Freezer as Ice thermal storage air conditioning

[Vigo]

Maybe I am getting too complex. Just super freeze a 100s of plastic water bottles and blow air through box of them.

I think this should be basically anyone’s first attempt, to minimize any disappointments that may arise.

My first instinct would be to choose water containers that stack in such a way that guarantee air passages (such as water bottles), leave them IN the freezer, and just blow air through the whole thing. Honestly, if there were room in the freezer for a fan id just leave that in there too and if there’s a light in the freezer i would just wire an appropriate fan to the light socket so it ran when the door was open. Put freezer on a cheap timer switch so its off when solar goes away, open the door to it right as you go to bed, and just see how it goes. The total prep time for this is in the single digit hours even if you have to go buy every single piece of it in person at stores. If you already have all the pieces it might be one hour.

 

[32 volt boater]

The phase change (ice to liquid) is where the bulk of the energy extraction occurs. Lowering that melting point really provides no benefit in this instance.

True on the energy part but I think it would help tremendously when its time to make cold air if you are using colder ice.

-6°F air output vs 32°F / -21°C vs 0°C

Need less volume of air I would imagine.

 

[32 volt boater]

I think this should be basically anyone’s first attempt, to minimize any disappointments that may arise.

My first instinct would be to choose water containers that stack in such a way that guarantee air passages (such as water bottles), leave them IN the freezer, and just blow air through the whole thing. Honestly, if there were room in the freezer for a fan id just leave that in there too and if there’s a light in the freezer i would just wire an appropriate fan to the light socket so it ran when the door was open. Put freezer on a cheap timer switch so its off when solar goes away, open the door to it right as you go to bed, and just see how it goes. The total prep time for this is in the single digit hours even if you have to go buy every single piece of it in person at stores. If you already have all the pieces it might be one hour.

Was thinking about this and if plastic bottles work aluminum would probably work better.

Aluminum has a thermal conductivity of 137 [BTU/(hr·ft⋅°F)] or 237 [W/m-K] at room temperature.

What ever that means

V Plastics are poor heat conductors, because they have virtually no free electrons available for conduction mechanisms like metals.

Polyethylene terephthalate (PET or PETE) plastic – the source material of water bottles, For post-consumer PET, the thermal conductivity is 0.19 W/m °C and the literature value for virgin PET is 0.0375 W/m °C at 25 °C

And I have a math headache now ! Feet to meters 137 and 0.19 and 0.0375 ! Aluminum is just better.

I searched buy Al bottles and you can buy in bulk. Don't think a thicker Al bottle would split from freezing ice like a thin beer type as long as not totally full of course.

 

[bgflyguy]

I played around with one of those coolers filled with ice and holes to run air through. Even full of ice with a couple of freezer packs, it only lasted like 30min in the heat. I would expect you would need hundreds of pounds of ice to do anything substantial.

 

[Vigo]

As i said in some other thread, the actual need for cooling drops precipitously the further you get from sunset, AND it might drop significantly the moment you fall asleep. In my mind most of what 'ice block cooling' needs to accomplish is to allow you to GET to sleep, and once you're asleep, the actual cooling needed to keep the space at a temp 'below that which will wake you up', hopefully tapers nearly to zero by or before the time your ice ceases to do anything. I guess it depends how hot of a place you are in, and how cool you need to be to stay asleep..

This is just a theory.

 

[cinergi]

Reminds me of this: https://www.icybreeze.com/

 

[Vigo]

The video on their product page gives some pretty helpful context about what's possible. That size cooler, how much ice you put in it, how long is it going to cool, even the power requirement of their fan+pump (4-6.5ah batteries of likely ~18v = 70-120wh for fan AND pump).

It really seems like the main struggle of something like this is just properly calibrating your expectations.