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1/2\" upnor wirsbo he pex installation???

Garett_2 Member Posts: 3
I'm installing a hydronic heating system throughout a home that is 3 storey and using 1/2" wirsbo he pex tubing. Currently there is 12 rads with possible 4 more to be added. I've run a dedicated line to each rad I'm now worried about that I might not have enough flow especially with the rads that are further away from the boiler. Tried to use as few elbows and couplings where possible, but sometimes couldn't help it as the he pex bends but only so much before you kink it. Is there anything I could do, perhaps using a stronger pump? to ensure proper flow. How do I know what size pump to use, would it help to have two pumps one for feed and one for return??

any suggestion would be much appreciated

by the way 7/8" would have been practically impossible to use and bend and I had to go through floors, joinst studs to get them throughout the house.

Is there a trick to building the manifold to ensure the best flow??


  • you can quite easily push 10k to 15kBTUs/hr through a radiator at 1 GPM if you design for a 20 degree or 30 degree drop across the radiator.

    It's pretty unusual to need anything close to that out of a single radiator, though as always the answer, my friend, is all in the heat load calculation.

    use a manifold with flow meters and balancing valves. Even better, add some TRVs to the radiators.
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