UFH controls - conventional or home automation?

[Bonner]

8 minutes ago, Hilldes said:

Instead I have a new technology that derives energy from rotting vegetation that has lied dormant for millions of years ?

 

That’s  interesting, sounds like it’s carbon neutral ? ... on that note, I’ll get my coat ....

[IanR]

3 hours ago, joth said:

I've got a weatherflow tempest, and the loxberry integration for it works very well

 

Thanks for that, I hadn't considered a non-Loxone option for the forecasting.

 

3 hours ago, joth said:

I had intended to circulate UFH in this way (also copied the idea from Jeremy) but so far haven't found it necessary, 

 

My (house's) unusual proportions exaggerate the benefit of circulating the UFH. All habitable space is on the ground floor and due to the depth of the building (previously a cow-shed) we have a few rooms that have no direct light, so with those as well as the North-East and North-West elevation getting no solar gain we have less than a third of the area "benefiting" from solar gain. On the South-West and South-East elevations we have lots of full height glazing. This side of the building therefore over-heats quickly, and the rest is unaffected, so circulating the UFH triples the size of energy store available to the solar gain and helps equalise the building temps.

[joth]

1 hour ago, IanR said:

Thanks for that, I hadn't considered a non-Loxone option for the forecasting.

 

To caveat my suggestion, I'd say the Tempest weather station itself is so-so. Very clever design, except it's made in California and has unrealistic expectations about how well a solar-powered only device can work in our winters. And their silly wifi bridge seems unreliable and need a periodic reboot. If the station itself had the option of  PoE it would be much nearer a strong recommendation.

The lifetime subscription to their cloud API for forecasts is nice though (at least until they turn that down...)

[jack]

3 hours ago, IanR said:

Thanks for that, I hadn't considered a non-Loxone option for the forecasting.

 

I'm sure there's another option that relies on a free API at some weather site. I think the only limitation is the number of calls you make to it, and it's at least tens a day for free. Can't remember what it is though - might be mentioned on the Loxone Google group. 

 

3 hours ago, IanR said:

My (house's) unusual proportions exaggerate the benefit of circulating the UFH. All habitable space is on the ground floor and due to the depth of the building (previously a cow-shed) we have a few rooms that have no direct light, so with those as well as the North-East and North-West elevation getting no solar gain we have less than a third of the area "benefiting" from solar gain. On the South-West and South-East elevations we have lots of full height glazing. This side of the building therefore over-heats quickly, and the rest is unaffected, so circulating the UFH triples the size of energy store available to the solar gain and helps equalise the building temps.

 

We have some similarities. Floor to ceiling windows to the east and south corner of the kitchen at the east end of the house, and little to no solar gain anywhere else on the ground floor. 

[Dan F]

23 hours ago, IanR said:

Nope, the MVHR wet heat exchanger is run from the same buffer as the UFH, so at best it trims temps. The difference in energy delivery that 7°C chilled water to the MVHR would make compared to 14°C hasn't encouraged me to add additional insulation to UFH manifolds and a few pipe runs (that use the same buffer) in order to avoid condensation.

 

We've already insulated our first-floor MVHR manifold and pipework so will be running two circuits with different temperatures.  We have overhangs and loxone-automated blinds, but MVHR cooling is our only active first-floor cooling (no fancoils) so we wanted to ensure we could, if really required, run it at 7C.

 

23 hours ago, IanR said:

Loxone does a bit more for me as it gets ASHP, UFH, MVHR, vents and blinds all working together, by deciding whether to do nothing, take passive measures, or to heat/cool, and then get each system to do its part, as well as running MVHR boost, and DHW circulation loop based on presence sensing within the bathrooms.

 

Yes, that was all a given, although it would be interesting to understand a bit more about your approach, before I start programming our setup.  Have you shared this anywhere?

 

What I was trying to work out was what, if anything, you were doing with you heating system aside from callling for heating/cooling and letting Nibe do it's thing.  It seems you are:

- Doing the no-heat UFH recirculation when required.

- Manually controlling the circulation pumps, rather than letting Nibe fire these up automatically when you call for heat, to enable you to accumulate heat in the buffer without heating the house and then heat/cool the house from the buffer later.

 

Both great ideas!  I might try to twist our ASHP installers arm to enable the UFH recirculation, but in my case the buffer we are using is only 25L so it makes sense to juat call for heat and let Vaillant do everything including manage the buffer temp, run circulation pump(s) and adjust heating circuit temps based on configured min/max temperatures and heating curve.

 

[IanR]

On 03/10/2021 at 00:10, Dan F said:

Yes, that was all a given, although it would be interesting to understand a bit more about your approach, before I start programming our setup.  Have you shared this anywhere?

 

I've only chipped in on other's posts if I feel something I've done is relevant.

 

On 03/10/2021 at 00:10, Dan F said:

What I was trying to work out was what, if anything, you were doing with you heating system aside from callling for heating/cooling and letting Nibe do it's thing.  It seems you are:

- Doing the no-heat UFH recirculation when required.

- Manually controlling the circulation pumps, rather than letting Nibe fire these up automatically when you call for heat, to enable you to accumulate heat in the buffer without heating the house and then heat/cool the house from the buffer later.

 

The actual call for heat is handled by the SMO40 Nibe controller, from the buffer return temp, rather than by Loxone. Loxone just enables/disables heating and cooling on the SMO40. This also helped have a clear line of responsibility for the ASHP installers. ie. their job was complete when the buffer and UVC were correctly heating or cooling without any argument as to whether Loxone is issuing the call for heat.

 

The pumps and UFH isolation valve are automated by Loxone, with a manual override that allows the delay to wait for some forecast solar gain, hopefully avoiding any call for heat.

[Hilldes]

Here is what we have wired for 'day 1'. We have actually wired one Salus auto balancing actuator per manifold as spark though it might affect the Wunda wiring centre without any. All decorators caps are left open on the other UFH circuits. The wiring is complete but waiting for gas to the boiler before we test.

 

[BartW]

Hi @Hilldes ,

 

This is very useful diagram, but I am struggling to understand where (and how) the auto balancing actuator is sitting / how it is installed. Surely they are made to be installed by way of screwing on top of a manifold port right? But if all your ports are open (actuators off), then where does it sit?

 

Also, did you need the zone valve per floor? I read it was not necessary?

 

Many thanks!

 

Bart

[Hilldes]

1 hour ago, BartW said:

Hi @Hilldes ,

 

This is very useful diagram, but I am struggling to understand where (and how) the auto balancing actuator is sitting / how it is installed. Surely they are made to be installed by way of screwing on top of a manifold port right? But if all your ports are open (actuators off), then where does it sit?

 

Also, did you need the zone valve per floor? I read it was not necessary?

 

Many thanks!

 

Bart

 

The Salus Auto Balancing Actuator sits on the return manifold on one of the longer loops - as shown in pic below - 5th loop from the left.  It is only required because the WUNDA wiring centre I selected requires at least one actuator in order to enable the pump and boiler call for heat. With a different wiring centre the actuator could be omitted I believe.

 

 

Yes, one zone per floor - the GF manifold shown.

[markharro]

I have a slightly different angle on this. We are building a passive house. UFH on ground floor only. I don't even have a £1 of budget for Loxone so the home automation solution for us will be Homekit using Thread/Matter devices. We are agreeing specs for our UFH/ASHP design at the moment and the installer has listed the provision of "room thermostats".

 

Any point for me in questioning these/their functionality etc?

 

thanks

[BartW]

1 hour ago, Hilldes said:

 

The Salus Auto Balancing Actuator sits on the return manifold on one of the longer loops - as shown in pic below - 5th loop from the left.  It is only required because the WUNDA wiring centre I selected requires at least one actuator in order to enable the pump and boiler call for heat. With a different wiring centre the actuator could be omitted I believe.

 

 

Yes, one zone per floor - the GF manifold shown.

Ok,

thanks for explaining.

 

Did you absolutely need zone valves? I would imagine particular UFH floors would not push any water through with their respective pumps “in the way”?

 

I have also still not made my mind up as to the vaillant heat controls for heat pump vs loxone. 
 

kinda being greedy here. Wanting to use loxone pure switches and their sensors to tell UFH what to do, but then Vaillant seems to be doing this with ease as well. 
 

Totally confused… 

[JohnMo]

3 hours ago, Hilldes said:

It is only required because the WUNDA wiring centre I selected requires at least one actuator in order to enable the pump and boiler call for heat. With a different wiring centre the actuator could be omitted I believe.

Or you just drive the pump from the thermostat switch.

 

I would use the manufacturer controller every time. Set it to weather compensation, balance loop flows. No thermostat other than the valiant control.  Operate as a single zone.

 

If you have a towel rad stick an electric element in it, to make it dual fuel.  Good for summer towel drying. Also gives you two zones to comply with building regs

[Hilldes]

3 hours ago, BartW said:

Did you absolutely need zone valves? I would imagine particular UFH floors would not push any water through with their respective pumps “in the way”?

 

Good question, would need a zone valve at least for the DHW. For the UFH manifolds, if you switch off the pump will that block all water flow thought the manifold? I would assume not but others I'm sure will know more than me.

 

3 hours ago, BartW said:

I have also still not made my mind up as to the vaillant heat controls for heat pump vs loxone. 

 

Mine is a gas boiler, for a heat pump using the heat pump controller may be better - as per @JohnMo...

[Hilldes]

4 hours ago, markharro said:

I have a slightly different angle on this. We are building a passive house. UFH on ground floor only. I don't even have a £1 of budget for Loxone so the home automation solution for us will be Homekit using Thread/Matter devices. We are agreeing specs for our UFH/ASHP design at the moment and the installer has listed the provision of "room thermostats".

 

Any point for me in questioning these/their functionality etc?

 

thanks

 Guess you would only need one room stat if you are not using devices such a Loxone Pure switches (or similar) a your room temperature sensor.

[JohnMo]

26 minutes ago, Hilldes said:

would need a zone valve at least for the DHW.

Not really, just use a 3 port diverter valve.

 

22 minutes ago, Hilldes said:

Any point for me in questioning these/their functionality etc?

My house started with a thermostat in each room, even with a big buffer ended with short cycling of the boiler.  Basically have run this winter with no actuators on the manifold on weather compensation. Big saving on gas consumption 25-30% even though this winter has been much colder for us than last year.  House temp pretty constant. Will be installing ASHP in the next month or so and intend to run just the same. But with a 3 port diverter diverting hot water to the cylinder as required.

[Hilldes]

3 hours ago, JohnMo said:

ended with short cycling of the boiler

Stupid question from me: how do you know if a gas boiler is short cycling? 

Edited February 12, 2023 by Hilldes

[JohnMo]

Mine was running for a few minutes while doing central heating, then being locked out for 10 minutes, this repeated over the day.

[Ewan]

On 12/02/2023 at 14:26, JohnMo said:

Not really, just use a 3 port diverter valve.

 

My house started with a thermostat in each room, even with a big buffer ended with short cycling of the boiler.  Basically have run this winter with no actuators on the manifold on weather compensation. Big saving on gas consumption 25-30% even though this winter has been much colder for us than last year.  House temp pretty constant. Will be installing ASHP in the next month or so and intend to run just the same. But with a 3 port diverter diverting hot water to the cylinder as required.

 

Do you still use the one thermostat in the hallway, or is that the internal weather comp panel? (been looking into this topic and I think you were doing this in Jan '22)

We've a Worcester boiler that can have weather comp attachments, considering the best way to run our UFH in our retrofit. Still have a tado system, potentially will use that to limit upstairs radiators, or perhaps just normal TRVs.

House will only require low flow temps to be heat pump ready.

Edited August 14, 2023 by Ewan

[JohnMo]

Basically I have swopped over to a heat pump.

 

But the weather compensation controller was/ still is in the lounge, I didn't do load compensation (no use with UFH), so that unit didn't operate as a thermostat. Have a single thermostat in hall.

 

Only thing you have to watch is in the shoulder months you don't need much output, so you need to calculate how much water stays engaged with the boiler - you need approx 50L to stop 6kW from short cycling. So you need to know your water volume and min turn down of your boiler at low flow temps.

 

 

[Ewan]

Thanks. We're going to have 100L in the UFH & Boiler is a Bosch Greenstar i, so turndown is 3:1 or 7-9kW I think. Considering our Heat Demand at -2.2deg is looking like 4.5kW we will see cycling at all times of year, but with enough water volume, hopefully not short cycling?!

I'm thinking Bosch Sense ii WC control as single control in hallway (& it's a thermostat if needed). Plumber is trying to push zoning, but I think this will be better. Not being crazy am I?

Edit, Sense ii looks like the old one, Bosch EasyControl has WC too.. need to read more to understand the differences here.

Edited August 14, 2023 by Ewan