Questions about Split Loop type system with HWBB

hot_rod

You could series the manifolds, looks like you only have 5 runs, 3 in one 2 on the other?

newtonkid88

hot_rod said:

You could series the manifolds, looks like you only have 5 runs, 3 in one 2 on the other?

6 runs. It would either be 4 and 2 or 3 and 3.

With a single manifold, my two longest 1/2” loops would be 85’ and 99’. About $655 for pipe.

With 2 manifolds in series, the two longest 1/2” runs would be 67’ and 78’. Total pipe and manifold only cost would be $860

With a reverse-return, the two longest 1/2” (or 3/4”?) runs would be 50’ and 53’. Total pipe cost $960 for the 1/2” branches and 1” main. Or $1,120 for 3/4” branches and 1” main.

With the way my existing domestic plumbing and electrical and framing is in the real world, I believe both manifold options would leave my basement looking like spaghetti, not that it really matters for an unfinished basement. 

hot_rod

Yes, it does end up being a lot of tube at the manifold, it can be neatly done with some planning. You have a number of ways to do this, all will work and heat just fine
For the pro it comes down to personal preference or favorite method.

hot_rod

Here is. 100 ft loop of 1/2 Pex at 1.5 gpm, about 15,000 btu/hr at 20 degree delta

plasticpioe.org

newtonkid88

hot_rod said:

Yes, it does end up being a lot of tube at the manifold, it can be neatly done with some planning. You have a number of ways to do this, all will work and heat just fine
For the pro it comes down to personal preference or favorite method.

Thank you so much for your help Hot Rod and everybody else.

I've decided to do a homerun for both floors. For the 2nd floor, two manifolds in series to eliminate spaghetti in the crawl space opening, especially for future runs in the addition. It's going to cost me more but might as well do it "right".

Gonna run 1" hePex to the boiler and 1/2" hePex to the baseboard elements. Gonna solder my own manifolds.

If a supply branch comes from the supply manifold closest to the boiler, does the return branch have to go back to the return manifold near the boiler? Or can it come back to the addition's manifold?