What's the coldest freezer available? I looked it up, and the coldest commercial freezer was -86 Degrees, and the only other thing I found were that there was something that could make atoms cold slightly above absolute zero. But I want something colder than -86, more like -120. My main goal is to have a big warehouse sized dome at around -100 degrees (C or F). Is it possible?

A bottle of liquid nitrogen...

Or, get a tank of helium and pressurize it enough to make helium ice (actually don't lol).

It was meant just partially as a joke. The truth is, for such purpose the liquid Nitrogen is used commercially - in many cases it is cheaper (its main production comes as a nearly waste byproduct from distilling an industrial liquid Oxygen and Argon, so it is subsidized by the sale of these gasses) than maintain and run the machinery capable of such cooling...

A bottle of helium or nitrogen won't be enough, because you need a lot to constantly cool a stadium sized area.
I assume the freezers use compressor refrigeration, so is it possible with that?

Don't mind me asking but just WHAT do you want to do with temps that cold?

A bottle of helium or nitrogen won't be enough, because you need a lot to constantly cool a stadium sized area.

Never heard of any stadium (or so) sized area cooled below -40degC or so (ice stadiums alone are usually cooled down to -5 to -10degC, the freezer storage facilities to about -30degC) and these indeed do use rather regular refrigeration machinery.
For lower temperatures I know only about pots or maximum cabinet size storage and most of them are already using the liquid Nitrogen or when approaching 100 Kelvin or below, even Helium or so.

I assume the freezers use compressor refrigeration, so is it possible with that?

Well, for the regular style refrigeration machinery (compressor-condenser-valve-evaporator cycle) the limit is around -50degC (with multistage maybe down to -100degC), while the power consumption grows nearly exponentially when you go lower with temperature. It becomes so high, for temperatures below -50degC (in case of constant use; for an occasional use the refrigeration may be still viable for small spots down to its technical limit, so about -100degC) the liquid Nitrogen becomes cheaper option, although it requires supply of physical goods to keep it cold (a bit more logistic than just drawing some electricity).
When going even further cryogenic, you will start to face two major problems: First the phase change refrigeration won't work anymore, as there are no suitable working media for that. So you have to go to gas only systems. But that means you have to transfer that "coldness" from the machine to the cooled room. With that it becomes way more pract6ical to just use the liquid Nitrogen or Helium (or similar; according to the temperature needed) and just either buy these (the case of Nitrogen, as it is just a bit processed waste product) or build separate facilities to produce these cryogenic substances (a case with Helium with larger institutions using it on many places, so one common facility makes it cheaper because of the economy of scale).

But hey, isnt LN2 itself so cold exactly due to changing pressure in its distillation process ? How is this (by principle) different from any other compression/expansion cooling ?

Don't mind me asking but just WHAT do you want to do with temps that cold?

Tourist attraction, winter testing in the middle of a Florida summer, cool factor, etc.

But hey, isnt LN2 itself so cold exactly due to changing pressure in its distillation process ? How is this (by principle) different from any other compression/expansion cooling ?

The phase change refrigeration need a medium, that is:
- Well below the critical point at the hot side
- Well above freezing on the cold side

The air distilleries use gas only refrigeration systems (close to a Stirling engine, but used in reverse energy transfer mode as a heat pump; the machinery used there is way more complex to just be more efficient, but the concept is not that much different).
That is less efficient than the phase change concept, but it does work to low enough temperatures to allow the air component separation.
The problem of using such concept for general cooling is how to transfer the "cold" from the machinery to the cooled spot efficiently and with the ability to control the temperature (switching it OFF by a thermostat means the machinery will form a heat bridge bringing the heat back into the cooled area, so wasting the energy; with air distillery you operate the machinery at full power till you collect the desired amount of products and then eventually shut it down and don't care if it completely heats up or so).
Of course, you may build such plant just for the cooling purpose. But the point is, even when the air distillery machinery does consumes huge amount of energy, but that get paid from the sale of their main products Oxygen and Argon (and smaller quantities of other noble gasses). But in order to get the few percent of these, they have to cool down the complete air, which is in 80% the Nitrogen. For uses, where the chemical composition is the prime need, there is no competition, so they may charge full distillation cost within those products (Oxygen, Argon,...).  But although the industry needs the whole amount of Argon, huge amount of oxygen, it does not need that much of the Nitrogen as really the Nitrogen (as an inert gas,...). So there is nearly 80% of the cooled air remaining with no use, hence even with all the logistic and transport losses it still became a cheap refrigeration option (even a small bargain is still some extra money for the air distillery), mainly for lower temperatures and constant use (for only occasional use the way more expensive CO2 or higher temperatures even an inefficient machinery remain in use, because the LN can not be stored without gradually loosing it; the CO2 you may store at room temperatures as long as you wish and the machinery consumes of course nothing when not in use).

Quote from: Ash on July 24, 2016, 03:10:14 PM

But hey, isnt LN2 itself so cold exactly due to changing pressure in its distillation process ? How is this (by principle) different from any other compression/expansion cooling ?

The phase change refrigeration need a medium, that is:
- Well below the critical point at the hot side
- Well above freezing on the cold side

The air distilleries use gas only refrigeration systems (close to a Stirling engine, but used in reverse energy transfer mode as a heat pump; the machinery used there is way more complex to just be more efficient, but the concept is not that much different).
That is less efficient than the phase change concept, but it does work to low enough temperatures to allow the air component separation.
The problem of using such concept for general cooling is how to transfer the "cold" from the machinery to the cooled spot efficiently and with the ability to control the temperature (switching it OFF by a thermostat means the machinery will form a heat bridge bringing the heat back into the cooled area, so wasting the energy; with air distillery you operate the machinery at full power till you collect the desired amount of products and then eventually shut it down and don't care if it completely heats up or so).
Of course, you may build such plant just for the cooling purpose. But the point is, even when the air distillery machinery does consumes huge amount of energy, but that get paid from the sale of their main products Oxygen and Argon (and smaller quantities of other noble gasses). But in order to get the few percent of these, they have to cool down the complete air, which is in 80% the Nitrogen. For uses, where the chemical composition is the prime need, there is no competition, so they may charge full distillation cost within those products (Oxygen, Argon,...).  But although the industry needs the whole amount of Argon, huge amount of oxygen, it does not need that much of the Nitrogen as really the Nitrogen (as an inert gas,...). So there is nearly 80% of the cooled air remaining with no use, hence even with all the logistic and transport losses it still became a cheap refrigeration option (even a small bargain is still some extra money for the air distillery), mainly for lower temperatures and constant use (for only occasional use the way more expensive CO2 or higher temperatures even an inefficient machinery remain in use, because the LN can not be stored without gradually loosing it; the CO2 you may store at room temperatures as long as you wish and the machinery consumes of course nothing when not in use).

I would cool this place by using air vents, just like an air conditioner.

Quote from: Zarlog on July 24, 2016, 01:59:27 PM

Don't mind me asking but just WHAT do you want to do with temps that cold?

Tourist attraction, winter testing in the middle of a Florida summer, cool factor, etc.

But hey, for that you won't need anything below -20degC or so, even that will be quite dangerous...
And that is well within the reach of the common refrigeration machinery, you don't need anything special for that.
Just need to install sufficient power and mainly build the room with sufficient insulation. I guess any industrial cooling supplier will carry the required components...

Quote from: wattMaster on July 24, 2016, 03:57:44 PM

Quote from: Zarlog on July 24, 2016, 01:59:27 PM

Don't mind me asking but just WHAT do you want to do with temps that cold?

Tourist attraction, winter testing in the middle of a Florida summer, cool factor, etc.

But hey, for that you won't need anything below -20degC or so, even that will be quite dangerous...
And that is well within the reach of the common refrigeration machinery, you don't need anything special for that.
Just need to install sufficient power and mainly build the room with sufficient insulation. I guess any industrial cooling supplier will carry the required components...

Problem is, -20 is too boring, anybody can find a place that cold.
I have measured a faulty freezer in a grocery store and it was around -60 C.

The problem of using such concept for general cooling is how to transfer the "cold" from the machinery to the cooled spot efficiently and with the ability to control the temperature (switching it OFF by a thermostat means the machinery will form a heat bridge bringing the heat back into the cooled area, so wasting the energy

Solenoid values breaking the gas path when the pump is off ?

Quote from: Medved on July 24, 2016, 04:16:24 PM

The problem of using such concept for general cooling is how to transfer the "cold" from the machinery to the cooled spot efficiently and with the ability to control the temperature (switching it OFF by a thermostat means the machinery will form a heat bridge bringing the heat back into the cooled area, so wasting the energy

Solenoid values breaking the gas path when the pump is off ?

Except I don't think we would need thermostats, it can never be cold enough.