Pipe Sizing

Brad White_103

You got it, Todd-

If you have a given flow rate the only variable you can work with is the temperature drop.

Take your 50 GPM for example. Yes, you can get 500 MBH out of it at a 20 degreee delta-T, but a million if a 40 degree delta-T, two-million if an 80-degree delta-T.

The best use of high delta-T's is with injection systems where the secondary circuit has much lower temperatures. A little 180 F. water can make a lot of 100 F water for a radiant floor as one example.

The effect of course is diminished when you need higher average water temperatures such as a fan coil system.

You got it.

Todd Schliphack

Pipe Size for HW Boilers

I am trying to confirm the max BTU's I can flow through a black pipe. What we have is a fhw system with several 2" black drops from a 6" main. According to "pumping away" we can flow 50gpm through 2"iron pipe. If we need to get more BTUs through the 2" drops is that simply a function of a differant delta T??? or is 50gpm good for 500mbh and that's it??

Todd Schliphack

Thanks Brad