Add a zone pump to a valve manifold

Grappa

Happy Thanksgiving all. Our home has in floor radiant and it all works well except for our great room. It almost feels like there isn't enough flow when other shorter zones are flowing, leaving the great room chilly at times. The 1-1/4" manifold is fed with a Grundfos Alpha which seems to be working as planned, but flow appears to favor the shorter loops in other zones over the multiple longer great room loops. I was thinking of swapping the great room valve for a small pump but I'm unsure of the consequences that two pumps in series might have on the remaining valved zones. Any thoughts?

neilc

picture of the circ, and manifold(s),
sounds like a flow adjustment to be made,
let's see.

Grappa

Thanks Neil. The home runs go to loop manifolds. The zones without valves have loop manifolds valves. The only zones that we currently have enabled are the basement slab, the great room, and the attached garage.

We have three bathroom manifold valves set allow a slight flow whenever the main pump is on. It's was a horrible design error to have tile bathrooms without their own thermostats. We found it's impossible to balance bed/bath heating with flow control alone.

The great room has 5 loops in the 210' to 280' range, with a 6th one for a hall & powder that's 160' dialed all but off. I do feel it's a flow issue too, but I'm been unsuccessful at tuning it.

Attached should be a pic of the main manifold and a graph of boiler data.

SuperJ

Sounds like you need to balance the flows. There are device's like the Caleffi quick setter, that you can use to setup your flows.
https://www.caleffi.com/usa/en-us/catalogue/quicksettertm-balancing-valve-132432a

In the meantime, you can throttle the hand valves to the zones that seem to be getting too much flow. If you open the valves one zone at a time you could use the indicated flow on the pump to assist in setting the valves up.

It might be helpful to measure the return water temperature as you are doing this. Warm return temps may be an indicator that the zone has more flow than it needs. If it's infloor the temperatures won't change very quickly, so this process might take days/weeks to tweak.

neilc

so on the loops going up,
I see master, bonus, main, guest, loft, AF, and ?domestic?(unlabeled?)
or are we talking bout the 8 loops below ?
I'm seeing too much tubing, or not enough labels.

you have enough valves there that you should be able to choke the uppers, by feel, temp, on the return,
and you seem to be showing flow on the lower manifold,
if by choking the upper some, you may force more flow to the lower,
but from here I am not sure which loop serves where, or how to direct you.
Guess I'm asking which are the great room.

SuperJ

Balancing your flows is definitely the first priority, but here is another thing to try in addition to balancing. Make sure the circuit balancing valves are open on the manifold.

The pump maxes out at about 45 watts, what is the wattage displayed when everything is open? If you are on the highest constant pressure setting and still not at 45 watts, you could go to AutoAdapt and leave it there for a week(it tunes itself over time), AutoAdapt has access to a broader range of operation than any of the constant pressure curves. At low flow rates it will probably run less pressure, but at high flow rates it may push a little more since it runs in a proportional pressure mode (higher pressure target at higher flows).

Gordy

You have 4 circulators in the picture with the on board boiler circulator.

On board runs boiler loop.
One for DHW.
One for secondary piping.
Another for a remote manifold?

What is the far right vertical piping feeding?

Interesting mix of zone valve control, and pump controlled zones.

Grappa

SuperJ, yes I know it's a flow issue. I have a wide range of loop lengths in various zones and I'm struggling with getting them balanced. I have a few small tile zones that I leave on always since they're part of the disabled bedroom sub-manifold. I've tried using the Alpha display as a crude flow meter without much success. The individual flow meters on manifolds are worthless. I normally see 3-4 GPM 35W-40W range.

neilc, the home runs are headed up, basement slab is below. The AF (HX/antifreeze) loop is our garage. The right PEX loop is a future towel heater Domestic is all copper, before the Alpha, circ under the exp tank.

All home runs feed stainless loop manifolds (sub-manifolds). Some of the loops have valves on the sub-manifolds when they're serving shared spaced. Others like the main (great room) feed a single space and are valved in the boiler room.

I always balance using the loop (circuit?) valves at the sub-manifolds. All ball valves are full open.

Gordy, yes 3 external circulators and one inside the boiler. The Alpha is the main circ, DHW is below the tank, the 4th under the boiler is for a future towel heater. Boiler was a Solo110, but I modified it to a Solo60 to stop short cycling. Plans called for 79kBtu, but the 110K was way too much. The 60K works great even when we've been below zero.

Interesting good, or interesting bad? Attached should be a few schematics. It's functionally very close, main manifold zones vary from the print, the loops lengths are very close.