A bit more on the UFH and Vaillant Heat Pump

[BartW]

HI,
Apologies for yet another thread, but I am still unsure what to do about UFH zones. 

 

A lot of valid comments have been made here: 

 

 

My dilemmas and some facts now:

 

- there will definitely be UFH on all 3 floors. Even if the upper floor UFHs are likely to get little to no use, I want them there for peace of mind.

- the biggest thing that I need to resolve is Vaillant Sensocomfort weather compensating programmer, or ditch that and control via UFH stats (and loose the benefit of weather malarkey)

 

The challenge in my head:

- Sensocomfort will operate downstairs

- First floor could get VR92 controller. This is essentially a £100 rather big thermostat with some fancy controls connected via Ebus to the rest of the system. If location be Hallway on FF, then its basic function would be "call for heat", and that would start the HP and open a bunch of actuators (assuming running as a group rather rooms), and start the circulating pump. These would connect to a local wiring centre, which would then connect back to the VR71 wiring centre (essentially a relay box with inputs and outputs and Ebus for comms). Does this sound like doubling a number of wiring centres?

- Top floor would have its own VR92 as above. This is to be run off the same manifold as FF.

- each floor level can call for heat, and make all room temps to rise up to the level dialled in on the VR92s. But with some rooms being smaller than others, am I going to be constantly under / over heating?

 

- part of me would want to control temps in the rooms, and maybe omit the local wiring centre, and get Loxone to open actuators. But as discussed, this would cause a lot of clashes. "who" calls for heat, when do we switch off, etc. 

 

So simplicity is key, and I get it.

 

In which case, do I need all actuators on the manifold? Do I manually balance the flow and leave it? 

I am sure many have done this before, I am just not seeing the obvious.

 

 

Any thoughts would be, yet again, most welcome.

Bart

 

 

 

[Nickfromwales]

Weather comp will complicate things if you wish to have different controls performing differently per floor.

Simplify this with an unified flow temp at source, and have room stats per room on ff and SF, and one global stat on the GF. Yes, you'll need actuators on the upper 2 floors, they will need wiring centres, but you should be able to leave the GF manifold as 'dumb'.

The different levels can have their flow temps manipulated via the mixing valves on each manifold to give you control over how aggressively the upper floors get heated ( so you are able to avoid overshoot ).

SF UFH will be a costly ornament.

[BartW]

Hi Nick, thanks. 
 

so am I reading this correctly?

 

- GF once balanced actuators off

- SensoComfort to control GF heat and feed weather comp info

- upper floors on stats. In which case they will just feed back to loxone relays and I will pick up temp readouts from Pure switches. 
 

this way upper floors heating will be conditional, i.e. only ever on once there is heat demand downstairs. Which somewhat makes sense?

[Nickfromwales]

The only issue that may exist is with weather conp, eg the GF is satisfied / at temp, zone valve closed & heat no longer being injected into the GF loops, but FF is still calling for a trickle of heat. 
How would the weather comp function when it’s essentially being told that the heat load is satisfied ( as the GF stat is then showing no call for heat ) but you still want the system to carry on running elsewhere. And vice versa ( FF satisfied and GF calling for heat ). 
I’m not familiar with modern Vaillant controls for heat pumps, so I’m unsure how the controls would apply WC to different floors on different controls at different flow ( injection ) temps.

 

Someone cleverer than me may point out something I’m missing here. 

[Nickfromwales]

Do you need WC in a PH? 

[BartW]

9 hours ago, Nickfromwales said:

Do you need WC in a PH? 

 

Sorry I am having a blonde moment... Water closet in a passive house? Whisky Coke in a pot of honey? I can go on, so please enlighten me 😆

[JohnMo]

WC = weather compensation 

[BartW]

Thanks,

 

@Nickfromwalesdo I need weather compensation?

 

I don’t know how the algorithm works, so not entirely sure…