Application Snowmelt/in-floor same unit

hot_rod

is plenty to melt snow. Do a heatload for the building, and also a load calc for the snowmelt. You can adjust flows, tube spacing, loop length, delta T, etc on the snowmelt to make it all happen with one temperature.

Figure at least 125 btu/ square foot for the melt to get any performance. So you are looking at around 180,000 input boiler to carry that load.

Most or the radiant manufacturers have design software that does building and snowmelt calcs. it's much easier to do it on the computer than on the job.

I'd wonder how often you could melt that there would be no heat or DHW load? Pretty hard to make one, sized to the heat load, boiler do both.

If the money is being spent to install snowmelt, you might consider a dedicated boiler. Think inexpensive copper tube for that application if it is infrequently used. Nothing worse than an under performing, multi thousand dollar snowmelt system :) Melting snow is a gas guzzling job redgardless of the equipment selected. Heating the great outdoors, really.



hr

Chap

Snowmelt/in-floor application

I have a potential project where the homeowner is thinking about 5000sq ft of in-floor radiant heat, with an additional 1300sq ft of snowmelt. The snowmelt is second priority and will be used to melt a drive and walk shaded by the house. Looking for some advice as to how best do this. Was hoping to use the same boiler, possibly Prestige or Knight, use the outdoor reset curve for the heating then set up the snowmelt as a heating zone with a dedicated circulator, plate exchanger etc. Maybe oversize the boiler a bit for the heating load but not to account for both. This area doesnt see alot of snow, just occasionaly. Will it work with running in-floor temps for snowmelt, guestimate 120 degree max? 24hr timer a good idea? Am I asking for problems?

lee_7

Why not make snow melt loop a "hot water priority? Hook up call for s/m loop to domestic hw override on ODR, that way you can have the required temps to snowmelt, no matter the temp outside?

Chap

DHW Priority

I will also be using this boiler for DHW production.

Steven Eayrs

Install good S/M controls

Don't go cheap on the controls. At about a 180mbtu load (as already stated), it won't take many cycles of snow melting, in weather that doesn't need it, to pay for the price difference. Just a switch or timer, and forgetting to turn it off, and its simply a big waste of energy.
Of if not controled good enough and its not on......someone slips on the ice. Won't hear any good words about the system from your customer then!

Lots of good controls out there. All snow melt we do we use tekmar controls, including a slab temp sensor and moisture sensor, as well as outdoor air sensor. Well worth the investment.
One good reason for the moisture sensor......It doesn't snow much at 20 below, in our area, so why have the system run just because cold outside? If moisture falls on the sensor, and its below the temps youset it at for coming on, it only runs then.
Can also set it in idle modes. If using a plate heate exchanger as well as injection pump pulling off it, you can run 40 deg out to the slab all day long if you want, and if thats all it needs to melt ice. If the wind picks up and it needs more, it simply adjsut on its own.

Wouldn't dream of wasting the fuel on a snow melt without the good controls. Easily pay for themselves in a couple years.

Chap

Thx

Thanks for the help