# Heat loss on underground piping



## larryjbjr (Jun 25, 2017)

OK I was looking at this website
http://wood-heating-solutions.com/outdoor-furnace-parts/insulated-pex-pipe/

And I noticed that they claim 1.5 to 1.62° heat loss on their three wrap pex  tubing. I emailed Randy and asked him if that was both directions or just on the supply side and how much I would lose with only 50 feet run.

Here is his reply:

" at 50ft you would lose .62 degrees supply and return."

My response:

" so, 1.2 deg round trip?"

And his answer:

"No, hot water goes in cold water comes back the .62 is the hot water line the return cold water line has nothing to do with it."

Can somebody clarify this for me please? I thought the water returning was still hot and therefore if you lose temperature on the return it's still heat loss.



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## maple1 (Jun 25, 2017)

I'm not into mind reading but I think he means it would lose 0.62 per 50 feet. Which means supply & return would each lose 0.62 in their 50 feet run. That's how I would interpret.

I would also not buy that pipe or anything wrapped like it is - and find those numbers hard to believe.

Get good stuff - Thermopex or Logstor or that type. This is one place you don't want to cheap out, it will come back to bite.

IMO.


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## salecker (Jun 25, 2017)

Spend a bunch of time reading about underground piping.
I was going to buy the bubble wrapped junk.Then i started reading up on hydronics on this site.
I went with foam in trench method.I used Rehaul pipe and asked for at least 4" around each of my 4 pipes in the trench.
It was an expense,but should be a one time expense.


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## larryjbjr (Jun 25, 2017)

I'd like to get the good stuff, but my budget gives no room for that. 

It would be an extra $450 or so. I don't have an extra $450 right now, and the longer I wait in order to save up the $450 the more it will cost as I lose money paying extra propane while I'm waiting. 

I figure an extra cord of wood a year is better than an extra year of burning propane, at over $300/month...




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## hondaracer2oo4 (Jun 25, 2017)

The problem isn't that fact that the wrapped pipe may lose a little more heat than the logstor or thermopex. The problem is that ground water will end up in the lines. It might be 6 months from now or 5 years but it will happen! The black drain tile will get a small puncture(could even come that way from shipping, no way to see a small hole in that stuff ) and once water gets in you will go from burning 5 cords per year to 10 cords per year. You will have to dig up the pipe again and spend the money to buy the good stuff the second time. Do your self a favor and the extra work and spend the $450 because it is really cheap money at the end of the day.


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## maple1 (Jun 26, 2017)

larryjbjr said:


> I'd like to get the good stuff, but my budget gives no room for that.
> 
> It would be an extra $450 or so. I don't have an extra $450 right now, and the longer I wait in order to save up the $450 the more it will cost as I lose money paying extra propane while I'm waiting.
> 
> ...



We don't know anything about any of your system - but when it goes wrong it usually really goes wrong. Usually people end up digging it up & replacing, after a winter of constantly feeding their wood burner & the house being cold the whole time because the boiler water getting to it isn't hot enough. If it was a matter of simply burning an extra cord, that would be one thing - but when your house system needs constant 160+ water and it's only getting 150 max because your supply is losing 30 to the ground between the boiler and the house, that's another. Then there's also the creosote condensation & reduced boiler temp effect on the other end if the return water coming back into the boiler is only 100. Which then in turn lowers your boiler supply temps - a vicious circle typically resulting in at least doubling wood consumption. Not everyone experiences that every time of course, but it's happened a lot. Even if the run only loses a very optimistic (for that stuff) 10° each way, your boiler will struggle - with that 20, and another 20 dt for the house draw, that means your boiler will need to raise the water 40° under constant flow to maintain 180 out & keep return above 140 (point of condensation - does your boiler have return temp protection?). Quite hard to do. Things might be OK at first when everything is new, but moisture getting into that insulation is only a matter of time. The thin layer between supply & return lines will also lead to somewhat lower supply temps in the house, as heat want to transfer from the higher temp pipe to the lower temp pipe when they are next to each other.

Comes down to comfort, easier boiler operation - and peace of mind (what I'd consider the big one).


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## larryjbjr (Jun 26, 2017)

How can I tell if it has return temp protection?


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## salecker (Jun 26, 2017)

If it comes to just $450 extra that you need...
Yard sale some stuff that is collecting dust.Get a second job for a weekend.
Everything that Maple1 said should be seriously considered.


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## larryjbjr (Jun 26, 2017)

Unfortunately those things are not an option. I am already working all the overtime I can, plus trying to sell my AR, just to get the money to install it to begin with.

But I will take your advice to heart. Maybe for now I will just try to rig it up someway to get by through this winter.

It is only a short ways from my shed so maybe I will build some kind of  wooden trough and run some pex through there and insulate it real good to the shed then from the shed to the house just to get by this winter.

I don't want to bury something that is going to be inferior and cause me trouble later on. But I really cannot find the money to buy the good stuff and install it this year.


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## maple1 (Jun 26, 2017)

larryjbjr said:


> How can I tell if it has return temp protection?
> 
> 
> Sent from my iPhone using Tapatalk Pro



What do you have?

Typically there would be a bypass loop on the boiler - a pipe connecting just outside the supply outlet with just outside the return inlet. With either a separate pump & controls on that bypass leg, or a thermostatic valve T where it Ts into the return line combined with proper boiler pump location relative to the thermo valve location.

This is done to maintain 140 return temps entering the boiler. If they go lower than that for any amount of time, the cooler return water will cause excessive creosote condensation in the firebox which can cause the firebox to corrode from the inside out.


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## shawntitan (Jun 26, 2017)

Careful with that stuff, I have a friend who used the "bubble wrap in black drain pipe" stuff, must have a leak somewhere, he melts snow on a ten foot wide path from his house to his boiler, and it's buried DEEP. I used the spray foam in trench myself almost ten years ago and still have minimal heat loss.


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## salecker (Jun 27, 2017)

larryjbjr said:


> Unfortunately those things are not an option. I am already working all the overtime I can, plus trying to sell my AR, just to get the money to install it to begin with.
> 
> But I will take your advice to heart. Maybe for now I will just try to rig it up someway to get by through this winter.
> 
> ...


Building the above ground box is better than buried inferior lines.


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## Ashful (Jun 27, 2017)

larryjbjr said:


> "No, hot water goes in cold water comes back the .62 is the hot water line the return cold water line has nothing to do with it."
> 
> Can somebody clarify this for me please? I thought the water returning was still hot and therefore if you lose temperature on the return it's still heat loss.


I don't own an outdoor boiler, and really don't even know much about them, but I do know Physics.  So, take my answer below as theoretical, not based on experience, but physically accurate.

Heat loss is a function of the temperature difference between the heat source (your hot water) and the surrounding space (earth).  Double the temperature difference, and you will double your heat loss.  So, when numbers like this are given, they're at some assumed water and earth temperature, which are probably typical for your application.

The reason they might not specify temperature drop on the return line is that the temperature of the return water is much lower, and therefore the loss is so much less than that of the supply side that it is not a primary factor for system design.  If you happen to know your return water temperature, you could estimate it's loss as 0.62 times (Tr-Te)/(Ts-Te), where Tr is return water temperature, Ts is supply water temperature, and Te is earth temperature.


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## hondaracer2oo4 (Jun 27, 2017)

Yes, you are likely correct and appear smart enough to understand those concepts so you will also understand that throwing good money after bad is dumb. The problem again isn't the fact of how much the lines lose if they were tested side by side at the factory. It is when they get buried underground and when the ground water gets into the drain tile type pipe, at the point the lines are useless.


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## larryjbjr (Jun 27, 2017)

Anybody know anything about this stuff here? 

http://www.freeheat4u.com/REHAU-1-INCH-INSULATED-FOAM-FILLED-UNDERGROUND-PIPE_p_41.html


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## rowerwet (Jun 27, 2017)

You would probably be ok buying the cheap bubble wrap pipe, and installing it above ground in a box that would insulate it from the ground,  and protect it from UV and the elements. 
My own idea would be a layer of XPS foam between it and the ground,  and a luan box over it.
That way you won't be dealing with the ground water issues,  and won't be deep in debt.


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## rowerwet (Jun 27, 2017)

Oe even better,  a XPS foam box over it, completely isolating it from the elements and outside temps. 
Then seal it using this idea https://www.google.com/amp/www.inst...-make-nearly-anything-weatherp/?amp_page=true


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## rowerwet (Jun 27, 2017)

In my mind I would use 2 inch XPS for the ground layer,  with U shaped blocks every 6 inches to keep the pipe off the ground,  then 1 inch or 3/4" foam for the sides and roof.
With mor U shaped foam blocks to support the roof.
Then round the corners off and use PMF to seal it all into one weatherproof box.


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## rowerwet (Jun 27, 2017)

Like my foam kayaks idea https://www.google.com/amp/www.inst...sinkable-Foam-Kayak-Anyone-Can/?amp_page=true


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## maple1 (Jun 27, 2017)

larryjbjr said:


> Anybody know anything about this stuff here?
> 
> http://www.freeheat4u.com/REHAU-1-INCH-INSULATED-FOAM-FILLED-UNDERGROUND-PIPE_p_41.html
> 
> ...



Think it's the first I've seen of it, but it looks worlds better than that other stuff. Hopefully you'll get more input.


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## hondaracer2oo4 (Jun 28, 2017)

The rehau is the same as thermopex 1 inch but smaller in diameter than the logstor 1 inch equivalent. It is good high quality pipe, it's the shipping from free heat that will kill the price per foot.


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## maple1 (Jun 28, 2017)

Had a look around that site. I think I would be wary of buying something from them with the smoke & mirrors talk they have on there about other things, like boilers - but the pipe might be OK.

That site name is ringing a distant bell though, not quite sure why or if bad or good. Spidey sense says not good but without remember exactly, don't really know - so all could be well with getting some of their pipe.

I would go for 1-1/4" over 1" though.


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## larryjbjr (Jun 28, 2017)

maple1 said:


> I would go for 1-1/4" over 1" though.



I would like to go 1 1/4". But how would I crimp that? I think I'd spend more on the tool to crimp that than I'm prepared to spend


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## maple1 (Jun 28, 2017)

larryjbjr said:


> I would like to go 1 1/4". But how would I crimp that? I think I'd spend more on the tool to crimp that than I'm prepared to spend
> 
> 
> Sent from my iPhone using Tapatalk Pro



Not sure - would maybe be worth it to have someone come in with theirs just for that.

But aside from using that wrapped product above that usually leads to moisture intrusion, heat loss & replacement - likely the second most common problem with underground piping is undersizing it.


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## hondaracer2oo4 (Jun 28, 2017)

Logstor 1 inch is true 1 inch ID. It is the same size as 1 1/4 pex.


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## maple1 (Jun 28, 2017)

Also, did you read this?:

https://www.hearth.com/talk/threads/underground-lines-not-the-place-to-skimp.50506/


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## larryjbjr (Jun 28, 2017)

maple1 said:


> Also, did you read this?:
> 
> https://www.hearth.com/talk/threads/underground-lines-not-the-place-to-skimp.50506/



Yes, mostly. I can't say I read every word.

I mostly agree with it. But my wallet doesn't. 

I check the place freeheat4u.com and found that they are not very far from me. So I am planning to buy from them and then pick it up, that will save me the shipping.

Now a question. Most people problem with the five wrap pex is that it will leak eventually. So I am assuming if I put that inside a sewer pipe, so that It can never leak, then it is good stuff?





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## hondaracer2oo4 (Jun 28, 2017)

If you were able to get it into a "sewer" pipe(not sure what you are referring to) and it was water tight than yes the 5 wrap would probably be fine. The problem is trying to pull that pipe through the larger pipe. It will be close to impossible. Also 6 inch pvc is very expensive. At the end of the day it would cost likely close to the same as good pipe and you would never have any worries.


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## Tennman (Jul 7, 2017)

OMG!  Have you not read my horror story in the underground sticky regarding trying to do the underground on the cheap. I think I saw XPS mentioned above. Expanded polystyrene.... I seem to recall it not being closed cell and it being heavy and mushy when removed from being underground, meaning it sucked up water eventually like a sponge. If I didn't have the money to do the underground properly for this season, I think I'd temporarily use good split foam insulator and just keep it above ground like the large military bases and government facilities do. Energy loss due to hot lines being contact with wet dirt is a terrible thermal sink. I don't have time to do the math comparing good insulation but large temp difference above ground to less temp difference but terrible, wet insulation underground. My engineering instincts say well done temporary above ground is better than lousy underground.

This is a TRUE statement.... doing the underground once is miserable..... doing it twice.... well suddenly the price of propane becomes attractive.

Ok... I'll disappear again for a few months. Re-read the sticky.... years ago the topic of underground lines was my personal crusade to save the world. I've moved on to whirled peas.


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## larryjbjr (Jul 7, 2017)

Tennman said:


> OMG!  Have you not read my horror story in the underground sticky regarding trying to do the underground on the cheap. I think I saw XPS mentioned above. Expanded polystyrene.... I seem to recall it not being closed cell and it being heavy and mushy when removed from being underground, meaning it sucked up water eventually like a sponge. If I didn't have the money to do the underground properly for this season, I think I'd temporarily use good split foam insulator and just keep it above ground like the large military bases and government facilities do. Energy loss due to hot lines being contact with wet dirt is a terrible thermal sink. I don't have time to do the math comparing good insulation but large temp difference above ground to less temp difference but terrible, wet insulation underground. My engineering instincts say well done temporary above ground is better than lousy underground.
> 
> This is a TRUE statement.... doing the underground once is miserable..... doing it twice.... well suddenly the price of propane becomes attractive.
> 
> Ok... I'll disappear again for a few months. Re-read the sticky.... years ago the topic of underground lines was my personal crusade to save the world. I've moved on to whirled peas.



Yes I read the sticky. And I mostly agree with it.  I see that was about 7 years ago that you did that. Is it still holding up for you?

Please correct me if I'm wrong, but it seems like the whole point is to keep whatever you put down there well insulated and dry, primarily dry. The pex at freeheat4you.com seems to be well wrapped therefore would be insulated. So if I took that stuff and pushed it through a 6 inch drain pipe, not drain tile, drain pipe, which would keep it dry, wouldn't that be just as good as the foam in place?

If not, please tell me. I am not trying to be argumentative. I am by no means saying that I am right and everyone else is wrong. I really want to understand.






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## Tennman (Jul 7, 2017)

Yes, Over 7 years and the energy loss over about 340', no change... I seem to remember ~1.5*F over about 140' boiler to HX. I posted it's performance in the sticky. It varies somewhat based on the demand cycle, less loss on very cold days when it's cycling more frequently. I went to the freeheat site and only saw Rehau foam filled. I couldn't find a Coefficient of Thermal Conductivity for bubble wrap to compare to polyurethane. No joy. Did see a table saying R value of air space vs polyurethane; air =1, polyurethane = 7. I understand, you basically want to create a dry chase to keep cheaper insulated pipe in. When you add everything up what's the difference in time and dollars vs just foaming in place. Me? I don't ever want to dig up my yard again. Best wishes.


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## hondaracer2oo4 (Jul 8, 2017)

How much is 6 inch pvc per foot? I think it is somewhere around $4 per foot. That means that you are looking at right around the same price for good foam pipe per foot. 

As far as foam in trench method goes. I actually did this for 5 years myself. I too didn't have the money for good pipe and I wanted to run 4 one inch pex lines. So for $400 in pipe and $500 to foam the trench and my boiler I was in business. After 5 years I started to melt snow for about 20 feet from the boiler and then it would stop the melting. I believe the system was slowly absorbing water. When I built my garage and dug up some of the pipe to put the foundation, I found that the closed cell foam actually had absorbed water. When you broke off a piece and squeezed it water would come out. Now where this was done is very very wet. Likely water against the foam all year round. I stopped digging the trench at 3 feet when I hit ground water originally and set the pipes above that level but I bet the water rised to the pipes. 

This time when I built my garage and replaced the pipe to a new boiler pad placement I bought 100 feet of leftover pipe from someone else's install for $11 per foot. Two years ago my boiler would cycle once per hour or so with no heat more from the house, last year with the logstor the boiler would go over 4 hours without a load.


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## rowerwet (Jul 9, 2017)

Tennman said:


> OMG!  Have you not read my horror story in the underground sticky regarding trying to do the underground on the cheap. I think I saw XPS mentioned above. Expanded polystyrene.... I seem to recall it not being closed cell and it being heavy and mushy when removed from being underground, meaning it sucked up water eventually like a sponge. If I didn't have the money to do the underground properly for this season, I think I'd temporarily use good split foam insulator and just keep it above ground like the large military bases and government facilities do. Energy loss due to hot lines being contact with wet dirt is a terrible thermal sink. I don't have time to do the math comparing good insulation but large temp difference above ground to less temp difference but terrible, wet insulation underground. My engineering instincts say well done temporary above ground is better than lousy underground.
> 
> This is a TRUE statement.... doing the underground once is miserable..... doing it twice.... well suddenly the price of propane becomes attractive.
> 
> Ok... I'll disappear again for a few months. Re-read the sticky.... years ago the topic of underground lines was my personal crusade to save the world. I've moved on to whirled peas.


The post about using XPS was about running it above ground, not burried, and using it to keep the cheap wrap pex in a pipe from ever contacting the ground,  or having a larget delta between it and the air


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## heaterman (Jul 17, 2017)

Larry I'm going to tell you something you probably don't want to hear...but you need to hear it.

Reading through the thread here, I gotta say it'd be best if you could wait to do this job until you had the funds to do it right.
If there is one "line item" on an outdoor boiler install that I see people regret more than any other, it's the underground lines.
Invariably, when people are trying to save money, the line goes in undersized and skimpy on insulation. 
Both of those things will make you regret ever installing the boiler in the first place. I see it time after time after time.


The folks that put it in couldn't afford the good stuff any better when they redid their underground than when they put in the cheaper stuff to begin with.
I'm not trying to call you an idiot or anything like that. ... I've just seen so many people get turned off about burning wood because of poor system performance I couldn't even begin to count them up.

The laws of physics, heat transfer and fluid dynamics change for no man. Ever. They simply are what they are.

I'd like to see you happy with your results.


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## larryjbjr (Jul 19, 2017)

OK, thank you for the advice. I really do appreciate it.

But in the end, I've just got to do what I feel like I've got to do. So I went ahead and bought 80 feet of five wrap 1 inch  pex from a place local to me. I plan to put it this year in a wooden trough to protect it. Then, if it holds temperature decently, I will bury it next year. I am planning to add a second one next year anyhow and will just do both at the same time.

The place I bought it from assures me that it will only lose about 1.5° over 100 feet. If it does much worse than that I will return it. (I am a fighter and usually am able to hold people to their word).

I am so sick of paying so much for propane that I just cannot get myself to go another winter on propane. The pipe only cost me $300, so if I have to buy better stuff next year I should be in a better financial position to do so.

Please don't hold this against me in the future when I ask for advice. 

And if it proves out that I was wrong, Lord willing I will  return and confess my folly before you all and seek your forgiveness.


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## maple1 (Jul 19, 2017)

Did he say how long it would maintain the 1.5 loss? That's the kicker. It might do that brand new, but it's usually all downhill from there. Very interested to see how you make out , with periodic regular (and accurate) temp measuring all winter.

Good luck in any event.


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## heaterman (Jul 19, 2017)

So here's the math. Assuming it's actually 1.5* temp loss.

I'm guessing you'll be circulating around 8GPM so...

8GPM x 8.33 (weight of 1 gl of water) x 60 (minutes per hour) x 1.5 = heat loss of 5,997.6 btu/hour

5997.6 x 24 means you'll be losing 143,942 btu per day. 

Let's be charitable and assume you have a wood burner that will hit 40% efficiency giving you roughly 8.4MM btu per cord of wood burned.
8.4MM btu divided by that 143,942 = 58.36

So in a nutshell, every 58 days you will have lost an entire cord of wood into the ground. 

I hear what you're saying about your budget and can truly sympathize with you. 
I'm just saying, know your facts and make the best decision you can.


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## larryjbjr (Jul 20, 2017)

OK, based upon your numbers...

I need around 35,000 BTUs per hour to heat my house on average. Using your number, I will need 3 cords of wood a month to heat my house?

I really hope you're wrong. But I have a feeling that you're not.

That just means I'm going to have to work harder to get most of my wood for free or very cheap.

But still, if I lose 1.5° over 80 feet, and tennman loses 1.5° over 340 feet, then, while I may be less efficient, we both will use the same amount of extra wood for a month. So I'm no worse off than the person who puts their boiler further away from the house.

I know, that is assuming that I will only lose 1.5° heat loss. And if I lose more  I will return it. Or maybe next year if I am in better financial condition I can simply bury it and surround it with foam.




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## maple1 (Jul 20, 2017)

Have you done any flow calcs - do you know what your gpm flow will be? That means matching to a circulator that will deliver what you need. All kinds of cans of worms to consider up front when you start digging into it.

(Did the pipe seller fellow say anything about what GPM that 1.5 drop was 'good for'? If you flow less, you will see more temp drop, generally speaking - and less BTU being transferred overall).


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## larryjbjr (Jul 20, 2017)

maple1 said:


> Have you done any flow calcs - do you know what your gpm flow will be? That means matching to a circulator that will deliver what you need.


I have 83 feet one way, which figures out, using the normal rule of thumb, to be around 10 feet of head. Looking at my pump curve that will give me about 7 gallons per minute.


> All kinds of cans of worms to consider up front when you start digging into it.



You telling me! I have been surprised over the last couple years that I have been working on this how much there is involved in it! Looking back now I wish I had done  just about everything different.


> (Did the pipe seller fellow say anything about what GPM that 1.5 drop was 'good for'? If you flow less, you will see more temp drop, generally speaking - and less BTU being transferred overall).



I'm really not sure. I guess I could call them and ask.




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## Ashful (Jul 20, 2017)

larryjbjr said:


> OK, based upon your numbers...
> 
> I need around 35,000 BTUs per hour to heat my house on average. Using your number, I will need 3 cords of wood a month to heat my house?


Using Stevens Point climate data, and assuming your 35k BTU number is for your coldest month (Jan = 1614 HDD), your 3 cords per month would extrapolate to 15.6 cords per average (8385 annual HDD) year.  That's a metric buttload of wood, but not nearly as bad as assuming you'll be at 3 cords per month x 9 months.

I process a lot of wood, for my two woodstoves.  Possibly more than any two or three average stove-burning members of this forum, but thanks to augmenting my wood heat with oil heat, I've never exceeded ten cords burned in a year.  It can be real tough to fell, buck, haul, split, stack, move, and load that amount of wood, if you have any other demands on your time (eg. family), especially in those first few years when you're trying to collect maybe double your usage rate, to build a stockpile of seasoned wood.

Every situation is different, and as I said, I found a way to deal with my demand issue.  Others might have splurged for even bigger wood-processing equipment than I own, or found other ways to get their processing efficiency up, but it's real tough to beat what I have without spending some big money.

I'd go into this with the mentality that any reduction of your heating costs beyond one-third of your equipment investment is a success.  That way, you can be satisfied with a 3-year amortization your your investment, and not want to kill yourself with wood processing, trying to feed the beast.  It may be necessary to continue using some form of traditional heat, to keep the wood demand within your personal limits.


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## maple1 (Jul 21, 2017)

How much wood do you have ready to go for this winter?


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## larryjbjr (Jul 21, 2017)

None that is seasoned.

I've ordered 4 cords to be delivered next week. Plan to get more as I need it


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## larryjbjr (Jul 21, 2017)

I have access to a lot of dead elm. Last year I cut some and it measured in the mid to low 20s for moisture content. So, while not ideal, I'm hoping it will get me through the winter along with the wood I am buying.

Just waiting till I have enough time to go out there and cut it bring it home and split it.


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## larryjbjr (Jul 21, 2017)

I am also getting a lot of free wood from a local tree trimming business that I expect to take care of me next year.


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## Highbeam (Jul 21, 2017)

heaterman said:


> Let's be charitable and assume you have a wood burner that will hit 40% efficiency



That seems really low. Is that 40% number correct? I thought the wood boiler guys were getting very high numbers.

The OP wouldn't disclose which boiler he is using....


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## TCaldwell (Jul 21, 2017)

Unfortunately most outdoor wood boilers have a efficiency rating between 28 and 40 pct!


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## maple1 (Jul 21, 2017)

Highbeam said:


> That seems really low. Is that 40% number correct? I thought the wood boiler guys were getting very high numbers.
> 
> The OP wouldn't disclose which boiler he is using....



Pretty sure it's ballpark for an ordinary OWB. That's without losing heat to the ground....


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## TCaldwell (Jul 21, 2017)

In my neck of the woods ironically the owb's have taken to lg green rounds because they last longer, further reducing any chance of efficiency. The log piles are right next to the boiler with no splitter in sight


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## Ashful (Jul 21, 2017)

I assume this is why I hear so many boiler guys talk about 20+ cords per year, whereas most woodstove operators run 3-4 cords per year.  My stove is rated 80% - 86%, depending on burn rate.


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## larryjbjr (Jul 21, 2017)

*sigh* I was told it would use a lot more than my wood stove, but I never dreamed it'd be that much.

Maybe I should just sell it while I can....




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## larryjbjr (Jul 21, 2017)

Highbeam said:


> The OP wouldn't disclose which boiler he is using....



No secret. It's a Johnson Little John. About 17 years old.

I got it last month for $500.











Pretty good shape for its age I think.


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## Bad LP (Jul 21, 2017)

That's a lot of wasted energy IMO not to mention the personal time and effort cutting wood.


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## Ashful (Jul 21, 2017)

larryjbjr said:


> *sigh* I was told it would use a lot more than my wood stove, but I never dreamed it'd be that much.
> 
> Maybe I should just sell it while I can....
> 
> ...


Don't take my word for it, I've never owned an OWB.  Just regurgitating things I've read here.


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## salecker (Jul 22, 2017)

One of the problems with efficiency and outdoor wood boilers is almost everything that burns wood outdoors is lumped in as a OWB.
 Boilers are a closed system and run under pressure.
 Wood fired water heaters are an open system.
 My Econoburn is a boiler that was designed to use indoor or outdoor.Under the skin the inside and outside models are the same.The efficiency of the Econoburn is claimed to be in the 80's percent.
 A Garn is a wood fired water heater,no pressure open system.From what i have read it would be hard to top it's efficiency and simplicity.
 Then there are many others that ride the coattails of quality OWB's and Outdoor wood-fired water heaters.They can usually be singled out because they have a huge firebox that the owners usually fill up with anything that will smolder, most of the time it's wet wood because dry wood disappears in them.
 Our town has a big "Central Boiler" OWWH that tries to heat a cafe and motel.It is the biggest one they make.There is always a huge smoke cloud coming from it.Right now there is a huge pile of green popular that will be fed into it this fall/winter.They used bubble wrapped lines which are exposed without insulation where they come out of the ground and go into the buildings with a 90 fitting.
 From October on i fill the oil tank at the Motel every 2 weeks because the motel will run out of fuel if it gets cold.These aren't big buildings,old yes but have had some insulation upgrades and window upgrades.They burn/smolder about 30 cords a winter plus the oil.There is creosote running down the short little chimney,and out around the door.Totally inefficient system that costs them more to use to heat the place then if they used all oil.
 This business was my mom's,it is leased out.Previous owners(they had a contract to buy the business but weaseled out of the contract) had the "Central Boiler" installed by a company that went out of business.My Mom died and it is now my brothers and I's headache.I really hope this batch of Chinese people actually step up and pay for the place(another agreement of sale).
 If for some reason we ever have to heat the place the OWWH will never see another stick of wood.


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## StihlKicking (Jul 23, 2017)

TCaldwell said:


> Unfortunately most outdoor wood boilers have a efficiency rating between 28 and 40 pct!



I know my OWB is very inefficient compared to most in door wood stoves but I have a hard time believing it's that low. I'm guessing mine is more like 65ish. 2800 sqft, well insulated, 10 cords a year burning 365. If anyone can run numbers to know the efficiency of my OWB for sure I would really appreciate it.


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## maple1 (Jul 24, 2017)

StihlKicking said:


> I know my OWB is very inefficient compared to most in door wood stoves but I have a hard time believing it's that low. I'm guessing mine is more like 65ish. 2800 sqft, well insulated, 10 cords a year burning 365. If anyone can run numbers to know the efficiency of my OWB for sure I would really appreciate it.
> 
> 
> Sent from my iPhone using Tapatalk Pro



Sounds like about the same size as my house - which is 2700 sq.ft. in two stories, plus another 1500 in the basement (unfinished & not directly heated), 'typical' 20 year old construction. I burn between 5 & 6 cords. Going all summer would be maybe another cord. I think my boiler is rated around 80%. Not sure they can be directly compared though, likely some apples & oranges stuff going on.


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## larryjbjr (Jul 24, 2017)

maple1 said:


> I think my boiler is rated around 80%.



Which boiler do you have?


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## larryjbjr (Jul 24, 2017)

I've heard that you can improve efficiency by lining the firebox with fire brick. 

Anyone know if there is any truth to that?


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## maple1 (Jul 24, 2017)

larryjbjr said:


> Which boiler do you have?



It's in my sig - Varmebaronen UB 40.


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## larryjbjr (Jul 24, 2017)

OK, sorry I don't see any signatures using phone


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## maple1 (Jul 24, 2017)

larryjbjr said:


> I've heard that you can improve efficiency by lining the firebox with fire brick.
> 
> Anyone know if there is any truth to that?
> 
> ...



Maybe?

The thing about boilers vs. stoves & furnaces is - they have a liquid cooled firebox. That's a way of looking at them that many don't take. So the water jacket, while necessary for heat exchange in a 'conventional' boiler, is also a hindrance to a good hot fire. A fundamental design aspect of most efficient boilers (gasifiers) is separating the insides into 3 'zones' if you will - first is the firebox where the primary fire is, then a secondary chamber completely surrounded by refractory where the gases from the first fire pass to and can fully combust without the liquid cooling effect, then on to the heat exchanging area where most of the heat recovery takes place via heat exchange tubes.

So - if the inside of the firebox on the conventional boiler is big enough, you may be able to play with some firebrick to build a chamber around the fire where most of the burning can take place, then if the gases can still pass by the metal (heat exchanging) surfaces of the firebox from there before they go up the chimney, you might get some improvement. But you could also be making a creosote trap doing that, if your return water coming back to the boiler is less than 140° for periods of time. Maybe you will get some feedback from someone who has just simply lined with success.


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## larryjbjr (Jul 24, 2017)

I think I'm just going to sell this thing. So I just put it on craigslist.

Anybody around the Sheboygan Wisconsin area looking for an outdoor wood boiler? [emoji16]


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## StihlKicking (Jul 24, 2017)

Not from there and not looking but I just like saying Sheboygan! [emoji3]


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## Ashful (Jul 24, 2017)

Running the Englander again this winter?


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## larryjbjr (Jul 25, 2017)

Ashful said:


> Running the Englander again this winter?



Yes, definitely planning to run that this winter. 

But, I was thinking if I could just sell the outdoor wood boiler and everything for at least what I have in it then I would buy a new high-efficiency LP boiler. I have a friend in the HVAC business who has offered to sell me one at cost. Just waiting now for him to give me a quote on how much that will be.

I really like the idea of an outdoor wood boiler. But I just don't think I'm ready to handle 15 cord of firewood a year. Especially since this year I will have to buy almost all my wood. At $150 per cord, I won't be saving any money.

Now, in a few years when my boys are old enough to do most of the work I might just get back into it. [emoji16]


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## Ashful (Jul 26, 2017)

I really know nothing about them, other than the folks I've known who own them seem to love 'em, but what about an indoor wood boiler?

LP is convenient, but it ain't cheap around here!  I pay far less per BTU for oil, than I've ever seen quoted for LP.


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## larryjbjr (Jul 26, 2017)

Ashful said:


> I really know nothing about them, other than the folks I've known who own them seem to love 'em, but what about an indoor wood boiler?
> 
> LP is convenient, but it ain't cheap around here!  I pay far less per BTU for oil, than I've ever seen quoted for LP.



I don't really know much about indoor wood boiler. But I have thought about a wood furnace. Actually my friend is selling one for a reasonable price. But, I would still need wood for this winter and I just don't have anything ready to go yet.

Around here we had a really wet spring and early summer. Plus with me working a lot of overtime I was never able to get out and get firewood. So I think for this year I'm just gonna have to heat with propane again.


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## leon (Jul 26, 2017)

larryjbjr said:


> I've heard that you can improve efficiency by lining the firebox with fire brick.
> 
> Anyone know if there is any truth to that?
> 
> ...





===========================================================================================================


When I had my indoor wood boiler I filled the fire box half full of full firebrick to the flue breech after I laid a 2 by 12 by 12 piece of channel iron over my shaker grate frame and after doing this I had a hotter fire with less smoke and I wish I had done this in 1983 when I had the boiler installed.

You will see a huge reduction in wood burning once the firebrick gets hot it will burn the gasses that are normally lost when burning and you will have less smoke.

I will be adding firebrick to the coal stoker boiler this year as well.

At the rate your going you will  be better off building an 83 foot long pipe supported trellis to grow grapes on  and also carry the tubing in a narrow closed box made with 2" by 8"s for the top and side and bottom that would have the tubing foamed in place in the wood box made from pressure treated lumber..


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## larryjbjr (Jul 28, 2017)

heaterman said:


> So here's the math. Assuming it's actually 1.5* temp loss.
> 
> I'm guessing you'll be circulating around 8GPM so...
> 
> ...



I'm not sure I understand this part. Why would you multiply that times 24 hours when the pump will not be running 24 hours.

Typically my furnace runs less than 20 minutes per hour. So that would be multiplied times eight hours right?




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## maple1 (Jul 28, 2017)

Most OWB people run their pumps 24/7. I don't think you can directly correlate current furnace run times with OWB circulation times - for most of the heat loss and inefficiency reasons already talked about. Together with - the direct heat your LP furnace can supply in 20 minutes is bound to be a lot more than an OWB exchanger (absolute max maybe 180°?) can supply in those same 20 minutes.


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## NP ALASKA (Feb 17, 2018)

I owned a CB 7260 for about 7 years in the Interior of Alaska.
4 buildings- over 11,000 sq ft
Pumps run 24/7 
One run was 150’ underground with another 120’ inside building

70 cord per year

Sold it and ran as quick as possible

I compare the stack output of that old unit and my Effecta gasser- no comparison 
The OwB is obviously a non efficient device


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## JohnDolz (Feb 17, 2018)

NP ALASKA said:


> I owned a CB 7260 for about 7 years in the Interior of Alaska.
> 4 buildings- over 11,000 sq ft
> Pumps run 24/7
> One run was 150’ underground with another 120’ inside building
> ...


Face Cord or Full Cord? Either way 70 is a crazy # !


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## warno (Feb 17, 2018)

larryjbjr said:


> OK, sorry I don't see any signatures using phone
> 
> 
> Sent from my iPhone using Tapatalk Pro



Turn your phone sideways.


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## NP ALASKA (Feb 17, 2018)

JohnDolz said:


> Face Cord or Full Cord? Either way 70 is a crazy # !


Full cord
Was a vicious few years


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## NP ALASKA (Feb 17, 2018)

Id collect about 10 and have 5-6 10 cord log trucks delivered.
Cut in 36” pieces and feed the dragon over and over.


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## salecker (Feb 18, 2018)

JohnDolz said:


> Face Cord or Full Cord? Either way 70 is a crazy # !


I know a guy that has a Central Boiler of some sort.
He heats his house which is quite similar to mine and his garage and can heat one other building if it is required.
He goes through over 50 real cords a winter.For a number of years he worked at a sawmill so he would haul home the scrap wood from their yard.Now he has a real chore to process his wood for a year.
I would run for over 5 yrs on 50 cords.


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## JohnDolz (Feb 18, 2018)

NP ALASKA said:


> Full cord
> Was a vicious few years


Wow! Cannot even imagine.


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## JohnDolz (Feb 18, 2018)

NP ALASKA said:


> Id collect about 10 and have 5-6 10 cord log trucks delivered.
> Cut in 36” pieces and feed the dragon over and over.


Was thinking about you during that 2 week stretch we had where it stayed well below 0 degrees F - could not believe how much wood I was burning through. Had me thinking pellet boiler for a house we are considering about in VT.


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## NP ALASKA (Feb 18, 2018)

T


JohnDolz said:


> Was thinking about you during that 2 week stretch we had where it stayed well below 0 degrees F - could not believe how much wood I was burning through. Had me thinking pellet boiler for a house we are considering about in VT.


The pellet option on my boiler is pretty nice.
I travel once in a while and it makes it easy for the wife and kids; ran two weeks solid on pellets once.
They just had to add to the half ton hopper.

If I was looking at another place I would still go pellet / wood combo like I have now.  I like the option to do either. 
Just my 2 cents

My new install seems to be taking shape; I will have a underground run to one building that is 45’. Im thinking of running a supply-retrun diferential pump on it- instead of a pump running constant.


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## JohnDolz (Feb 19, 2018)

NP ALASKA said:


> Id collect about 10 and have 5-6 10 cord log trucks delivered.
> Cut in 36” pieces and feed the dragon over and over.


Was thinking about you during that 2 week stretch we had where it stayed well below 0 degrees F - could not believe how much wood I was burning through. Had me thinking pellet boiler for a house we are considering about in VT.


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## JohnDolz (Feb 19, 2018)

NP ALASKA said:


> T
> 
> The pellet option on my boiler is pretty nice.
> I travel once in a while and it makes it easy for the wife and kids; ran two weeks solid on pellets once.
> ...


Interesting, for some reason I thought you used Wood in the shoulder seasons and pellet in the real winter portion. As I am considering a 2nd home having a pellet backup at both locations seems to be worth exploring. Any chance I can ask you for some pictures of what the Effecta looks like with the pellet system in place? Feel free to email me those at your convenience so we are not boring everyone.

Regarding your plumbing from an outbuilding, you should poke TCaldwell & nhtreehouse they are both experts on that subject.


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## huffdawg (Feb 21, 2018)

maple1 said:


> Sounds like about the same size as my house - which is 2700 sq.ft. in two stories, plus another 1500 in the basement (unfinished & not directly heated), 'typical' 20 year old construction. I burn between 5 & 6 cords. Going all summer would be maybe another cord. I think my boiler is rated around 80%. Not sure they can be directly compared though, likely some apples & oranges stuff going on.


What temp do  you keep your house at Maple?


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## rowerwet (Feb 23, 2018)

NP ALASKA said:


> I owned a CB 7260 for about 7 years in the Interior of Alaska.
> 4 buildings- over 11,000 sq ft
> Pumps run 24/7
> One run was 150’ underground with another 120’ inside building
> ...



Did you have good underground lines? (The ground stayed frozen over them all winter? )
That kind of wood burn is crazy!


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## maple1 (Feb 23, 2018)

huffdawg said:


> What temp do  you keep your house at Maple?



It varies a bit. We have 4 zones. And use various setbacks.

One of the 4 is kids bedrooms, and they're all off to college now, so it stays at either 16 or 17c, unless they're back for a visit. Master bedroom zone sets back to 16c around 6am, sets back up to 20c at supper time. Back down to 18c around 10pm. Living room/office is still on a manual stat, I turn it down a bit when we go to bed (18c?), back up a bit (20c) when I get up if I am home all day. Maybe give it another nudge up around suppertime. Last zone is kitchen. It sets up to 20c at 5pm, down to 16c at 9pm, up to 18c at 6am for a couple hours than back to 16.

Or thereabouts.

That usually puts most of my heat load on my boiler when it is running - set temps rise not long after I light. And lets storage coast further when I'm not. Oversized radiation/distribution is pretty much a necessity for good setback recovery. If it is extra cold out or everyone is home for the day all around the house I will just turn the heat up more. Kitchen zone also has good sun exposure. Right now it's around -5c and sunny out and 21c out there with stat set at 16. But with no wind. Wind hits us pretty hard, really bumps the heat loss up even though we have fairly decent construction.


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## NP ALASKA (Feb 25, 2018)

rowerwet said:


> Did you have good underground lines? (The ground stayed frozen over them all winter? )
> That kind of wood burn is crazy!


Therma-pex from Central boiler- buried 4 1/2 - 5’ deep. Frost line reaches anout 3’ here.

Heating 4 buildings over 11000 sq feet had a bunch to do with it


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## Ashful (Feb 25, 2018)

NP ALASKA said:


> Therma-pex from Central boiler- buried 4 1/2 - 5’ deep. Frost line reaches anout 3’ here.
> 
> Heating 4 buildings over 11000 sq feet had a bunch to do with it



Sounds like a lot, but the numbers do check out.  I’d expect 400M-500M BTU to heat that space, in our 5000 HDD climate, so almost triple that in your 14k HDD climate.  That’s 42-63 cords, depending on species, at 100% efficiency.  Scale for boiler efficiency and line loss, and 70 cords sounds just about right.


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## vtwoodheater (Feb 25, 2018)

I lined my OWB firebox with 2" firebrick, it made a hot fire for sure, but since most of the designs are straight through and out anyway, probably didn't gain much transfer to the water.

I used a viridian delta T pump in my basement next to my plate exchanger for the last year I had my OWB.  I controlled it with the end switch on the taco zone relay.  It only ran when heat was needed. With one zone calling, it ran around 20 watts, with 4-6 zones calling it ramped up to full speed of 68 watts.  Saved on electric consumption and wood usage for sure.

*The calculation that would make you vomit would be how many BTU's are lost to the outdoors from the OWB itself just sitting out in your open yard all winter long.*


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## NP ALASKA (Feb 25, 2018)

Ashful said:


> Sounds like a lot, but the numbers do check out.  I’d expect 400M-500M BTU to heat that space, in our 5000 HDD climate, so almost triple that in your 14k HDD climate.  That’s 42-63 cords, depending on species, at 100% efficiency.  Scale for boiler efficiency and line loss, and 70 cords sounds just about right.


Nice- no engineer here - Thanks for the confirmation. I just gain experience and wisdom through application
At the end of the day I am so glad I found thia site and my Effecta gasser.
Regards


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