Circ pump sizing

Cliff Brady

say 6.4 GPM at 20 degree delta-t. Minimum recommended flow rate is 4 GPM. There is flexibility to select the pump you want for the delta-t you design for.

Joh n Brickey

Circ pump sizing

I installed a Munchkin 80M the other day and I used primary/secondary piping. The 80M calls for an 8 gpm circulator pump and I have 3 zones on the system,all radiant floors. 1 zone calls for 5 gpm and the other 2 call for 3 gpm. All the paper work and charts say I can use the Little Red B&G for all the pumps even the primary. Will each pump only pump the gpm it needs in each zone or would I have been better off putting 2 speed pumps in the smaller zones. Maybe I'm making to big a deal about this but any info on other ways to size pumps or options would be great. Thanks, John

S Davis

What is your max head pressure?
I don't use B&G but a Grundfos UP15-42f will pump 11 gpm @ 8' of head, you can use one pump for all three zones and use a differential presure bypass.
You can get rid of two pumps.

S Davis

Dan Peel

High head exchangers

Check your requirements into the primary. Most of the little condensers will require at minimum a 26-64 and many a 26-99 or equal for the primary alone. Size your secondarys on flow requirement, if concerned use a 3spd. Enjoy....Dan

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Joh n Brickey

Thanks for the replies

S. Davis,good idea, I will try the Grundfos pump and zone valves. It will save me some space. Dan Peel, I don't know what you mean by 26-64 or 26-99. Please explain. Thanks!!

Joe Mattiello

Circulator sizing

If you need 8 gpm the 007-F5 will cover your system requirements. To accurately size the circulator, you need to know the load or linear footage of baseboard at 600 BTU per foot, the pipe diameter, and length. With this information, we can calculate the flow rate. Rule of thumb is 1 gpm, per 10,000 btu output.