Pipe size for forced hot water

Eric L._2

So 1/2 inch is good for 15000 btu of fin tube? What if you have a 60 EDR CI radiator(10200 btu @ 180deg)? Thanks

Eric L._2

Pipe size for forced hot water?

Just trying to educate myself gentlemen. On Burnham's site they list supply pipe connections for forced hot water as:

HOT WATER - Two-Pipe Forced Circulation

Up to 100 sq. ft. . . . . . . . . . . 1/2 inch

101 sq. ft. and larger . . . . . . . .3/4 inch

Does this refer to radiation on each run from the main or to total radiation for the whole system? Thanks

kpc_12

generally speaking...

1/2" --25' 600btu/ ft. copper fin tube baseboard or 15K btu
3/4" 67' basebd or 40K btu
baseed on a 20 deg. temp. drop from when you start to return and a avg water temp of 180F...you can play w/ these numbers if you know what you are doing but these will work.kpc

Eric L._2

Pipe size for forced hot water

Anybody?

ALH_4

Pipe Sizing

Pipe sizing depends on several things: heat load, delta-T, fluid temp, and design temp. I recommend investing in Siggy's Hydronic Design Studio.

kpc_14

btu's are....

btu's....

heatguy

pipe size

here are some rules of thumb 20,000=1/2 40,000=3/4 90,000=1" thats at apox 3gpm.you take the radiations output at design temp and do the math as to how many ft of baseboard or radiation you can install with whichever pipe size will work

tomd7735

Grundfos

is giving away a free booklet on their sire about hydronics. It gives all the formulas to figure this out.

Eric L._2

pipe size

Forgive me if I'm being dense but I still don't understand something. If 1/2 will carry 20000 , does that mean it will carry 20,000 to one radiator only on a home run type setup or is it 20K to each radiator. My heat loss is 88K divided up among 15 oversized CI rads. Thanks for your patience.

Eric L.

[Deleted User]

maybe this will help

Following the rules of thumb already passed on - 1/2" will only carry the approx. 20,000 btu at any one point. If ALL the water passing through a single point of 1/2" is only expected to deliver the approx 20,000 btu then you're all set. IT doesn't matter if the 20kBTU are going to 1000 20BTU radiators or a single 20,000BTU radiator (piping configurations and head loss not taken into account). Add up all the btus you expect to jam through that single point of 1/2" pipe - if it is 20k or less you can throetically do it....

Actually you can do it even if it all adds up to 60kBTU - but it won't heat the radiator!

Eric L._3

Pipe size for forced hot water

So if I was to run two 8 Loop Manifolds each fed through lets say a 1 inch line , I can feed 20k to each loop on the manifold, assuming of course the boiler can supply that many btu's?

Eric L._2

TTT