Question: Pre planning boiler system

[gonediesel]

Hello, new to the forum with a few questions. I am in doing some landscaping around our home and needed to install a sump drain to the outside of the house from a utility area in the basement. This required digging a 4-5ft deep x 20ft trench under a covered porch that only had a foot and a half ground clearance. This was such a huge joy that I don't think I handle this much fun again. So while its opened up I would like to run anything needed for a future boiler install. My question is if you were to have the ground opened up and have the ability to pre run what ever your hearts content to a boiler system, what would it be?



Specifics on the house and system:



Our home has three in floor zones. One is the garage which I really don't think I would heat but it may be an option. I have an electric hot water heater I would run an side arm exchanger off of and then also into a forced air system. The house is about 4000sq/ft. The plan would be for a gasification boiler system placed in it a pole barn about 150ft away. I would have a 1000 or so gal heat sink. I have a buddy who spray foams and would go that route for the run to the barn/heat source.



I talked to two local installers (NW WI) and both say only one run from house to barn/heat source. One said to run a water line to have fresh water access at the storage and stove. Both said no additional wiring other than power. I thought there has to be some other low voltage stuff to run? I am kind of a geek with stuff like this so I would like to know what else should be ran? Temp monitoring? Networking?



What I am working on right now:



- One run of Thermopex from the basement into the trench and ran 20ft under the porch (4ft deep in ground) and it will terminate about 5ft into the yard for future use. I can't get my buddy to spray foam a short run like this right now he is busy with good paying work. I am going to run to Menards and see if they have a 5” flexible tubing of some sort that I could run over the Thermopex and spray canned foam to add a little insulation where the Thermopex is exposed to air as it exits the house and enters the ground under the porch. Not sure if this is over kill. I did see a thread on the forum here where the Thermopex didn't melt snow it was exposed to.



- One 3/4” pex water line inside a 3” PVC filled with canned spray foam into the ground 4 ft deep and from there the pex is unprotected and ran out to the same area in the yard.



- One 3” PVC empty for what ever I usually wish I did once I have sealed everything up.



- One 2” PVC conduit to run power to boiler.



Thanks for any input and suggestions. I will post a write up once I am finished for future newbies like me.

 

[E Yoder]

Not sure I'd want to splice underground later. No need for control wire as it's just a continuous run pump on the main loop to the house. All secondary loops are inside.

 

[maple1]

I would definitely avoid any underground splices.

 

[gonediesel]

OK thanks for the reply. I am going to rethink this. There was another issue that came up. My wife picked up the short run of Thermopex and I threw it in the yard after looking and messing around trying to bend it. I had a piece of 3/4" pex for water line I was cutting and running and happen to think about the size of the Thermopex tubing and was thinking looked the same size or smaller than the 3/4 pex. Sure enough and confirmed here that stuff is misleading. So I am considering running 3 inch PVC pipe that I can stuff to pex lines into at a later date. I could insulate them and wrap with aluminum tape for the 20 ft section and spray foam a few feet of the end to seal it up. I read some review of the Thermopex and thought it would be easy to drop that in the ground but I don't want to worry about restriction and then the possibility of a underground leak in the splice. I have a large utility box that I was going to bury above the splice to check on it but again thats something that would be nagging in the back of my head every night while trying to goto sleep.

 

[salecker]

Rehue tubing has splices that are made to be buried
At least that was what i was told. I have 4 underground.All i could get was 100 ft rolls,my run is just under 125 ft

 

[maple1]

The catch is that unless you use Thermopex (or similar of other brands), you will likely be looking at heat loss to the ground at some point. If not right away, it will likely happen gradually over time as moisture works its way into the insulation you use.

 

[coolidge]

You can't use the cans of foam in the ground, it will be like a sponge.
Even closed cell foam should have a good thick vapor barrier if in the ground.

 

[E Yoder]

3" PVC is only big enough for two ¾" pex with fairly minimal insulation. With no 90's.
I'd go bigger and keep it straight, with a pull rope.

 

[maple1]

Is the pole barn already there now?

Might be time to doo doo or get off the pot, as they almost say, and go all the way & run the whole business now. I would not go less than 1" for a 150' run tho, and 1-1/4" might even be a consideration. It will be pricey no matter if Thermopex or foam in trench (which I think you said were also thinking about?)

One off the cuff thought out there idea - what about the prospect of setting a 4' high or so cleanout riser in place in the ground just far enough out from the house to clear your deck etc. and running the short stuff you were thinking about running 'for now' into that? Then in the future if/when you decided to go all the way, you would have a dry place for the long stuff to meet the short stuff and do the work needed to connect them. Or just run a short piece of nice big say 6" or 8" sewer pipe between it & the house that you could fish whatever thru later? (If a straight run).

 

[gonediesel]

Thanks guys for all the replies. I should have started this thread sooner. Ok to answer some questions

The catch is that unless you use Thermopex (or similar of other brands), you will likely be looking at heat loss to the ground at some point. If not right away, it will likely happen gradually over time as moisture works its way into the insulation you use.

I was planning to lay in a barrier also. Currently I have been using pond liner 10-15 ft around the whole house to keep the moisture off. It tough and thick. It can be purchased in just about any length. I would order a piece that would run the whole length. I ordered 150' x 12' for a little over $500 shipped. I can't remember the thickness right now but it would be over kill for the Pex/foam barrier. I would go with something thinner. I went with the thicker stuff because it had like a 10+ year life span with sun exposure.

You can't use the cans of foam in the ground, it will be like a sponge.
Even closed cell foam should have a good thick vapor barrier if in the ground.

The part that I canned foam is not exposed to the ground. Its within a 4" drain tile but good to know. I have used it before indoors but didn't read or examine to see if it is porous or not.

3" PVC is only big enough for two ¾" pex with fairly minimal insulation. With no 90's.
I'd go bigger and keep it straight, with a pull rope.

I was worried about this and did some searching on PEX OD size and realize that 3" is not large enough. At this point I have read enough to plan to run 1.25" but just don't know which product is best. I have seen 1.5 to 1.6" OD on the various products. So 4" would be the minimum size. I have thought of just running a 6". I have also considered running a 6" PVC strait line into the house and just slide a Thermopex like product up in it and not worry about getting the spray foam job done correctly. the older I get the less I worry about cost and focus more on time and aggravation.

Is the pole barn already there now?

Might be time to doo doo or get off the pot, as they almost say, and go all the way & run the whole business now. I would not go less than 1" for a 150' run tho, and 1-1/4" might even be a consideration. It will be pricey no matter if Thermopex or foam in trench (which I think you said were also thinking about?)

LOL! I do need to doo doo or get off the pot. I talked to my spray foam buddy and he had a good suggestion and offer for me. He said to prep the trench and assemble the PVC but don't install to house. He would load it on his truck and spray foam it at his next job. I could then just pick it up and then put it in the ground. Then just slide the PEX in to it at a later date.

Can someone confirm that the OD on 1.25" pex is about 1.5-1.6 inches?

 

[E Yoder]

I'm seeing 1.375" OD.