On Snowdrifts

Living in any place frequented by snow occasionally causes some questions to emerge, like “How do I get rid of this?”, “Where is the sidewalk?” and “What does this stuff taste like?”. Or maybe not that last one, unless you’re particularly daring.

Anyways, the first question is what this post is about. Given some amount of snow, how can one get rid of it and clear the driveway? I, and most other people would probably use a shovel, but that strikes me as incredibly boring.

Incidentally, I’ve been practicing my thermochemistry.

Why not melt it? Or no, that would make an interestingly shaped pool of ice and then I’ll have two problems.

I’ll go with vaporization then.

Each cubic metre of snow weighs about 100 kilograms, and the specific heat capacity (energy required per unit mass, in kJ per kg to heat a material by 1 degree celcius) of snow/ice is 2.108 kJ/(kg K).

Once that snow has been brought to 0 degrees celcius, you have to inject quite a bit more heat to make it change states from solid ice to liquid water, that amount being 334 kJ/kg of snow.

Then, you’d have to heat the new puddle of water (Specific heat capacity = 4.18 kJ/(kg K) ) to 100 degrees celcius, and then inject even more energy (actually, an enormous amount, more than the rest combined) to turn the liquid water into gaseous steam. That extra amount is 2,230 kJ/kg.

At the end of all that, you’ll end up with the total amount energy that you need to turn that snow into a cloud of rapidly dissipating steam

That equation written out properly looks like this

I wrote a calculator in Python to do this automatically, just with a few parameters. You’ll find that here: EnthalpyFuser

Happy snow shovelling!

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