been better if they could cut the fill to 30 grams or less then it wouldn't even be able to exceed LEL inside the fridge.
My new fridge uses isobutane (r600a). 65 grams of it (2 ounces). It’s really a non issue, it isn’t enough isobutane to create an explosive mix in a kitchen. LEL is about 1.8% by volume which works out to those 65 grams being non explosive if mixed with over 1.4 cubic meters of air Inside the fridge itself, an explosive concentration is possible but there are no spark sources (the switches are all encapsulated when using flammable refrigerants). edit: and as far as the inside of the fridge goes, it is primarily a matter of good ol "you got to use the right components" engineering. Connectors and switches that don't spark. Obviously you can't have lightbulbs in sockets or regular switches or otherwise build it as if it was R134A
Fridges are at lease on the inside of the wall in a room that probably has a smoke detector. In the walls lets the problem (remote as it is) get big before you may notice.
I see people literally filling up a tank inside their car with highly flammable liquids before heading out on the road at 80mph, just a few feet away from other people doing exactly the same thing, but going the other way. Nutcases the lot of them.
It’s almost like we’ve spent 120 years improving that technology to the point it’s extremely safe. Also, liquid gasoline doesn’t combust easily.
I'd happily use a monobloc system that all lived outside with a few pounds of propane.
Which is the only way it could possibly be done safely. Retrofitting existing homes will not be affordable.
You just use chilled water as an intermediary, which makes it a fairly easy retrofit. Still less cost effective than swapping to r454.
That starts on January first. Both new refrigerants that will be used are part propane and identified as mildly flammable. Commercial appliances now use refined pure propane and require us to use special recovery machines when removing refrigerant for repairs. Evaporator coils will also require a built in leak detector. But that so far hasn’t been sorted out by our manufacturer which is Rheem.
Propane is not “mildly flammable”. It’s an A3. The new refrigerants are A2Ls and they are very difficult to make burn. Neither R-32 nor R-454B contain propane - they are synthetic chemical compositions.
NH3 is highly toxic..... how are they going to fix this problem?
Which is precisely why it is isn’t used much anymore outside of specialized use cases like ice rinks. Just because it’s naturally occurring and not a greenhouse doesn’t make it safe.
They still use ammonia for cold storage, food processing and freezing. Some places use liquid nitrogen to quick freeze food, but that is extremely expensive and not as efficient as using ammonia freezers. There are berry processing plants that use ammonia freezing tunnels to instant quick freeze their berries and keep them in cold storage. Ammonia is dangerous, that's why those places have to have people that are certified and trained to handle ammonia. There's a place that uses 9000 lbs of ammonia for their processing plant. They have safety measures in case of a leak. Like the vacuum the ammonia that's in the system and transfer it to a dilution tank to keep it from spreading.
Same way they handle natural gas, make it smell horrible so it's easy to detect leaks. Unlike natural gas, you don't need to add an odorant. It smells awful on its own. You can be exposed to an ammonia leak for half an hour without lasting health effects though. Not like you would want to, again, it smells awful.
When you walk into an area with an ammonia leak, it feels like you can't breathe. It feels like the air is being sucked out of your lungs. You panic and scramble to get back to good old air. Ammonia combines with moisture in the lungs and forms ammonium hydroxide, which is the ammonia used for cleaning. It would be a horrible way to die. When it happened to me, I was outside, it was a very small leak, so I was able to get away. 0/10. 0 stars. I do not recommend .
You're in an area with an ammonia leak every time you use ammonium hydroxide to clean. It is not stable at room temperature. What you're describing probably wasn't a small leak, maybe in the [300 ppm range?](https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://teamster.org/sites/default/files/ammonia.pdf&ved=2ahUKEwiCitOb7L-GAxUMOUQIHbRhHekQFnoECBUQAQ&usg=AOvVaw1_PPDPW2QNF3JlQZpuR--J)
How are you going to smell anything in your sleep?
Just don't sleep in your kitchen
Ah yes because ammonia is really nice and polite and stays in the room it leaked from Definitely doesn't spread
I'm skeptical the amount you would have in a refrigerator would be enough to make a kitchen unsafe if it all leaked out, let alone a whole house. Gasses dilute as they spread.
I work in a cold plant and they use ammonia here for cooling. It's great except when it leaks cause its pretty poisonous and we have to have power engineers on hand at all times to deal with it in case an oopsy happens. I don't know if freon is poisonous but if it is I assume it's not as bad.
Common freon 12/22/134/404 etc isn't poisonous but it's way heavier than air and will asphyxiate you in an enclosed unventiated space. And if it hits an open flame all bets are off, lots of horrible shit coming from that reaction.
I heard a story where a theater was using an old 1950s era refrigerator as a stage prop. One day the refrigerator leaked out all of its ammonia and the whole building had to be evacuated. It smelled like cat pee.
I do NOT want an ammonia powered fridge anywhere close to where I live.
If you live near any large facility that handles food, I've got bad news for you. A lot of supermarkets use ammonia systems to keep their meat/dairy cold as well.
The problem is that natural refrigerants are by and large toxic or explosive. So, leaks that inevitably form have the potential to severely injure or kill homeowners. There may be ways to help minimize this risk but they all involved increased cost and complexity
Yeah we tried ammonia once already. People died. Lots of people.
and we can convert 100% of our balloons to hydrogen
> Natural refrigerants are preferred actually in new equipment to their synthetic counterparts for their presumption of higher degrees of sustainability. Lmao citation needed and the sentence sounds like a valley girl with that “actually”
I wonder if I can find a youtube video of "Explaining the Ending of Mosquito Coast"
It always bothered me that the amazing contraption that Harrison Ford invented in that movie had already been a viable invention for a hundred years. Ammonia absorption cycle.
Read up on methyl chloride and ammonia and the deaths resulting from early generation refrigerants. There's a reason we went to CFCs in the first place and HFCs now
The amount of uninformed takes on this about ammonia and its uses ammonia is an enormous part of industrial refrigeration. Ammonia is better used for super low applications like cooling syltherm to -30 for reactor cooling in large pharma plants or large freezers for food production it’s used absolutely everywhere. Propane and butane are more used in really small applications like your fridge at home.
Ammonia is fucking dangerous and explosive to boot. Terrible idea for most systems to be ammonia, unfortunately
what that smell like
death
Smelling salts capsules
CO2 is probably safest alternative. Idk if it is viable for small systems tho.
If if if.. if my mom had balls she’d be my dad. I work in the trade and it’s not that simple, cost effective or efficient
*Annndddd*.... ammonia is highly toxic.
You should apply at The Onion
Ah yes ammonia, It's really cool until a fridge starts leaking and kills an entire apartment block....... What a stupid argument, you can also use petrol as a refrigerant, until it sends the fridge through the fucking roof
You would’ve been better off saying CO2 instead of ammonia. In Europe they’re starting to use a lot of CO2 systems for supermarkets and “small” refrigeration systems
Can’t heat pumps solve this issue with refrigerants?
You mean geothermal heat pumps?
You do know that the rationale for freon-type refrigeration gases is that ammonia is a toxic bomb waiting to go off. Suggest you look up various industrial accidents where whole neighborhoods get gassed
Ammonia is dangerous as shit, it was one of the *very first* refrigerants but was largely abandoned.
Won't somebody think of DuPont?? How will they maintain their monopoly?
Breaking news: DuPont warns ammonia refrigerators on boats could leak and baby sea turtles could DIE! The Forest and Wildlife Service will not allow any ammonia refrigerators to be used until their 5-year investigation is complete and the FAA completes their incident investigation, which can only begin after the other one is complete.
CFCs were removed from Freon 20+ years ago. There zero need to do this.
r134a refrigerant creates a forever chemical when it mixes with water vapor in the atmosphere.