New HVAC install

[VAWellDriller]

I posted this in the HVAC forum as well, but here it is again, in case you plumbers don't look at that.

I am building a new house and am installing an open loop geo HVAC system, and have a supply and return well. The HVAC contractor normally does closed loop systems, and has that sub install all the plumbing right up to the units inside. I'm really not sure why, but he doesn't want to do any plumbing, and wants me to handle the water connections to the unit. I'm a well driller by trade, so a little plumbing doesn't scare me, just wondering if there is a preferred material to use, and why? I'm not very good with copper, and I have CPVC plumbing for the rest of the house. I was just going to continue with the CPVC for the HVAC unless there is something I'm missing. The water temp (entering and leaving) should never be out of the 45 - 75 degree F range I don't think.

 

[Texas Wellman]

I'm not a plumber but I'm told that by code PVC is not allowed indoors. Of course, CPVC is. I have some family in the plumbing trades and they all use PEX now.

I have used CPVC a lot for house projects and I find it to be a very good material and easy to work with.
What size are the taps for the HVAC and will you run PVC up to the house and then convert to CPVC? How much water does it use?

 

[Sponsor]

 

[Craigpump]

I wouldn't do it, but I've seen pvc used in geo installs.

 

[VAWellDriller]

I know PVC is allowed inside...we use it all the time for water treatment, sometimes incoming water lines, and of course, all DWV pipe is PVC. I have 1.25" poly coming in the basement for supply and return, (2) 3 ton units, hearing lots of different stories about how much water they really need, but the high end is 3 gpm / ton, so I am starting with that...each unit will get a 9 gpm flow to start. I may run that down some, because the other 50% of people around here say I only need 1.5 gpm / ton; I will have throttling valves and temp gauges so I can see what it really needs when we start it. Its a real short run in the house, will have 1" off the tank tee and 3/4" run for about 4 ft to each unit. My domestic supply is off a different well.

Craig: any particular reason you say not to use CPVC. I like PVC as well, no problems...the only reason I like CPVC is you can get the nice brass thread adapters; and I was thinking if anything ever did go wrong and the water got overheated, the brass thread adapters and the CPVC would handle the heat better.

 

[Texas Wellman]

CPVC is supposed to be pretty stout for high temp water. I do not remember what the last piece said on the side as far as temp and pressure but it was up there.

I use PVC all the time indoors. It's great for cold water on softeners. Of course DWV pipe is PVC and that is allowed under code.

 

[Texas Wellman]

BTW my friend is putting in an open geo this year so please keep us updated on this thread. Of course, our water here is about 70° year round and we are mostly about the cooling side of the equation rather than the heating.

 

[Craigpump]

I think you miss understood, I don't have anything against CPVC, but I do remember reading that pvc inside the house isn't the way to go.