In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
The right system circulator with a Viessmann WB2B 35
I have a Mono Flo single main system designed in the mid 50's that I am installing a WB2B 35 into. The original system has a 2" main that splits into two 1 1/4" branch mains. The branches are currently zoned with B&G 100 circulators installed on the returns which then tee back to a 2" return main. The branches are balanced with a pair of gate valves with thermometers located in front of The circulators.
The Viessmann is designed not to have zones and I do not need them. I am reworking my near boiler piping to Viessmanns System layout 2 using the Viessmann low loss header and recommended Grundfos boiler and DHW circulators. I am planing to do away with the B&G's and use a single system circulator on the 2" main supply.
My question concerns the system circulator. I have a calculated head loss of 4.8 ft and flow of 8.2 gpm @ a 25 deg delta. I am interested in using a Taco Bumblebee to maintain a constant delta t across the reset curve. My concerns are weather I should use a delta t circulator and with the varying flow will I be able to balance the system by throttling the existing gate valves or should I do it another way?
I have about 1800 sq ft of emitters with a design heat loss of about 109,000 BTUH so I only need about 125 deg for a design temp. We only hit the design temp here a few days a year so if I can hit a delta T of 25 Deg I should be condensing almost all of the time. I really don't care about anything beyond consistent comfort and economy so what ever circulator I need to do that with will be fine. I was just thinking that a variable speed pump would likely give me a nice consistent room temp across the reset curve. I have put a lot into calculating my head loss so I hope it is correct. Compensating for head loss is another atractive advantage of the Bumblebee. I also think it is cool that it displays the current flow.
As usual I would appreciate any thoughts you guys have and I do not mind learning I am wrong. That is how I got this far.