monoflo hot water system

PORKCHOP

need some assistance on coverting circulators to supply side from return side to use the piping method PUMPING AWAY.  WE ARE REPLACING A 60 YEAR OLD BOILER WITH A NEW WEIL MC-CLAIN ULTRA 230 NAT. GAS.  WE ARE THINKING OF CONVERTING TO PRIMARY SECONDARY PIPING AND MOVING PUMPS TO SUPPLY SIDE.  THIS SYSTEM IS SET UP WITH A 1-1/2" MAIN THROUGH THE CENTER OF THE HOUSE TO THE OPPOSITE END OF HOUSE APPROX. 40 FT.  AT THIS POINT THERE ARE ECENTRIC TEE AND ELL TO SPLIT THE MAIN.  AT THE SPLIT ONE PIPE GOES TO THE FRONT AND ONE TO THE BACK OF THE HOUSE.  AS THIS PIPE MAKES ITS WAY BACK TO THE MECHANICAL ROOM THE RISERS ARE FED TO THE FIRST AND SECOND FLOORS.  BACK AT THE MECHANICAL ROOM THERE ARE TWO PUMPS ONE FOR THE FRONT SIDE OF THE HOUSE AND ONE FOR THE BACK SIDE OF HOUSE.  ALL RISERS HAVE MONOFLO TEES ON THE RETURNS AND THE LOWER LEVEL (BASEMENT) HAS MONOFLO TEES ON THE SUPPLY AND RETURN

PROBLEMS WITH THE EXISTING SYSTEM:  THREE UPSTAIRS RADIATORS NOT HTG.  BUT CUSTOMER CANNOT REMEMBER HOW LONG THIS HAS BEEN A PROBLEM.

#1 QUESTION IS SHOULD I LEAVE PUMPS LIKE THEY ARE AND ONLY INSTALL PRIMARY LOOP AROUND THE BOILER THEN RECONNECT SUPPLY AND RETURN LINES INTO THE LOOP.  OR SHOULD I MOVE THE PUMPS.

#2 QUESTION WE ARE ALSO ADDING A NEW SYSTEM TO A NEW ADDITION THINKING ABOUT INSTALLING A HOT WATER COIL THAT WILL BE LOCATED IN THE DUCT SYSTEM AND CONNECTED BACK TO THE  BOILER SYSTEM.  WILL THIS CREATE ANY PROBLEM.

THANKS FOR READING

RONNIE

The Steam Whisperer (Formerly Boilerpro)

What I do...

is install a  pump to the supply and then use zone valves on the returns.  That sounds like a huge house if it needs a 230,000 btu/hr boiler (5,000 to 10,000 sq ft.)   With a load that heavy you may want to use at least a ECM Motored pump or a variable speed ECM pump with delta pressure sensing so the pump can ramp up and down as the zones open and close.  If the water temperature needs are about the same for all zones, then the variable speed pump is probably not worth the extra money since it will be running full speed nearly all the time, since the zones will probably the open most of the time running on full outdoor reset.  I would try to match the water temp needs to the air handler with the existing system for smoother operation.  You may want to go to a high delta tee on the coil (ex. 180 in, 120 out at design) to help reduce return temps to that boiler.



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