Multilpe Boilers

RobG

On a multiple boiler install, with pumps on each boiler, does it need to be piped in reverse return?



Rob

Unknown

ya asking this

Ya asking this after you make comment about my expertise on other post, that's explained how much you don't know ..

Unknown

ya asking this

Ya asking this after you make comment about my expertise on other post, that's explained how much you don't know ..

SWEI

As usual

it depends.  Reverse return is best, but a big header pipe with short branches is pretty forgiving.  The important thing in my mind is hydraulic separation.

RobG

rjb

Please use correct grammar. (And only hit the "submit post" button once). I noticed that YOU didn't answer my question, only criticised as usual.

Unknown

i do have grammer

I do have grammer problem due to my disabilty, you have a problem with that??

RobG

multiple boilers

What would be the best way to balance a system with two different sized boilers requiring two different flow rates? Two primary loops with correctly sized pumps and a staged controller to fire the smaller boiler until its capacity exceeds the load, then fire the larger boiler and shut down the smaller until its unable to meet the load, then fire both? The multiple / modular systems I am used to utilize the same size boilers.

And rjb, what is your disability? Anger management? 



Rob

Mark Eatherton

Either Primary secondary or...

either direct or reverse return, and as others have said, make certain the headers are short and fat.



If you go parallel reverse ir direct return, you MUST have a check valve on each individual boiler pump.



If more than 2 units, and one common pump then I usually go reverse return. It is somewhat self balancing if the pressure drops though the units are the same.. If each unit has its own pump and check, and the headers are correctly sized, it shouldn't make that big of a difference if its direct or reverse return.



ME



Edited: Changed should to shouldn't. Thanks for the catch Kurt.



ME

JStar

RJB

Violation of Rule #1. Please stop or avoid posting.

Steve Whitbeck

piping

What I do is have one set of closely spaced tee's ( primary / secondary piping )

but I use the same size branch as the main ( OR big enough to handle the total flow of all boilers ) 

I then tee off to each boiler. All returns to boilers come off of one branch and all supplies from boilers come off of the other branch.

Each boiler has it's own pump and piping that should be sized for that boiler.

This way if the boilers are staged in it won't matter what one is fired first if you have them rotate the lead boiler.

DanHolohan

I have to agree.

He's making a good point, Ray. We have a good thing here. Please be nice.