Circulator: System Head Vs GPM Spreadsheet W/Graphed Output

The spreadsheet is attached. Enter data on sheet 1 (User data input is the blue background stuff). See graphical output on sheet 2.

If you do not like the graphs output range (span) for GPM and/or Head, change the span on sheet 1 by either reducing the initial GPM of Flow or increasing it. Initially it is set to begin at 1.0 GPM. Try 0.5, 1.0, 1.5, 2.0, etc... until you find a span of GPM and Head that suit your needs. Lowest initial GPM selection is 0.5. Use increments of 0.5.

Overlay the graphical output of this spreadsheet onto your circulators pump curve chart, and where the two charts lines intersect, that will be your actual GPM of flow, and actual system head for said GPM flow.

Kick the spreadsheets tires and let me know your thoughts. Hope it works well in Excel, as it was build using OpenOffice on Linux (UNIX). Let me know.

I'm curious. Does it work in Excel?

I will try it later in Excel.

Seems to work fine.

How does the friction change if the system is open rather than closed?

Rob R. wrote:Seems to work fine.

How does the friction change if the system is open rather than closed?

Do you you mean as for a steam or wood boiler system? This should have no impact that I can fathom vs. a closed/pressurized hot water system.

I didn't think so either, but you specifically said "closed loop" in one of the cells so I thought I would ask.

Rob R. wrote:I didn't think so either, but you specifically said "closed loop" in one of the cells so I thought I would ask.

Oops, my mistake. Closed/pressurized is the only type I think abut due to my system being of that type.

But it changes nothing. Just unprotect, change the text, re-protect, and save. Fixed.

Rob R. wrote:I didn't think so either, but you specifically said "closed loop" in one of the cells so I thought I would ask.

What I meant by this is that as long as the water loops back to its point of origin there is no height induced head, and only friction induced head. My spreadsheet attempts to calculate only friction induced head.

To show the output in a real world application, I used my own 4 zones and single circulator with zone valves system. If I did not have my DPBV loop open, the attached is how my system would perform by zone. I apologize in advance for getting sloppier with each respective opened zone in both plotting my points, and in drawing my "system curve" lines. Actual real world system flow in GPM is where my programs output (the blue lines) intersect the circulators pump curve for each of its 3 speeds, and with respect to how many zone valves are open at one time.

Note for those interested: The Taco OOR 3-Speed circulator is no longer made. Vanished about 6 years ago.

Not that its relevant to this thread, but I believe my total GPM flow through my various zones with the DPBV (differential pressure bypass valve) loop wide open are modified as follows for my circulator set to "LOW" speed:

1 Zone open = 2.55 GPM
2 Zones open = 4.8 GPM
3 Zones open = 6.7 GPM
4 Zones open = 8.65 GPM

I think all these "tools" Larry makes (along with any other ones) need to be put into a permanent place in the knowledge database, or at least a separate forum heading titled Tools so the can be quickly accessed.