OWB heated walkway

[HD-tech-NH]

Thinking of doing a walkway this summer. Would be concrete. I am thinking of using the second zone on my CB to heat it. Is any one here running a setup like this? I figured PEX. What size and how far apart should the coils be? How long of a run? What kind of anti freeze? Should I use foam insulation under the concrete? Any ideas?

 

[John D]

I hope the walkway isnt that long...I would insulate and vapor barrier under it.Everyone here uses 1/2" pex.The idea is cool,just not sure how much harder the owb will have to work,and how much you'll need to feed it...you will likely need glycol in the system unless you use it all winter,Id rather use it as needed only....that alone can cost close to a grand.

 

[ericjeeper]

as others mentioned,vapor barrier and I personally would use 2 inch pink board under it.
Screw the insultarp and bubblecrap. you can use a heat exchanger and keep the sidewalk side glycol and the rest of the system H20.Use a separate pump. Piece of cake, visit our friends over at heating help.com go to "the wall"

 

[woodman6666]

I agree with ericjeeper keep it separate with water to water exchanger and only run when necessary I looked into doing this to my concrete pad in front of my new house but decided it would not be feasible but that was 100 yards I think for something small it might be a good idea

 

[mtfallsmikey]

Not to be a shill again, but....


www.heatinghelp.com

Lots of radiant contractors over there who have been there/done that...

 

[coyotencuttin]

insulate under your sidewalk with 2" pink/blue insulation, 1/2" pex 12 inch on center,300 foot run maximum per loop, better start cutting wood for this winter now cause your gonna need it. if you want to throw your snow shovel away put your pex in at 6 inch center. snow melt takes alot of btu and is slow. have a heating contractor familiar with snow melt do a load calculation for your sidewalk to see how many btu you'll need and size the boiler according. let us know, harold opcorn:

 

[HD-tech-NH]

what about using brick?

 

[coyotencuttin]

Do you mean paver type brick? Gonna need to put the pex in your sand layer. But the problem is you are going to need more heat to also heat the sand. Probably need to run the pex 6inch apart to put more heat into the walkway. Harold

 

[RVALUE]

I have only been around one driveway heater. It was electric, and I would say very inefficient. The HO's thought it was great because, "when it snows, it comes on and melts the snow." BS, it was simply on a thermostat. It was on whenver the air temp was under 35. It did melt the snow, but at what cost.

So my advice is to manually control it, when you need it. And a decent fire would melt alot of snow. Slowly.

 

[Baldman]

As long as you have the driveway on a different 'zone' and turn it on only when needed would be the best way to go. Assuming you have the insulation and glycol in that zone already.

 

[HD-tech-NH]

Do you mean paver type brick? Gonna need to put the pex in your sand layer. But the problem is you are going to need more heat to also heat the sand. Probably need to run the pex 6inch apart to put more heat into the walkway. Harold

My problem with that is when the snow melts the water will drain below the brick and heat soak the pex. The concrete would probably be best. Maybe I could tint the crete brick red and use a paver template instead of the cobble stone template. I must say we are talking about a walkway here not a driveway. maybe 60 - 70 feet long. That would be heated by my existing CB 5036. 6 in on center 1/2" pex with 2" foam board below the concrete. Probably a good 6" of gravel below that. Or sand?

 

[HD-tech-NH]

Not to be a shill again, but....


www.heatinghelp.com

Lots of radiant contractors over there who have been there/done that...

great link thanks!

 

[ericjeeper]

never use sand as a heat conductor, it is piss poor to say the least,. Best example I can give you,ever been to the beach and the sand is so blasted hot you can not stand on it.. yet if you wiggle your feet into the sand just an inch or so the sand is much cooler?
I state my case.
Best thing you can use is crushed limestone.
When I built my house back in 2004 I installed 3500 feet of radiant tubing in the house slab. But none in my slab in front of the garage,, Big big mistake. My slab is on the north side of the house.25x48 and will hold snow and ice til spring., One of these days I am going to bust it out and re-pour it with a glycol loop. At the time I built the house I was using a fuel oil fired water heater. I Built a wood fired boiler after the towel heads got so proud of their crude,
I will be using 2 inch pink board with 1/2 inch pex 12 inches on center. I do know how hard it will slam a boiler too. My garage is 25x40 and When it calls for heat about once a day.. It will suck the life right out of my boiler, so I can imagine how bad a slab outside will be.. But oh well it is only firewood..God grows more every day.