A heating contractor, who’s tired
of coaxing 500-pound cast-iron boilers into homes, decides to try out a
wall-mounted mod/con boiler because of its light weight and side wall venting.
An
installer is advised to use a buffer tank to prevent short cycling of a low
mass boiler serving several independently controlled space heating zones ...
The
installer got a great price on a “contractor pack” of 3/4-inch copper tees, so
the supply and return manifolds are built with 3/4-inch copper, as are all the
zone circuits ...
As it exists, this system works relatively well, but it could be further refined. See if you can spot some design details that would provide equal or better performance while using less hardware.
Overview: An installer has decided to use a mod/con boiler with a high head loss characteristic and connects it to the rest of the system as a secondary circuit with its own circulator. The two load circuits require the same water temperature, so he connects them as shown.
The following system has been planned with three 200,000 Btu/hr. boilers with plenty of capacity supplying a primary loop that serves several secondary loops.
Modern Hydronic Heating
for Residential and Light
Commercial Buildings by John Siegenthaler
Learn how to use the newest and most sophisti- cated hydronic heating materials and methods without compromising between comfort and energy. Features more than 300 diagrams of system piping/control schematics.
