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Before the invention and commercialization of refrigeration, many homes had an ice box, designed to store a large block of ice to keep perishables cold (from the National Museum of American History):

Ice box

Ice was harvested in the winter from frozen lakes, and stored in huge piles covered in hay or other insulation.

While today a refrigerator is much more convenient from spring to fall, it occurs to me that with all the snow lying on the ground around my house (up to a meter deep in spots -- I'm in Wisconsin, USA), I could apply the same principle in winter.

Is there any sort of strategy to use snow to make my refrigerator more efficient in the winter? Like an ice box, perhaps there's a simple way to store the snow/ice, while collecting the melt water to keep it from making a mess. Has anyone implemented something like this?

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  • I think most people find it more convenient to plug in an electric refrigerator than put in ice and take out water every couple days. Although when camping in the mountains , I used compressed snow ( 50 % ice) in a cooler chest.. Feb 16 at 15:52
  • You really need an "ice box", they were pretty clever ; various compartments and drinking water tank. ( I remember a neighbors from a very long time ago). A refrigerator would not be very effective substitute. Feb 16 at 21:19
  • @blacksmith37 I was thinking of something that would fit inside my fridge in the winter -- a compartment on top for snow, and a reservoir underneath to collect the water. Every few day you drain the water and add more snow. Obviously this would take up space, but could it be worthwhile?
    – LShaver
    Mar 3 at 16:20
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Imma use metric here. If you explore this field any more, you'll be swimming in metric, so might as well jump in now. 0C is freezing, 100C is boiling point (212F), and body temperature is 37C.

Use a fluid-sourced refrigerator.

Your refrigerator is a heat pump. It is using a fluid (a type of freon) to pump heat from inside the fridge to outside the fridge. It has an evaporator (cold thing)* inside the fridge and a condenser (the hot thing) outside the fridge, typically in the back of the fridge where there is poor air circulation. As a result it's pumping heat from a space that is -10C and 5C, to a space that is 50C.

Here's the thing about that. Pumping "uphill" (from a hot space to a cold space) is inefficient! That's one of the reason ground-sourced heat pumps work better - they interact with 50F ground water at all times, instead of trying to get heat out of -15C winter days and dump heat into 30C summer days. Air-interchanged heat pumps are always pumping uphill, and your fridge is no exception.

Pumping uphill vs downhill has a huge impact on heat pump efficiency.

By contrast, my parents' apartment has a heat pump that runs on facility service water. That is delivered at 45C in the winter, and their thermostat is set to 22C. The heat pump is "pumping downhill", so it runs very efficiently.

The fluid is fed from an ice house

So let's flip the script. Suppose you have an "ice house" on your property... an enormous, hyper-insulated shed positioned so you just plow all your driveway snow into it. At the bottom is a swimming-pool-like structure that is watertight (can't have our 0C water leaking off!) At the bottom of this pool is the refrigerator's condenser.

Now, the condenser is always sitting in water (from snow melt) that is 0C because of all the snow on top of it. It is still a freon refrigerator, but it's vastly more efficient because it's "pumping downhill (or almost so). Far less energy spent.


Of course, the real fun with this is to do it on a larger scale with air conditioning. We're talking a pretty big ice-house though. At that point, you'd probably want to switch to a facility service water" scenario where you have a glycol loop taking chilled water to your freon pumps.

By the way, all the products I named are commercially available. The water-sourced refrigerators are marine units. I mentioned my parents' service-water-sourced heat pump.

Unfortunately you can't do the same thing in summer. You can store ice as cold as you please, and the enthalpy of fusion (latent heat of freezing) is effectively like storing water that is 80C cooler than it is - a very nice boost. It's impossible to do the same thing with storing steam - it's too big and requires a pressure vessel.



* To recap the refrigeration cycle:

  • A low-pressure-gas fluid is compressed into high-pressure gas, which is very hot.
  • It cools in a condenser coil. At that high pressure, the gas wants to be liquid, so aside from simple temperature, it also gives up its latent heat of vaporization or "enthalpy", which only makes the cycle work even better. This happens in the hot coils on the back side of your refrigerator.
  • The warm, high pressure liquid moves back inside your refrigerator.
  • It goes through a pressure regulating valve which greatly reduces its pressure. Just as compressing made it hot, decompressing it made it cold. (Getting the picture?)
  • At this pressure, it wants to be gas again. However, to turn into gas, it needs its enthalpy back! So it steals energy from the environment (the inside of your fridge). The evaporator coil inside your refrigerator is designed to make that easy for it.

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