electric vs radiant sno melt

Mark Eatherton

it's 90 cents per therm for nat. gas, or 2.92 per therm for electric.

ME

[Deleted User]

electric snomelt

Does any one have a chart on the cost of electric vs hydronic snomelt? We have a 2000 sqft drive way we want to install hydronic snomelt in but the home owner is leaning towards electric.
Any help trying to lead him in the right direction would be great!

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

scrook_3

So...

a 2000 sq ft snowmelt area at say 100 BTU/hr per sq ft will require 200,000 BTU/hr or 58.6 kW. Assuming 240V electric service that's 244 Amps! If they needed a bit more, or the area is a bit larger than it's even worse

Given that the circuit(s) are not allowed to exceed 80% of the circuit breaker rating per NEC (or breaker/circuit greater than 125% of max load) you'd need at least a 305Amp survace -- so assume an ADDITIONAL 400 Amp service, over and above any existing service just to support the snowmelt! This would be good for up to to about 2600 SF at 100/SF or 2000 SF at 133 BTU/hr per SF!

Too you'd need a lot of LARGE gauge wire (assume one runs five (or perhaps six) 60 Amp/240V circuits (each at 48 amps or a little less) that's 6 pairs of 6 AWG copper from panel to heated area; with ten to twelve 30A/240V circuits instead it's still basically the same amount of copper, no free lunches! Also heavy duty contactors will be required to switch this.

A boiler and PEX starts looking better and better, even before the first dollar (or $3 if electric) is spent for energy.

Mark Eatherton

And then there's the demand charge per KW of demand...

If electricity is your ONLY option, I'd recommend going with hydronic tubing, powered by an electric boiler, because once the electric circuits in the concrete fail (and they are prone to doing just that), you are S.O.L. Even if you COULD locate the exact location of the circuit break, doing a long term reliable repair becomes an issue. At least with hydronics, you can find the leak and repair it.

And the demand ratchet charge, will bust your budget in a hurry...

Here in CO, whatever your peak demand is for a 20 minute window, becomes the base demand charge you pay for for the next six months, or until a higher demand is set, which ever comes first.

ME