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Comment by computator | Hacker News Reader

Considering that this idea has been around forever and that it isn’t nearly as expensive[1] as you might initially assume, I wonder why it isn’t a standard feature of most homes in cold climates.

[1] “A snow melting system that heats the tire tracks only for a 10’x20’ driveway, is $2,346.” Paraphrased from https://www.floorheatingsystemsinc.com/snow-melting-system-c...

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In climates where you get heavy snowfall (e.g. the northeast) most such systems can’t keep up, and you end up with a foot of snow sitting on a crust of ice, which is harder to clean up. The system will catch up eventually, melting from the bottom up, but it’s inefficient and very slow (and you get ice dams if there are any cold spots).

Sufficiently powerful systems work well, but are $$$$ and relatively energy-intensive, from my understanding. Paying the neighborhood plow guy is easy.

Plus at -40C, how do you keep up? You are battling everything being cold, including the ground under you.

People in this thread are saying "just heat always..." wha?! Heating an insulated home is crazy expensive at -40C, and you want to heat a driveway from -40C to 10C, and melt all the snow?!

(Heating to 0C is not sufficient to melt and let stuff run off, it will freeze again too fast.)

And beyond that, now the end of your driveway is solid ice. Or it will be, as the drain freezes.

A gas snow blower is better for the environment, 100x better, than that.

The good news is that at –40 it barely snows and the stuff that does fall is super light so you can just let the wind blow it away and clear the drifts, but yeah, exactly this.

I have heating in my driveway, it’s OK if it’s just a little bit of snow, but other than that it’s worse than useless. Most of the winter I keep it off and clear the snow with a good old fashioned flatbed shovel thing. Like this: https://www.obs.no/bygg-og-hage/hage-og-uterom/vinterredskap...

Overcoming the latent heat of fusion (melting frozen water) takes a LOT of energy.

Melting 11kg of ice to 11kg of water at 0°C takes about 1 kWh of energy. That’s 3 or 4 good shovel-fulls of heavy snow. That’s only to get it to 0°C water. Getting it to 10°C to keep it from insta-freezing right next to the snowmelt takes another 1/8 kWh.

Before the melting starts, you’re going to heat an entire sidewalk from negative a few degrees to 10-15°C and all that energy will go un-recovered after the storm.

Thank you for revealing how stupid electrically heated driveways are. If I ever have a driveway in a snowy climate, it's going to be geothermal and channel the water to drain into inclined conduit with turbines to put the melted snow to work offsetting electric bills on cloudy days when the panels aren't producing.

So it sounds like maybe 5kWh would be needed to melt snow/ice on a short run of stairs, but what continuous power level is needed? Maybe 300W of solar power applied over two days or 600W over one day would be enough to clear the stairs? Especially if you painted the stairs black. Maybe the stair heaters could be run sequentially from solar power to clear a stair at a time. A $1000 investment in 600W of solar panels and some black heating pads for the stairs seems like a reasonable cost (for some people or for a business worried about liability) for an often used small stairway to keep it clear for a few decades.

How much does the energy cost? Having this as a standard feature would be a terrible, terrible idea. The disruption to the environment would be immense.

It is fairly standard for homes in Hokkaido and some businesses heat the sidewalks of their storefronts. Manual clearing is also still very prevalent.

Some resident owners will opt to clear snow manually just to save money. I notice in the site you linked they did not mention cost of running it per hour. When snow starts in November and can occur as late as April, cost of daily running does add up.

Such systems are illegal in my state (Wisconsin) except for special circumstances (e.g., hospitals).

Because of energy waste or some other reason?

Looks like the law was passed in 1980 due to the 1970s energy crisis, but it was repealed back in 2008: https://www.twincities.com/2008/01/15/bill-would-allow-for-h...

Reminds me of the misguided pepper spray law that was relaxed a decade ago, but Amazon still won't ship completely legal pepper spray to Wisconsin and a bunch of sites still claim it has draconian regulations.

My understanding is that the primary cost is in the operating electricity costs, which is expensive.

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