Barndominium/Shop or "real" House?

[WinterDeere]

Can you valve off the stairwell for future use/non-use? Now's the time to install it. You'll have a tough time going back.

Agreed. PEX is cheap, install it now, as a separate loop. No one says you need to connect it, just install it.

 

[ETD66SS]

Any AC experts/installers?

One other thing before the concret pour.

I want to have central air in the living space.

Should I put in some conduit sweeps that go under the skirt board and up through the slab into the wall for the AC condenser power and refrigerant lines? Or would these just go through the wall above grade?

I'm thinking they would need to go above grade so there is no water sitting in the conduit.

 

[LittleBittyBigJohn]

They run through the wall on the house I just had built. But my AC units are in the attic, which could be less than ideal according to who you talk to.

 

[Carl_NH]

Agree with you LBBJ - thru the wall for the line sets and usually a electrical disconnect box next to the compressor. As far as the air handlers, many are put in attics, and these can be problematic if the drain pan leaks or drain hole is plugged. If possible put the air handler/heat exchanger in the basement or ground floor with a drain

 

[EddieWalker]

When I built my house, I ran two-inch conduit from the mechanical room to the side of my house where the outside unit will be. At the time, I thought it would be better than running the lines through the attic space.
It worked fine, but when we had the unit replaced, the went up through the attic for the new lines and there never was an advantage to having the lines under the slab.

 

[WinterDeere]

I've always seen refrigerant lines punched thru the wall a foot or two above grade, never below. Even on new construction.

I'd suspect the losses of having them below grade, whether direct burial or in conduit that's almost certain to end up wet, runs any other advantage of trying to put them below grade.

Look at all the issues the outside wood boiler guys have with running their line sets below grade. They show it can be done, but it's certainly not the easy or efficient way to get three feet of exposed line from outside to inside.

 

[ETD66SS]

I'm ready to start running my pex:

Used one of those foam heat knives to take off some nubs where the manifold will be located.

 

[EddieWalker]

Do you weave the PEX through the bumps on the foam?

 

[ETD66SS]

Do you weave the PEX through the bumps on the foam?

Most of the videos I watched guys were stepping on the pex to force between the nubs. At first I did this but it was causing the edges of the styrofoam to break off. I soon found a method which worked way better. I would keep an arc in the pex so it generated downward pressure via a spring force while very slightly weaving the tube back and forth. You only have to move about 1/8 inch back and forth.

This worked much better. It simultaneously fully seated the pex and there was no damage to the foam. Also no need to go back over to make sure the pex is fully seated.

One bad thing about this methid is you have to be closer to the foam so have to bend over quite far. After each loop my lower back was on fire.

 

[Carl_NH]

Looks really good - nice, clean installation!