How would Auto-Adapt (Alpha2) change my flow rates ?

Dave Carpentier

I have 7 zones in my slab, with lengths from 80ft to 400ft.
I use manual valves on the supply side to throttle down for balancing.
They're driven by one Alpha2, currently in constant pressure mode (12ft).
I marked on the graph where my current operating range seems to be. It might get a little more flow once all zones are open during the depths of winter, maybe out to 3gpm ?


(Auto-Adapt is the blue coloured zone)

What would change if I put it in Auto-Adapt mode, in the cases where I have slow flow now (in constant pressure mode) ? I think the garage (400ft) flows perhaps 0.25 gpm at 12ft of pressure.

hot_rod

7 zones or 7 loops in the slab?

Dave Carpentier

7 zones. One loop, tstat and actuator per room.

hot_rod

What is it you are trying to accomplish? More flow in that 400' garage loop?

The pump merely measures and responds to pressure changes. Trying to speed up or slow down based on increasing or decreasing head detected.
As I understand, the Auto Adapt wants to learn when these changes happen and plot an operating sequence.
Some suggest the current Auto Adapt was designed for TRVs, proportional valves, and may not be well versed to dumb, on/ off zone valves or actuators.

The 15-58 Alpha due after the first of the year seems to have better "system type" choices. I suspect the algorithms are more robust, so maybe radiant, radiators, or fin tube settings would help the circ better match the type of system.

Have you run it in fixed speed 3? Maybe something in the tubing is preventing you from getting more flow, or it is trying to run beyond it reach? A kinked tube? Something stuck in the manifold valve or port?

Dave Carpentier

I did run some tests at max rpm on that loop solo.
The display showed 43w and 1gpm, but extrapolating from the watts to the graph I would guess 0.7 gpm ? (I think it reads "1" for anything >0.5 and <1.5)

At the current rate, the garage does flow a bit slow and sheds heat where it passes thru a bedroom along an interior wall before it enters the garage. A bit more speed would shed a bit less afaik. Complaints that the bedroom overheats. I say just make a bookshelf unit with insulation under the bottom shelf to block that.. but Im still trying to win that one..

Im not sure how that Auto works, but I guess its not magic. Im thinking now that it would be on the same load curve.. and I would end up with lower flow than I have already.

hot_rod

Just a single 400’ loop in the garage? What size garage?

Zman

I have found that Auto Adapt often fails to recognize and adjust when only one or two loops are open.

Dave Carpentier

hot_rod said:

Just a single 400’ loop in the garage? What size garage?

19x30 and yes one loop. Im not 100% sure on the length, but that seems right. We did 2 passes at 6" by the walls and then 1ft spacing approx.

Do those metal 90deg sweep guides cause much resistance in 1/2" pex ?
There's 8 of those on the garage loop.
Boiler room turn to horiz in slab, comes out in garage above floor (garage slab is lower than house) and bends horiz, travels a coula feet then bends down and then bends horiz inside garage slab.

hot_rod

If the radius is 6D six times the diameter of the tube it is not counted as an ell in the pressure drop calculation

One loop in that garage will cause that zone to run a long time I suspect. And short cycle the boiler if it is the only zone calling..

So if the question is inadequate heat in the garage, it is under tubed.
As for flow through one 400’ loop, with what you describe .50 gpm should be obtainable