Hi Guys,

Thanks for all the good info on the board.
I wanted to know if anyone had experience with the Grundos Alpha.

I have a simple set off of a buffer tank feeding four zones.
Is it as simple as using zone valves? It looks like when one or more zone valves open up, that the pump senses it and starts pumping. No wiring back from the zone valve to the pump.

Is this right? Thanks.

That's right. And, you can do the same thing with a Wilo Eco pump. Both of these pumps use ECM (electrically commutated motor) technology. As such, there is no need to use a pump switching relay. As we like to say, "Pipe It, Power It, Program It". The pump automatically sees changes in the system as zones open and close and adjusts flow accordingly.

ECM pumps can "dead head" with no problem since the motors do not generate heat. If all zones are closed, the pump goes into an idle state until a zone opens. It then adjusts flow depending on the number of zones open.

WILO_ECO_Brochure.pdf (154 KB, 20 downloads) Wilo Eco Brochure

That's pretty sweet. Do you like the Wilo better?

John, just noticed you work for Wilo - so I guess you do favor it. Thanks for the info.

Excellent idea.

Of course Grundfos and Taco both offer ECM circulators.

Now where is that Rob with the Toro?

hehehee

we're really liking the ecm circ, but we still power them up with thermostatic demands rather than dead-heading. if using one allows you to drop a pressure bypass, the economics aren't bad. otherwise, it's "greener", but it may not have a very good payback characteristic at today's electrical rates.

We just fired up a system with that Wilo Stratos as the only pump for a 4500+ sf single story house and so far are extremely please. The pump is so quiet you can't tell its running and it runs extremely cool.

By comparison the Tacos we used to circulate the water from the reverse cycle chillers to the tanks run hot and are making enough noise and vibration that we are likely going to have to swap them out.

John I'd like to give you or one of your local tech reps a call if you don't mind and see if you have something with an ECM motor that I can use as a replacement.

So John, this Wilo pump can be plumbed in and supplied with power and that's it? How on earth does it detect open or closed circuits? Maybe it turns itself juuuuuust a little and detects the resistance? Can this pump run continuously? How could I find out more about this pump - in plain English - not cryptic radiant expert-ese? Thanks.

the Wilo is pressure sensitive and it's always on.

the alpha is run like a regular pump though it too is pressure sensitive, so there are different takes on the technology.

Here's some info regarding a few of the posts above:

Wilo and Grundfos offer ECM technology; Taco does not. Taco uses a variable speed controller to adjust the speed of the pump, not ECM technology.

sbe and tibranth: You can contact me at 303-350-0023 if you want to talk more about the Wilo products. Or, you can email me at john.fantauzzi@wilo-usa.com.

tibranth: Yes all you need to do is power the pump and set the desired head. ECM technology uses permanent magnets on the rotor that are in alignment with the magnetic field of the stator. When the alignment gets off balance due to changes in flow from zones opening or closing, the "brain" of the pump corrects the speed to bring the fields back into alignment. This may increase or decrease the speed of the pump depending on system conditions.

NRT.Rob: The Wilo can be operated via a pump relay though it is not necessary. Eliminating the relay, associated control wiring, pressure differential bypass, and associated labor makes the ECM pump competitive with fixed-speed circulators plus better efficiency and system performance.

John, I'll give you a jingle. We don't need variable flow for the loop between the Reverse Cycle Chillers and the water tank but something that will run with a lot less vibration. Lower power consumption would be a nice bonus but isn't required.

Frankly I was shocked how much noise/vibration is coming off the Taco's. We're going to put some extremely soft tuned isolators in to replace the standard one that currently are on the rods that suspend the RCCs and pumps from the ceiling but it sure would be nice to have a smoother running pump to start with.

Its always a lot easier to start with low noise than high noise and try to isolate it.