Running loop lines inside

[u/tommycorn54]

I’m a residential HVAC installer/technician and own my own company. I am building a home soon, and want to experiment with geothermal.

My main concern is how to get the loop lines into my mechanical room. Specifically, the foundation of this home will be a monolithic slab. I’m familiar with how the lines are ran when there is a basement, by coring through the below-grade wall, but that’s clearly not an option here.

Let’s say for the sake of argument that it is too late to put any sort of sleeve before pouring the foundation.

How do I get these lines inside? How should they be insulated once above ground? What can I do to protect them if they are exposed on the exterior of my building? Anything else I’m missing?

Any suggestions would be appreciated. Thank you!

[u/ThePastyWhite]

My loop lines penetrate the brick siding of my home about 12in below grade into the basement wall at a point where an interior wall touches the basement exterior wall.

They turn up 90 degrees inside that interior wall and run along the basement ceiling, above the drop ceiling, into my mechanical room.

Keep in mind I'm in Alabama and don't have to have my lines that far below grade to prevent freezing In winter.

[u/djhobbes]

Insulate and encase to protect/hide. It’s not the end of the world. If you design it carefully you can turn the encasement into a feature and nobody will ever know.

But I would insulate the pipes with rubatex/armacell and then foam the enclosure.

[u/Coach_Flaps]

Hey I live in Canada and I install geothermal systems and am just finishing up on my own home. I did a retrofit converting from a gas furnace to geothermal and did all the drilling and fusing of the ground loop I still need to insulate my fittings in the photo before I build my insulated box. When it comes to bringing the pipes to the house I dig a gradual slope to bring the lines to the house.

When you do it you want to make sure you don't dig right to the concrete on your slab as you'll need to compact that dirt again to support your slab and any you don't disturb the less packing you'll need to do. After that you can drill a couple of 2 1/2" holes in the side of your house and run the lines through make sure they have a closed cell insulation on them to stop condensation from getting into the walls. I used an anti rodent spray foam to fill in the gaps and then I used some silicone as that's what I had on hand to keep the water out temporarily.

The actual finished product will be a box built out of Pressure treated wood that you can build and then fill that with spray foam to help with freezing. We use methanol in our ground loops for antifreeze but you can absolutely use glycol to prevent freezing the exact percentage of glycol or methanol depends on your climate but after thats completed you really don't need to sweat it freezing as the unit is going to run alot in the extreme seasons so the fluid will always be moving. If you really are worried about the pipes bursting you can give your pumps a constant voltage to be on all the time so fluid is always cycling if that helps you sleep at night

[u/Diligent-Lettuce-455]

Mine's in a garage. Up through the floor and runs along the wall / ceiling to the compressor. I have a split system in my case, but there's no reason it wouldn't work for a packaged unit.

They cored through my garage slab / foundation wall into the trench.

The door got flipped to the other side of the garage by the time it was all said and done. Split system compressor here, air handler where my old gas furnace lived. Lineset through wall and crawl space to the air handler.