[energy tips]
FREEZER FABLE
Frozen water bottles not
likely to save energy
W
Will packing an empty freezer space with filled water bottles reduce energy consumption? Although this is an energy efficiency tip that’s commonly repeated online, it really doesn’t hold water. The thinking behind this idea seems to be that by decreasing the amount of airspace in the freezer, you’ll lose less cold air every time it’s opened, and you’ll save energy as a result. Consider the energy required to cool a single bottle containing 16 fluid ounces of water. To freeze it, you would need to remove about 50 kilojoules (kJ) of energy to cool the water from room temperature down to 32 degrees, and an additional 158 kJ of energy to change its state from a liquid to a solid. In total, around 208 kJ of energy must be removed from the water to freeze it solid from room temperature. In contrast, cooling 16 fluid ounces of air from room temperature to 32 degrees would only require you to remove 0.015 kJ of energy. This is about 14,000 times less energy than is required to freeze the same volume of water to a solid state. An important caveat here is that we’re assuming that room temperature water is being used. If, for example, you were to put some water bottles outside in winter, let them freeze wand then put them into the freezer, they would help to offset the cooling load and thereby save energy. — Cooperative Research Network
“How did it get so late so soon? It’s night before it’s afternoon. December is here before its June. My goodness how the time has flewn. How did it get so late so soon?”
For more information on the frozen bottle myth, visit coloradocountrylife.coop. Click on Energy Tips.
— Theodor Geisel ColoradoCountryLife.coop June 2013 25