How far can I stretch an OWB?

[flashpuppy]

I have been thinking about this for a while. Here are my plans:

heat 2000 sq ft house
provide hot water for the house
heat 2400 sq ft shop
I would like to run wirsbo through all of this

But the biggest thing (I think) is that I hate shoveling. I hate salt. I hate the left over ice that won't ever come up all the way. I want to heat a concrete driveway.

Who else is running something crazy like this? What are all of your thoughts on this?

 

[windthrown]

Driveway and sidewalk heating is a good used for an OWB. However, if you wanna run a hydronic heater through concrete, you have to pour a slab with the PEX in the slab. You can do all that, but you will need a large unit and it will eat a lot of wood. I ran an OWB to the DHW, then the hydronic floor heater, then ran the return line to a water-air Hx in the garage to temper the air out there to a milder 50 degrees. When it got really cold (15 degrees in Oregon), the OWB demanded a LOT of wood. I was thinking of tapping it to heat the hot tub as well, and that unit would have done it. But the hot tub loop has to be isolated when you shock the tub with chlorine, and that was too much of a plumbing PITA and it was too complex to use in actual use (the ex would inadvertantly forget to bypass the heating loop during shock treatment and wreak the flat plate HX).

It can be done though. Firgure 20 cords of seasoned hardwood a year in your area with that size area to heat.

 

[John D]

I have been thinking about this for a while. Here are my plans:

heat 2000 sq ft house
provide hot water for the house
heat 2400 sq ft shop
I would like to run wirsbo through all of this

But the biggest thing (I think) is that I hate shoveling. I hate salt. I hate the left over ice that won't ever come up all the way. I want to heat a concrete driveway.

Who else is running something crazy like this? What are all of your thoughts on this?

I think it is crazy,esp if you dont have the slab already plumbed for heat,or if the slab is bigger than a one car size. Get a 20lb propane cylinder,and a hand held torch, http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_21016_21016. Hit all the icy spots,that sucker puts out a lot of heat.Or just pay a local plowing contractor to shovel your drive.

You will burn so much wood,it just wont be worth it,IMO. As is stands with your home,and shop alone your going to need a boiler with 250+ gallons of water capacity,and 2x a day loading or a 400+gallon water capacity and once a day loading.Add the driveway to it,and I would guess you will need to double the size of the OWB,and double the wood usage.

 

[flashpuppy]

This is all for future plans. I don't have anything built yet, so putting the wirsbo in is not a problem.

As far as plowing it, that's me. I HATE plowing. The last thing I want to do is my own driveway. I used to work at a carwash that had all heated concrete. it was sure nice.

What are everyone elses thoughts?

 

[trialanderror]

i'm heating two houses, two DHW systems, and in the future the floor of a 40x60 with a 20ft cieling building....

doesn't matter how big or how small the boiler. it's gonna eat wood....

my two zones are being done easily with boiler having a 85 gallon waterjacket heating nearly 700gallons of water....just two normal sized wheelbarrows of wood each day, nothing special. it's rated for 485,000 btu/hr, and i'm no where near firing it that hard....draft blower comes on maybe 5-6 times a day for 10 minutes... it's a highly modified steelking, i burn everything, leaves, paper, cardboard, nasty wet fallen down pine, pine needles, anything that'll fit in the door, even a few things the EPA wouldn't be happy about....and yard has cleaned up quite a bit, and it's not even spring yet.....


if you have the wood, and your building form scratch, DO IT!!!! better to have it and not need it....

who says you need to have the ice melted 24/7? and the ground doesn't need to be 180*F, a mild 33-35*F conrete will melt ice...doubt it'll take that much wood.....might want to have that water separate though and zoned off a daisy chain somewhere, so your not chilling your boilers water....

 

[Blazin]

First off if you get aggravated plowin your driveway a dozen times a year, you are'nt gonna like cutting 20 full chord of wood and feeding an OWB either I'm assuming. Heated floors in a building are the bomb no doubt, but throwing heat to a driveway is gonna eat some wood, Alot of wood as the others mentioned. That's a big bullet to bite just for snow removal on a driveway!

Ever think off movin south where they don't get snow? :monkey:

 

[flashpuppy]

I don't mind the firewood aspect of it. It's just that after 24+ hours of removing other peoples snow, I would like to not mess with mine when I get home. I know I would probably zone it separately. I would probably run some type of antifreeze in the driveway system, in case I'm out of town for a few days or something.

 

[Blazin]

How much snow do you move in Indiana? Holy crap man there's 48" plus in the woods here still with more on the way! I move ALOT of snow with the 6 plow jobs I do besides my own two 200yrd long driveways and parking areas.

It's just a way of life here I guess.

 

[trialanderror]

I don't mind the firewood aspect of it. It's just that after 24+ hours of removing other peoples snow, I would like to not mess with mine when I get home. I know I would probably zone it separately. I would probably run some type of antifreeze in the driveway system, in case I'm out of town for a few days or something.

if anything outdoor related i would highly recommend glycol...only because it's safe for the environment. expensive though. $1500 for a 55gallon drum....

i ran a steal and bought 4 of them from my buddy for $125 a drum Not sure how he ended up with them, but then again for that price i didn't care.

i think a 50/50 and your safe to -34*F? maybe -37? not sure, have to look it up again.

 

[newmanab]

Glycol

Trialanderror:

Do you ice melt? also if so how much sq2 ft?

What OWB? are you using and what else are you heating?






What does a hill billy say before he goes to the hospital?

Hey Watch this!!!!

 

[trialanderror]

not yet. i heat two homes. one is ~1800 and the other maybe 2200.
heating both hot water....

it's steel king 4300b, rated for 485,000btu/hr, but highly modified with water jacket ALL around it. had forced draft, i set it up with dual forced draft. it's got firebrick. orginally maybe 38 gallons of water, after i got done, nearly 90. fully insulated. 18" of batt on the top, 12" on the sides and bottom. each house has a 250gallon insulated tank. performs well for the boiler being free and $100 of steel welded to it.

honestly if i was to melt ice, i would keep the concrete just a few degrees above freezing, only because it's all that's needed. And i would try and set it up so it wouldn't chill the water the boiler is trying to heat. even though your trying to raise the ground a few degrees, it'll be droppoing the water the boiler is trying to heat several degrees, reason why you will burn so much wood.

ALl i could think is to have the ice melt go into a small water/water exchanger, and the water that's hot from the boiler QUICKLY pass through, so it'll keep it from freezing, but the return won't be such a significant drop....

or a zoning valve that'll creep open to let a few gallons circulate into the icemelt loop...i dunno, with alot of valves, sensors, pumps, and some mad scientist plumbing, i think you could melt ice and not burn an acre of wood.....

 

[mtfallsmikey]

Lots of contractors do snowmelt systems....I would run a separate zone with it's own pump, zone valve, etc. just like any other radiant system, only more of it!!...and yes, it will suck wood like a billion termites too!