[an error occurred while processing this directive]
Posted by HeatPro on September 02, 2008 at 10:26:39:
In Reply to: Re: larger to smaller pipes posted by jeremiah on September 01, 2008 at 20:59:45:
That's true of a Taco 007 pump through a maximum longest circuit length of 150 feet from pump back to pump through the combined circuit.
Actually, if each of the two circuits have a 'real' combination of branches that sum to the equivalent of a 1-1/4 circuit pipe, much more than that can be pumped; you just need to know how much radiation there is to pump for.
As you have two circuits larger than 3/4, you can pump at least twice the amount at 150 feet maximum circuit length, or 8 gpm, provided the pump can handle it, as the two circuits split the flow to about half in each one. The 3/4 stubs at the boiler would make the water increase velocity, possible making wear over time at that point. The question would be why there is a 3/4 stub on the boiler. More likely, more water than 40,000 btuh isn't required as the boiler input is about 50,000 btuh.
Sizing pipe circuits is an interesting pastime.