clueless but trying to learn

sgall

I am having an Alpine 80 installed soon and I am trying to make sure it goes well.  In the B&G guide Zoning Made Easy it mentions that in a 3 zone system any shared piping must be big enough to accomodate the shared flow.  The current piping for each zone is 1 1/4" and it is a monoflow system. What is confusing is that the boiler tappings are only 1".  Should my plumber do what the B&G guide says or are is your flow already restricted by the 1" boiler tapping size.  Thank you.

Mark Eatherton

Tapping size be damned...

Most European boilers come with smaller tappings because they are assuming a different design temperature differential of the flow. THey use 30 degrees C, we use 20 degrees F.



Size your distribution piping system for a 20 degree F delta T, then size the boiler interface piping for a 30 degree F differential and it should get you fairly close.



ME

sgall

Thank you Mark

for your reply.  The attached diagram is what the system will look like except I will have 3 zones instead of 2 as pictured.  I don't know if it was clear but this boiler is a replacement.  Just to make sure I am understanding you then it is okay to make the piping circled in black 1 1/2" while the system piping, boiler piping and IHW piping is all 1"?  Thanks again.