Sizing Pipe for Primary Loop?

GrassHopper

Just getting started in the heating business and trying to find out how to size the piping around the boiler.

Is there a rule of thumb or formula guys use?

Found a bit of info on the net for copper pipe.

3/4" can handle 5gpm and 50,000 Btus

1" -  10gpm & 10,000 Btus

1-1/4" - 18gpm & 18,000 Btus

What about steel pipe?

Ex. Boiler output required 51430 btu/h

total flow rate: 5.69 gpm

max head loss 5.19 ft

what size piping would I need?

Thanks 

CMadatMe

Flowrates

GPM Flow Rate = 8.33 x 60 x Delta-T divided by BTU output. In your example the flow rate would be 5.1GPM utilizing the standard 20 degree delta-t. You would need 1" pipe not 3/4". Max GPM for 3/4" is 4GPM or 40,000 btus on a 20 degree delta-t or if I was running a 30 degree delta-t then I could pull out 60,000 btus at 4gpm.

EricAune

Check out the Shop page on this site

If you are looking for info you can use right now and at a low price buy Dan's book -



"Hydronic Radiant Heating - A Practical Guide for the Nonengineer Installer"You wont be sorry! 



If you are looking for a text book style of learning you could also buy from this site -



Modern Hydronic Heating (Second Edition)

by John Siegenthaler



If you want to do it right you will need to put forth some effort and study from two of the best we have!

GrassHopper

Thanks Guys

Thanks guys,

I will be definitely getting those books for sure.  Hopefully the heating business will treat me good.

Thanks again,

Kevin

Halifax, Nova Scotia

EricAune

Good Luck!

I hope you do well.  I think all would say that, you have found a real data base of knowledge and insight into the world of hydronics.  I think I speak for all, welcome.