circ. confusion

Rich Corcoran_29

Hi Joe,

I have to question your statement about the performance of a 007 @ 1.5 gpm. If I look at you published curve, it looks to me like a 007 will generate about 10' of head.

I'm not trying to throw stones or anything - I think you do a great job supporting the discussions on the Wall. I'm just having a hard time understanding how your statement can be correct.

RC

Johnny11

size circ to choose

I am attempting to size a circ. for a closed, single loop, b/b hydronic system. It's a small zone; 15,000Btu/Hr demand, 120 ft 3/4" pipe. I calculated total head loss about 10FT. I understand it's best to keep flow rate less than 4GPM. I have also learned in school it's best to select a pump for use in the middle third of it's performance curve. When I compare the Taco "00" performance curves to my needs I'm way at the top of the curve. Am I looking at the wrong pump series?

Rich Corcoran_28

Circ. selection

Johnny,

I've attached a pdf of the UPS 15-58FC pump. I plotted your stated duty point (4 gpm @ 10'). You may want to revisit your calculations - 4 gpm is a lot of flow for a small load. You'll end up with a very narrow delta T and higher friction loss.

A BB loop is typically designed around a delta T of 20 degrees, 1.5 gpm for 15K btu's. 125' of 3/4" copper shouldn't have 10' of loss, unless there's a whole lot going on in the piping network.
Check out speed 1 on this pump, it's all you need (and a more!)

RC

Johnny11

Thanks RC
Speed 1 will work well.

I was aiming for a Q<<4.0 GPM (as you said 1.5 to 2 GPM max) and that was the source of my confusion: the Taco "00" curves I have offered very little in the 0<Q<5 GPM range.


Thanks again

Rich Corcoran_28

Circ selection

Johnny,

Glad to help. Merry Christmas!

RC

Joe Mattiello_2

007-F5 will deliver 1.5gpm @ 2.5 Ft Hd

Johnny
I was reading your thread and wondering how you came up with the 4 gpm originally. The load dictates the flow, and the flow will dictate the pipe size and the head the pump needs to overcome to deliver the required flow to satisfy the load. Assuming a 20delta T, you can divide the load by 10,000 to give you 1.5 gpm required. The head is 1.5 gpm through 120’ X 1.5 of ¾” piping, approximately 2.5ft. The 007 will deliver 1.5 gpm @ 2.5 ft hd, and do a nice job for you. The system curve will correct the pump without over pressuring the system, because of the 007’s relatively flat curve.

Joe Mattiello
Technical Support Technician
Tel. 401-942-8000 X 484
Fax. 401-942-2360
joemat@taco-hvac.com

Joe Mattiello_2

007-F5 circulator

Ideally, a circulator would produce the exact flow rate required, while operating at it’s best efficiency point, using little electrical power, be very inexpensive, and be available at most retail outlets for quick availability. The 007-F5 covers most of those requirements. Admittedly, the 007 does produce more head then required, and a 003 pump would be a better candidate for this application, but the 003 is bronze, more expensive, and not readily available on a Sunday afternoon when the system pump fails. My message is if you look at the whole picture the 007 will do a nice job over all.