Circulator Sizing for Indirect
I'm trying to finish specing out the components I'll need to convert my tankless coil to an indirect water heater. At the moment I am trying to properly size the circulator pump. I was hoping someone could check my work. All calculations were taken from the article on circulator sizing on this web site located here: http://www.comfort-calc.net/circulator_sizing.html.
I first calculated Equivelant Feet Pipe as follows: (assuming 1" copper):
16' Copper (est.) x .042 = .672 EFP
1 - Tee (side port) = 4.5 EFP
4 - 90* Elbows = 10 EFP
2 - unions = 1.5 EFP
16.67 EFP x .04 = .67 Feet Head
So assuming a Superstor Ultra SSU45 which has 7.9 Feet Head @ 10gpm (recommended flow rate)
If I assume a 1.5 Feet Head for the boiler that would be:
Boiler = 1.5
Plumbing = .67
SSU45 = 7.9
10.07 Total Feet Head @ 10gpm
If this is correct then using the the Taco Pump curves as shown here http://www.comfort-calc.net/Piping/Taco_pump_curves.JPG in order to maintain the Superstor's 10gpm recommended flow rate I would need at
least Taco 0012 assuming it is better to have a little more flow rather than less then spec as indicated on Taco's own web site here: http://www.taco-hvac.com/uploads/Fil...ves003-008.pdf and here: http://www.taco-hvac.com/uploads/Fil...es009-0014.pdf
Thanks in advance for any additional insights/help/guidance you'd be willing to share.
take a look at Grundfos 15-58
If you are trying to span between a taco 007 and 010 take a look at the small Grundfos three speed. At 10 feet of head you can get 6 gpm on medium and 10 gpm on high with a 15-58.
You will have some adjustment possibilities to tune the delta T across the boiler if the equivalent feet of pipe calculation is not exactly matching the real system.