Water Bottles in the Freezer / Fridge


This is a neat idea to save energy on your fridge and freezer. It was suggested in the Riot 4 Austerity discussion group. I’m happy to have found it because our inherited fridge-freezer is an old one and we could definitely use some KWH savings there.

It makes sense that it takes a lot of energy to cool an empty fridge or freezer. Not that it takes longer to cool air than, say, a gallon of milk, quite the contrary. The problem is when you open the fridge or freezer door. All that cooled air simply tumbles out (especially if you have an upright – cold air is denser and heavier than warm air). But the cold in the gallon of milk largely stays put. All the things in your fridge and freezer are “cold-sinks”.

So the solution is to fill you fridge or freezer with these sinks: bottles of water, for instance. There will be be an initial extra investment cooling them, but after they’ve reached the desired temperature, each time the machine is opened, (1) more coldness will be retained and (2) there will be less air to cool and re-cool.

But the idea goes further: if you live in freezing temperatures (as we do), why not fill up some bottles of water and put them outside to freeze, then put them in the fridge and freezer? That eliminates the initial extra investment, and the frozen bottles in the fridge will do some extra cooling, for free.

Just happy to have found another silver lining to our deep-freeze!

{UPDATE} Just my “luck”! Just as I put the bottles outside for freezing, the temperatures shot up!

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