Not Burying PEX

[DMX_512]

I am now thinking that having my EKO 40 outside might be better for us.
I can build a shed on or just outside of the walk-out basement patio. the EKO will be less that 20 feet from the house.
My question is this. If I use 1 1/4 insulated PEX unburied (the entire run will be on top of concrete patio) am I asking for trouble?
What is a good source for insulated 1 1/4 inch pex?

Thanks

 

[Eric Johnson]

I run two pex-al-pex lines through my greenhouse, which is not heated in the winter. I put cheap foam insulation around the individual pipes (1" supply and return and 3/4" supply & return), then wrap the whole works in fiberglass bat insulation, encase the whole assembly in wire screen to keep the mice out, then wrap everything in plastic. It runs through a wood-frame enclosure. Works fine. There are plenty of potential variations and upgrades to that approach, such as enclosing the insulated pipe in a box made out of 2" foam board, etc.

At minimum, make sure your shed has a concrete floor. If you build it out of cinderblocks, you don't have to worry about clearances. I have about an inch of clearance on the left and right sides of my boiler. The only drawback is maintenance. I'll have to pull it out of there if I ever need to get the side panels off.

 

[Paso]

I have a run that is 10 ft long, of 1 1/4 that is running about waist high from my trailer to building. ( OWB inside trailer)

I have it wrapped in reflectex air pocketed aluminum foil that also is wrapped in regular batt insulation and the snow sits on top un melted.

I find very little temp drop in that 10 ft if any.

 

[DMX_512]

Eric,
Yeah i was thinking that "fabricated" might work just as well.
In your opinion would pex be better than black pipe?

Thanks
Ben

 

[Eric Johnson]

Pex is a lot easier to work with, and probably cheaper, but black iron would work, too. The nice thing about the iron is that if you overheat your boiler and try to pump 250+ water through pex, it could melt.

 

[DMX_512]

I guess copper would be about the easiest. The rest of the system will be copper.

What precautions against freezing? UPS/marine batt's? Primary pump running 24/7?

Thanks,
Ben

 

[Eric Johnson]

The more insulation the better. One freeze protection scheme would involve running a pump off a strap-on aquastat set to make the connection at 40 degrees. You could also put heat tape in your pipe assembly, I believe. If you do it right, you should be able to isolate and drain the vulnerable section of piping in the event of an extended power outage. Or blow it out with compressed air, assuming you have a tank charged up before the power fails.

 

[DMX_512]

I am thinking of putting this on an existing 6 inch concrete slab (walkout patio).
Anyone, with more construction / structural experience than I have any thoughts?
The design and construction of the shed itself is no problem. Just wondering about the existing slab being up to the task.

 

[Chris S]

The slab will support your boiler no problem (imo).
Pex gets vey pliable when heated, if thats a concern, and while pex is inexpensive, it depends on how much you have to buy.

If you could make the run with straight lengths of black pipe, that would also be fairly easy for that part.
I ran insulated pex through 6" drainage pipe- keeps the insulation dry etc. and fairly inexpensive (SDR35)

The shed we built for an eko 40 measures 7'x10', allows for proper clearances, and a little bit of room inside for other stuff, not really wood storage though.
I'll post some pice shortly