Combining pipes to minimize runs on new hydronic system

jeremypbeasley

Building my first hydronic system as a homeowner. 15 original Rocco radiators, all new 1/2" hePEX home runs to 1" Uponor manifolds.

My space is extremely limited and I have to put one manifold near the boiler and the other two about 12' away. In order to limit the amount of steel pipe I need to run, I want to minimize the amount of steel pipe I'm running.

I have two options:

A ) Pumps close to the boiler, 3 individual pipes running the hot lines, combined cold lines

B ) Far less pipe, pumps closer to the individual manifolds, combined lines for hot and cold

Of these two options, which is more ideal and why?

It's nice to have all the pumps and wiring confined to one space, but it's a lot more challenging to make that space work, especially for a very novice plumber.

I'd greatly appreciate any other off-topic criticism of my diagram and plans.

Thanks for your time.

Jamie Hall

Either one will work fine. It's more a matter of convenience, really. There is something to be said for having evrything in more or less one place, but ... really, I'd say take your pick. Do watch your pipe sizes and velocities, though -- you may need a bigger pipe for the longer run option.

jeremypbeasley

Jamie Hall said:

Either one will work fine. It's more a matter of convenience, really. There is something to be said for having evrything in more or less one place, but ... really, I'd say take your pick. Do watch your pipe sizes and velocities, though -- you may need a bigger pipe for the longer run option.

Thanks a ton! Any tips on how I go about determining pipe size? I assume it starts with a GPM calc, but beyond know the GPM demand, I'm not clear on how to move forward. What's coming out of the boiler itself is only 1.25" so I assume going any larger would be pointless.

Rich_49

How many rads on each manifold ? You could quite probably use 1 manifold with actuators and run 1/2 homeruns to each rad . How many zones are you planning on having ? 1 1/4" would be sufficient .

You should call or contact Rococo and have them verify weather the rated outputs are based on a 50* Delta between water temp and room temp or water temp drop while in the radiator . 1 circulator will almost certainly be large enough because your head will be very low .

hot_rod

You should really have a room by room load calc to see what output you need from each of those radiators. Then you work the tube sizing and circ selection from there

Could be some rooms need 8000 btu/ hr, some may only need 1000

If they are all getting the same temperature one circ could possibly supply all three remote manifolds.

Teemok

Option A. How many GPM the manifolds need will determine pipe size. Go with bigger pipe vs a bigger pump generally. Your boiler has a minimum flow rate and if it's cast iron or fin tube it may need minimum return temperature protection. The radiators flow needs may not match the boilers needs. Water temperature and flow numbers and boiler type and size choice please?