Did the math pump sizing

[mtr7982]

Hello,

New here, but, have been reading for a while now.

So I did the math and need a little help on pump sizing planned on Taco pumps but, I'm always open to better suggestions.

I have 5.25 gpm @36' of head on one zone


I have three (3) other zones 3 gpm @30' of head

I look at the Taco sizing chart and I'm seeing the 009 as being the closest , the 0011 and 0013 match the head but, have higher gpm. I don't know if the higher gpm is better or not...???

I'm new to this hydronic heating thing and I've already been raked over the coals to the tune of 2k for a supposed great design!
THANKS

 

[Bob Rohr]

That seems like a fairly high head number? What type of heat emitters are you circulating through? Or are they long small radiant loops?t

 

[jebatty]

I see the 009 as producing 0 flow at 36 feet of head. It may work on the 3 gpm at 30 feet of head, but you are not in a desirable area of the pump curve. What are the details on your system that results in such high pump head?

 

[heaterman]

Ditto to what Jim and Bob said. What are the tubing/piping details in that zone with 36' head? If that is on an open/unpressurized system you will never have good service from any pump. When you get that high you simply must have some positive pressure at the impellor inlet or it will cavitate and destroy itself.
So
A: Let's see if you really have that much resistance to flow in that zone. and.....
B: Let's see if anything can be done to get it down to reasonable levels. (<15' head)

 

[Coal Reaper]

Sum ting wong

 

[duramaxman05]

I have a grndfos 26-99. 34gpm and up to 31ft head. It is also a 3 speed.

 

[maple1]

I have a grndfos 26-99. 34gpm and up to 31ft head. It is also a 3 speed.

That pump won't flow any water at 30 feet of head though. At least that's what its pump curve shows.

 

[mtr7982]

I may have done something wrong in my calculations then, I've been a builder for 20 years but barely get by as far as plumbing goes, not many with radiant experience around here.

Zone 1 (7) 300' loops of 1/2" Pex 5 gpm
Zone 2, (4) 256' loops of 1/2" Pex 3 gpm
Zone 3, (4) 256' loops of 1/2" Pex 3 gpm
Zone 4, (4) 256' loops of 1/2" Pex 3 gpm

2,3,4 are two runs in each joist bay, 1 is the basement slab.

THANKS SO MUCH

 

[heaterman]

Given that you are handicapped right from the start with that length of 1" tube, you should pipe the 1" into the house as a primary loop and go right back out to the boiler rather than trying to put everything in a series like CB's diagram shows.

Take all your heating loads off that loop individually as secondary loops with their own pumps or a single pump and zone valves to each zone.
If everything is as you describe your system would be in hydronic never never land if it was piped in series. Not going to happen.