Outdoor Wood Furnace Info

General => General Discussion => Topic started by: racnruss on February 11, 2015, 08:16:56 PM

Title: Underground pex for heat without a boiler?
Post by: racnruss on February 11, 2015, 08:16:56 PM
Could you heat a 40x60 Morton building up to say 45 Degrees F and keep it there in cold weather (Iowa) with just a loop in the ground and circulating pump?

Assuming its insulated of course.
Title: Re: Underground pex for heat without a boiler?
Post by: Jwood on February 11, 2015, 08:21:39 PM
No way I don't see it happening.
Title: Re: Underground pex for heat without a boiler?
Post by: Bondo on February 12, 2015, 06:37:40 AM
Could you heat a 40x60 Morton building up to say 45 Degrees F and keep it there in cold weather (Iowa) with just a loop in the ground and circulating pump?

Assuming its insulated of course.

Ayuh,...   A loop of pex with cold water runnin' through it ain't gonna heat nothin',......

A single loop in the ground ain't gonna heat a buildin',...

Without a proper pattern in the slab, 'n Hot water circulatin' through it, yer not gonna heat anything,...
Title: Re: Underground pex for heat without a boiler?
Post by: mlappin on February 12, 2015, 09:08:43 AM
I don't think you'll get it up to 45, you might keep it above freezing though.

I've read several articles on snow melt systems that for every foot of pex in the cement you bury a minimum of two feet of pex in the ground several feet below the deepest expected frostline. Here in indiana it would be at least 7 feet deep. This type of system is being used in a lot of europe and in Minnesota as well.
Title: Re: Underground pex for heat without a boiler?
Post by: farmboythegreat on February 12, 2015, 09:36:01 AM
maybe , if you get pressure ( 2000 psi ) and lots of flow 
Title: Re: Underground pex for heat without a boiler?
Post by: willieG on February 12, 2015, 10:06:42 AM
500x GPM x temp change (difference between water entering the heat exchanger and water leaving the heat exchanger) = btu per hour output of exchanger

i am uncertain of how much heat would be pulled from the exchanger with say only 25 degrees difference between room temp and water temp ( 30 room and 55 water)

as water temps lower the amount of btu drawn from the exchanger go down

as someone stated you might gain a few degrees on mild days but i doubt you could match the heat loss of the building on cold  or windy days

if we said  you could pump 10 GPM at 55 degrees and you could (just guessing) draw out 4 degrees

500 x 10 x 4 =  20000 x  = 20000 btu per hour devided by the square footage of the room 60 x 40= 2400=8.3 btu per hour per square foot. I would make a guess your heat loss is at least this (but it is just a guess)

I have an in ground water furnace (now as back up to the wood)  i can tell you that I have 3,500 feet of 1.25 pipe in the ground to reclaim enough ground heat to keep the furnace supply at the true ground temp.

even with the type of furnace i have that compresses the water to get the heat from it i was told that the blower must blow a lot more than a regular blower as the heat coming out of the registers will only be about 7 degrees more than the room temp (that is why i guessed you might get 3 or 4 as you are only moving water not compressing it and that 4 degrees may be a high estimate?)

this is all just guessing on my part but it may give you some ideas as to what to search out for more information?
Title: Re: Underground pex for heat without a boiler?
Post by: atvalaska on February 12, 2015, 01:41:26 PM
NASA time....
Title: Re: Underground pex for heat without a boiler?
Post by: fireboss on February 12, 2015, 09:13:22 PM
A friend has a morton building with no heating system at all and it is 50 or 55 all winter long  I think he put double insulation   
Title: Re: Underground pex for heat without a boiler?
Post by: aries9245 on February 14, 2015, 04:45:13 AM
I'd say closed cell spray foam! U heat with a match
Title: Re: Underground pex for heat without a boiler?
Post by: Jwood on February 14, 2015, 09:09:01 AM
A friend has a morton building with no heating system at all and it is 50 or 55 all winter long  I think he put double insulation

He wouldnt get by with that in MN eventually it would freeze in his building.
Title: Re: Underground pex for heat without a boiler?
Post by: willieG on February 14, 2015, 12:27:51 PM
it was 10 F outside with a wind chill of below 0 , my 30 x49 shed with 2x6 walls with pink insulation and 12 foot ceilings with 2x6 pink between the joists and 12 inches of blown in cellulose, my shed was reading on the outside walls 30 degrees there were some puddle sunder my old truck so it was just above freezing 2 feet from the floor away from the walls.no heat on
Title: Re: Underground pex for heat without a boiler?
Post by: racnruss on February 14, 2015, 01:43:46 PM
I posed this question because I'm moving to a property that has a 40x60 building that is about 150 feet NW of the house.  Initially I thought about putting boiler by the building and heating floor and running underground to the house.   Now, I'm thinking that prevailing winds are going to bring smoke right at the house most of the winter.  So, other option is to put boiler E-NE of the house but then I'd bee like 200' to the building and 75' from the house.

The building will be storage for equipment with (hopefully) little mechanic work in it.  So 45 degrees would be just fine.
Title: Re: Underground pex for heat without a boiler?
Post by: Bud Man on February 15, 2015, 08:45:41 PM
Congrats on the new property Russ. Been wondering how it turned out for you. Come take a look at my set-up, not the same but it might give you some ideas.
Title: Re: Underground pex for heat without a boiler?
Post by: willieG on February 15, 2015, 09:25:06 PM
do yourself an experiment...get a blower and rad that you would use in your shop, when the outside temps is 30 or below run your garden hose through the exchanger and measure  how much heat you are taking out of the water. your garden hose is likely 2 or 3 gpm. that should give you an idea of what you could expect?
Title: Re: Underground pex for heat without a boiler?
Post by: slimjim on February 16, 2015, 02:19:44 AM
Nice experiment willieG :post:
Title: Re: Underground pex for heat without a boiler?
Post by: mlappin on February 16, 2015, 06:15:28 AM
do yourself an experiment...get a blower and rad that you would use in your shop, when the outside temps is 30 or below run your garden hose through the exchanger and measure  how much heat you are taking out of the water. your garden hose is likely 2 or 3 gpm. that should give you an idea of what you could expect?

I think you should have more than 2 or 3 gpm out of a garden hose unless it's all 1/2 hose. Just take a few 5 gallon buckets and time how long it takes to fill both of them then do the math.