Question about Outdoor boilers

[Mtnjack]

Remember insulation only slows heat transfer, does not stop it,just have to start mowing before every one else.I heat with a taylor 165 feet from house and lose 10 to 20 degrees,180 to 160 not a problem. Just taped bbq meter to pipe in basement.House is plenty warm. Mtn Jack

[doctorb]

I had a long run from my shed to the house >250 feet.  Had CB pex pipe 3-4' deep.  I also had the ground "appear" over the course of the underground lines after a snow.  But this took some time to show up.  I lost 10-12 degrees from the OWB to my basement.   Set the boiler at 180-195 to deliver 180 degree water to my basement.

Since the system loses heat continually over weeks and months, I am not surprised there is demonstrative heat loss and ground warming/snow melt.  While I lamented this inefficiency, I think it's impossible to reverse this process.  Overbuilding the system with uber-insulation at the time of installation may help, but, as was said, wood is relatively cheap.  I have not heard of any OWB owner complain that their system doesn't do the job because of ground related heat leak.

[doc henderson]

a cord of hedge is 32,000,000 BTUs.  Cottonwood is 18,000,000 BTUs.

[Sod saw]

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doctorb,       It seems to me that 12 degrees is a lot of loss.  Especially over the long cold months that we have.  And at our age, how much longer can we cut our own wood.  I have thought about a heat pump for the family as I get on in age.

Have you thought about insulating your pipes from boiler to house?

If you were to dig up your pipes, not all the way, only half as deep as the pipes actually are.   Then install 2 inch closed cell foam so that the insulation extends 2 feet from each side of your pipes.  Yes that is 4 feet wide trench and foam.  The closer to the pipes the better.

Cover the foam with the dirt that was removed. You should see an improvement in water temperature at the house.

Now, having said all that, 250 feet is a long way and using expensive foam and digging (unless you have an excavator yourself).  You will need to do the math and take into consideration how many more years the system will be used by your family. 

My physicians all have been notified that they will keep me going for another 40, or so, years.

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[doc henderson]

temp (heat) always moves to a lesser temp.  so, you might stop it going up, but at 180° it will go down and sideways until it is all the same temp.  insulation slows it down.  a faster flow will drop less but in reality you are supplying more heat per minute so less drop in temp.