Hot water pipe insulation

Hello all,

We have a Jean Pain-compost here made out of olive leaves manure, which has been giving us 60 degrees celsius water for 5 months. Right now the temperature is going down to 40 degrees at the moment.

So we are thinking to make a new one, and connect it to the house this time. There is one problem: there is no place right next to the house, so we have to make it further away.
We have a place about 4 meters lower than the house and at a 15 meter distance. We hope to get a thermosiphon working, the only problem is the heat loss from the pipes.


Does anyone know/have experience with insulation for hot water pipes and if it would be possible to get hot water inside after running 15 meters outside(in an insulated pipe)?

Kind regards,
Jeroen

Maybe...

Due to my concrete-on-grade foundation with radiant floor heating, I have to have my waterline going to my sheep barns right on top of the ground where it exits the house. In Maine, where it gets down to -25 below zero (f), that can mean frozen pipes.

A foot of sheep manure however has always taken care of the problem. Last year we got down to -30 below zero (f) for 3 consecutive weeks...and the water never froze. So if that is true, cold cannot get through, then heat cannot get out. I would try insulating the pipe with sheep manure. I am 99% sure it would work.

I'm not sure if they have outside wood fired boilers in Greece but the underground piping for them is an insulated cylinder with two water lines in it.  I think that would be perfect for your needs.  Here's the first one I googled:
Outdoor Furnace Supply.  
They even give heat loss per foot.  At 5 gpm it only loses 0.62 degrees F over 100 feet of distance.  

Thanks for the informative and encouraging replies. It will be difficult to get that kind of pipe here in greece, as no-one has outdoor furnaces, but I'm confident we can make something like that ourselves.

Travis: we don't have access to  a big quantity of sheep manure, but we can get a lot of horse manure, you think it has about the same insulation value?

I'll update here when the project continues.

Kind regards,
Jeroen

Dry soil is a moderately good insulator.  If you can bury the pipe 0.5 - 1 meter down, that would help.  To make sure the soil stays dry you can install an 'umbrella'  above it, basically bury a sheet of plastic just below the surface (and above the pipe) that slopes away from the pipe, so any water in the soil will be directed away from the pipe and the soil under the plastic sheet will stay dry.

As for the pipe in a pipe idea, you can build that yourself.  Just run the hot water pipe through a larger pipe, like a plastic drain pipe.  The outer pipe doesn't have to be anything special, even some used pipe will work. Every 2-3 meters add some kind of support(wooden bushing, etc.) to keep the internal pipe in the middle of the external pipe.  The air space between the two pipes will work as an insulator.  If you have access to cheap perlite or even some used Styrofoam, you could use that as both an insulator and a support for the internal pipe.

Be aware that if there is any chance that outside air will get into the outer pipe, then eventually you'll end up with condensation (water) inside the pipe and water is a poor insulator.  So you'll want to add some weep holes to the bottom of the external pipe to let the water drain out.  

Very informative article on the subject. I know a guy who loses half or more of the heat generated by his outdoor boiler..... no insulation on the building foundation perimeters (heated slabs) and hundreds of feet of fluid lines on 24/7 circulation.

https://woodstoves.net/blog/post/underground-insulated-pipe

frank li wrote:Very informative article on the subject. I know a guy who loses half or more of the heat generated by his outdoor boiler..... no insulation on the building foundation perimeters (heated slabs) and hundreds of feet of fluid lines on 24/7 circulation.

https://woodstoves.net/blog/post/underground-insulated-pipe

I honestly think the outside wood boilers were one of the silliest things ever invented. My father bought one, and he was a slave to it. Harsh words until you realize he was either trying to find wood for it, hauling wood to it, cutting wood up for it, or putting wood in it. Then rinse and repeat. It was stupid...then the darn thing burned his house down.

Travis Johnson wrote:

frank li wrote:Very informative article on the subject. I know a guy who loses half or more of the heat generated by his outdoor boiler..... no insulation on the building foundation perimeters (heated slabs) and hundreds of feet of fluid lines on 24/7 circulation.

https://woodstoves.net/blog/post/underground-insulated-pipe

I honestly think the outside wood boilers were one of the silliest things ever invented. My father bought one, and he was a slave to it. Harsh words until you realize he was either trying to find wood for it, hauling wood to it, cutting wood up for it, or putting wood in it. Then rinse and repeat. It was stupid...then the darn thing burned his house down.

They are run damped down between cycles and they smog the whole area where people run them. They can be a good machine, but i think the efficiency is harmed drastically by poor design integration.

If you used a high efficiency wood boiler to run full on until a batch of water was heated to usefullnes with plenty of storage, they could be applied to great effect.

Woodstoves burn out over time and a $1000 bill is easier to swallow than an $8000-$12000 one every 20 years.... or much less time. They warp and rot out and you need to dispose of barrels of glycol, im not impressed either. They are basically for large homes and farms with multiple outbuildings and keeping livestock water from freezing. Ranches, farms, resort sized homes and large workshops.

I prefer to watch my labor burning through our stoves neoceramic glass door, wood chippy floor and ash removal day be damned!

I agree they are inefficient, smoky wood eaters that have very few reasonable applications.  However, the piping they use for them could be the perfect thing for the OP which is why I incidentally brought them up.

Piping = Cool
Wood smolderers = Not Cool

jeroen joosse wrote:
Does anyone know/have experience with insulation for hot water pipes and if it would be possible to get hot water inside after running 15 meters outside(in an insulated pipe)?

It shouldn't be that cold in Greece. Olive leaves means no hard freeze, right? Well, there are prefabricated insulation readily available on the market. Depending on the size of your pipe, you will need to buy those long, cylindrical foams and duct tape them. I don't think that will be expensive in total since it is only 15 meters; but there is a quick and dirty solution. Bubble wraps are sold in round "bales", 1 meter in width and roughly 40 meters in length when opened (it should be like max 110 liras here in Turkey, something like 15-20 euroes ). You can cut 15 meters out of it and wrap around 6-7 times. There are different qualities available, some can withstand more than 60 degrees. Even the cheapest ones will get the job done though, no need to overthink.
I like to overdo works like these, I would have used the foam insulation and wrapped it with bubble wrap or buy sheet foam insulation and wrap it for million times.