Grundfoss Alpha settings

Sounds like you have the Alpha supplying a primary loop off the buffer and then individual zone pumps? If so, there is nothing changing the pumping demand on the Alpha. It just pumps at relatively constant volume with some flow being pulled to zones (or not) and the rest going around the primary loop back to the pump. You are still using about 30% less electricity than if you had a traditional circulator, but in order to take maximum advantage of the Alpha's variable speed capability you would need to have separate supply and return headers with zone valves instead of pumps, IIRC.

Mine runs 2 baseboard zones and I leave it set on constant pressure #1. When the zones are closed it turns at 4 watts and 0 gpm. With 1 zone open it runs at 6 watts and 2 gpm and when both zones are open it runs at 7 watts and 4 gpm. I have temp gauges installed on both return lines and I'm getting an almost perfect 20 degree delta T. I couldn't be more pleased with it. Sure beats 2 pumps running using 170 watts !

huffdawg said:

How do I set up my Alpha 2 properly. It is on a loop that supplies the house loads and it draws from a 150 gal. buffer tank.
The house loads draw off the Alpha 2 loop via closely spaced tee's and their own pumps. on the discharge side of these pump with exception of the DHW pump are zone valves .

I have the Alpha 2 set on Auto Adapt and it is sending 8 to 10 gpm . even when no loads are calling . Should I set it to something other than Auto Adapt.

Cheers

Huff

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I think where these pumps 'shine' is when you have mutiple heat emitter zones with zone valves only, that are connected to a header supply return manifold. Instead of a differential pressure bypass valve the auto adapt feature will take its place and save you electricity when it can. It also helps to balance the circuits.

i see a very noticeable differance in gpm's when my differant zones are calling given there is significant differance in the number of loops in the zones and i am on autoadapt.