circulator sizing

STEAM DOCTOR

I have a customer with home 3 stories high(aprox 30 ft high). Home is 34' x 19'. The entire home is served by one forced hot water loop. The supply and return are 1 1/4". There is aprox 125 mbtu going through the loop. What would be an appropriate circulator for this situation? Thank you

STEAM DOCTOR

rad takeoffs

I cant see what is doing with take offs but I am assuming that this is a monoflow system. House is aprox 50 years old.

STEAM DOCTOR

head

How do you figure head when the main is 1 1/4 and the radiator takeoffs are 3/4" or 1". This is a divertor T system.

gennady

circulator

simple sizing is : head=(30+34+19)x2*0.06=9.96 feed of head

on 20F delta t one gallon per minute delivers 10,000 btuhr, 125000/10000= 12.5 gpm



if you take chart on the pump, lets say like this one http://www.taco-hvac.com/uploads/FileLibrary/101-084.pdf and find point corresponding to those numbers, the closest curve to the right will be your pump



you can check this one out http://s3.pexsupply.com/manuals/1350570919940/83616_PROD_FILE.pdf

CMadatMe

Basic Formula Head

Longest run from the outlet of the circulation through the system back to the inlet

Side if the circulator x 1.5 x .04 = head



100' x 1.5 x .04 = 6' head

icesailor

Circulators:

Box of stale donuts says that a 007 would work fine. Or a Wilo Star 21 three speed on #2.

gennady

my box of donuts

my box of donuts after looking at the chart said taco 0014.

007 1t 12.5 gpm will max only 6.5 feet head. unless radiators over sized, and delta T 40F 008 might work.

Just my opinion

gennady

head

Chris , 30+34+19 is max run =85 supply and 85 return, total run 170 feet

CMadatMe

Based On

the limited amount of info the original poster is giving i would agree on the run length.



170 x 1.5 x.04 = 10.2' head



Needs a pump that will do 12.5gpm @11' head. I like to round up.. Grundy 26-99 3-speed would be my choice.

SWEI

load

125,000 BTU/hr actually going through the loop, or going into the gas valve at max firing rate?  Was a heat loss calc done?

Steve Whitbeck

26-99F

I like the Grundfos pumps the best.

BUT - If you are going to use a wet rotor pump make D** sure to put a 100 mesh strainer in front of it on that old system.

gennady

DIRTMAG

for wet rotor pumps we started to offer this http://www.caleffi.us/en_US/Technical_brochures/01137/01137.pdf instead of the regular strainer.

Steve Whitbeck

Dirtmag

That will seperate dirt but stuf can get through it on and if it gets into the wetrotor pump it won't do the pump any good.

gennady

magnet

It has a magnet attached to it, and magnet stops all the magnetic rust particles. Periodically magnet is removed and dirtmag is flushed trough bottom valve. It prevents magnetic rust going to wet rotor and sticking there. Dirtmag is designed with specific purpose to protect wet rotor circulators working in magnetic metal systems

Steve Whitbeck

Wet rotor pumps

I have seen a lot of non magnetic stuff in the impellar of the wet rotor pumps. Throws them off balance and that imbalance tends to destroy the impellar.

gennady

dirtmag

It has a strainer part as well