'One Pipe System'

Mike Z.

I currently have a One Pipe Hot Water Boiler System Installed in my house. The Main Trunk line is 1 1/4" with 1 1/4 x 3/4 Diverter tees installed wherever the is a Radiator. The supply side is a normal tee and the return side is the diverter tee. My question is "Is this System Worth Saving?" Is it worth it to heat all of the extra water in the 1 1/4" main? The main loops around the entire perimeter of the house and all radiators are above the main. I only discovered my type of system because i am going to add heat to 2 additional rooms that were added on to the house and when i seen the way the plumbing was piped i was confused at first, but now after reading this http://www.heatinghelp.com/heating_howcome3.cfm it all makes sense, but is it efficient? I also installed a new boiler last winter with an indirect fired hot water tank with its zone having priority and its own circulator. The main loop also has its own circulator(Obvious) but now im thinking it may be undersized because of the diverter tee's restricting the flow in the pipe. I'm sure you get where im trying to go with this or at least its enough information to get started with, So i await the Professionals Opinion!
Thanks In Advance!!!
-Mike

brucewo1b

Mike

First if its heating fine then you in good shape, second diverter tee systems deliver better hot water to all radiators more equilly, now if you were to pipe it series then the first radiator would be hot the last might not get enough hot water to do the job right. smaller zones work in series but temp drops as you go, so the larger the zone the bigger the need for monoflow type systems or home run type systems, it all in how it was designed.

Perry_2

Worth saving

That is an excellent system - and paired with the right modern boiler can deliver very good heat and low fuel bills. It is the system I have in my house and is called a Monoflow T system.

Unfortuantely many heating people today do not really understand how it works and how to modify it. If you find someone who does you may be able to add your expansion rooms to the monoflow T system.

If not - don't tamper with it, and you can add a new zone back at the boiler for equivelent radiators (if you have cast iron radiators - you expansion needs cast iron radiators) or underfloor radiant heating.

Be sure to do a heat loss calc on the house and see if the boiler can handle additional rooms; which should not be a problem for an older boiler as they were ususally well oversized.

Perry