Loxone heating controls vs standard actuators and a hybrid of the two

[BartW]

Hi,

I am reading more and more into the whole smart home thing and am now diving into the depths of other logics that could replace the expensive parts of the system.

 

(KNX is another system that I am considering for the build, but let's leave this one for yet another thread).

 

 

For now:

 

With Loxone UFH actuators being £79 + VAT each, and me needing 12no of them, that is a whooping £950 + VAT for just actuators. I appreciate these connect directly to tree, and come with their own addresses, etc, so easier to programme.

 

Now, my UFH split (across 3 floors and 3 manifolds) is:

- Top Floor Gym (2 loops / actuators)

- FF Master (2 loops / actuators)

- FF Bed 2 (2 loops)

- FF Bed 3 (2 loops)

- GF Guest (1 loop)

- Open Living / Dining / Kitchen (3 loops)

 

Surely I could use standard £2 actuators, link them up in twos and threes, and run them straight off the Miniserver's relay outputs, or even relay extension? Actuators are merely rated @ 2W / 230V, and nominal current draw.

 

Am I missing something?

Thanks

Bart

 

 

 

[Dan F]

Yes you could, not missing anything.  What is your heat source?  If your house is well-insulated I'd consider the following though:

- Not trying to control UFH on a per loop/room basis, but rather per-floor.

- Have your heating controls control 3 heating zones, rather than an external system.

[JohnMo]

Really you should consider keeping it simple. UFH doesn't need complex control system or smart anything.

 

Simple wiring centre, have each floor as a zone, or even the whole lot as a single zone. The more you split the system in to small parts the more likely the heat source will short cycle and burn through energy.

[BartW]

Thanks!

 

So the house is a TF construction that we are slowly building as we speak. Thermal envelope is designed to 0.15u Value. I have probably overkilled the roof a little, so that is probably a bit better. 

 

The whole house will be run from a 7kW Vaillant AroTherm Plus with UniTower. Solar PV available for surplus discharge, etc.

 

 

The reason we wanted the rooms at different temps is to give flexibility to the occupants. Master Bedroom is the one that is likely to be lived in for some time forward, then Bed 2, and so on. We are a young "growing" family still.

 

Downstairs is mainly open and that will have a lot of residual heat all around. Guest Bedroom will double as an office, and we would like that to be a tad cooler to aide working.

 

Top floor Gym will get used either morning, or evening. 

 

We just don't want to cook the house 24/7 when only minor parts are likely to get used, and in different ways / dynamics.

 

Wunda Trade smart heating or tado was going to be a go-to, but then I decided that I could do things smarter.

 

Say, one room + presence sensor per room would allow controlling of:

- lights (when one leaves the room and forgets to switch things off)

- heating (to pick up temp from the sensor)

- MVHR (to pick up CO2 and humidity from the said sensor)

- ability to control whilst out

- and all the usual things

 

I am just trying to build the infrastructure in such a way that I would be able to smartly automate it, and forget about it, but be able to conveniently override when I need to.

 

For the above reasons KNX is starting to sound more attractive (bar learning to programme it), because most things are KNX compatible, just not Loxone ready. Zehnder MVHR will communicate with it, I am likely to be able to build a simple algorithm for heating using some Chinese relays from Alibaba, and if I really want to I could add 1Home integration and have it all sing and dance with Apple Home Kit.

 

 

Elaborate, I know, and I am sorry.

 

 

 

 

[Dan F]

12 minutes ago, BartW said:

The whole house will be run from a 7kW Vaillant AroTherm Plus

We have one of these and it's effiicienlty managing 2 zones using weather compesation with no use of seperate UFH controls.

 

13 minutes ago, BartW said:

The reason we wanted the rooms at different temps is to give flexibility to the occupants. Master Bedroom is the one that is likely to be lived in for some time forward, then Bed 2, and so on. We are a young "growing" family still.

Reasoning makes sense, but in a modern well-insulated and airtight house its harder to do this  effectively and per-loop controls risk conflicting with ASHP controls with potential for short-cycling and reduced efficiency as @JohnMo also mentioned.

 

16 minutes ago, BartW said:

For the above reasons KNX is starting to sound more attractive (bar learning to programme it), because most things are KNX compatible, just not Loxone ready. Zehnder MVHR will communicate with it, I am likely to be able to build a simple algorithm for heating using some Chinese relays from Alibaba, and if I really want to I could add 1Home integration and have it all sing and dance with Apple Home Kit.

That would certerinaly be a much more complex route that using something like Loxone.  You are right Loxone can't integrate with everything out of the box, but you can expand it's functionality via LoxBerry or even using a KNX extension if needed.  With the MVHR you can integrate using simple volt-free contacts for simple things like boosting, if you want full contol and all the data then you can use Loxberry plugin: https://wiki.loxberry.de/plugins/comfoconnect/start

[BartW]

8 minutes ago, Dan F said:

We have one of these and it's effiicienlty managing 2 zones using weather compesation with no use of seperate UFH controls.

I am intrigued.

So AroTherm / Unitower manual lists a couple of add-on parts that effectively allow splitting heating into more than one circuit. Is that what you are referring to? It's the last page in the schematics page below: https://midsummerwholesale.co.uk/pdfs/arotherm-plus-schematic.pdf Yet that splits between UFH and rads, rather than 2 UFHs. I also have another floor with just a single room in it. That call for another manifold. Unless I move the FF manifold to Second Floor and drop pipe runs into the rooms. A bit more pipe, but eliminates one circulating pump, some brassware and so on. Saves energy too at 60W-150W per hour which has some meaning, right?

 

 

14 minutes ago, Dan F said:

Reasoning makes sense, but in a modern well-insulated and airtight house its harder to do this  effectively and per-loop controls risk conflicting with ASHP controls with potential for short-cycling and reduced efficiency as @JohnMo also mentioned.

 

I can sort of see this happening. I just need to unmarry my idea...

 

 

16 minutes ago, Dan F said:

That would certerinaly be a much more complex route that using something like Loxone.  You are right Loxone can't integrate with everything out of the box, but you can expand it's functionality via LoxBerry or even using a KNX extension if needed.  With the MVHR you can integrate using simple volt-free contacts for simple things like boosting, if you want full contol and all the data then you can use Loxberry plugin: https://wiki.loxberry.de/plugins/comfoconnect/start

 

I am not sure I would want to add yet another sublayer to the whole thing...

[Dan F]

15 minutes ago, BartW said:

So AroTherm / Unitower manual lists a couple of add-on parts that effectively allow splitting heating into more than one circuit. Is that what you are referring to?

With the VR71 you can use 3 mixed (or unmixed) circuits.  You can do even more than 3 circuits if required with additional VR71's I think. These circuits can be UFH, radiator, fancoil or anything.

 

15 minutes ago, BartW said:

I am not sure I would want to add yet another sublayer to the whole thing...

It's more of a companian to Loxone (running on a rapsberry Pi) to integrate with additional things including internet weather services etc, than an additional layer.  With a KNX-based approach, have you thought about if you would have a central "server" with nice app for everyone in the family to use? Have you thought about how you would integrate with things that may only have a cloud API and not a KNX adapter?

Edited December 28, 2022 by Dan F

[BartW]

34 minutes ago, Dan F said:

With the VR71 you can use 3 mixed (or unmixed) circuits.  You can do even more than 3 circuits if required with additional VR71's I think. These circuits can be UFH, radiator, fancoil or anything.

Ok, so I have SensoComfort and Sensonet on my order, but I might have to review. But I think I get it. You would simply use VR71 as a wireless control centre to send triggers to the UFH manifolds to start the pump, and send a trigger to the pump? Much like traditional UFH with respective thermostats + wiring centre? (ish?)

 

36 minutes ago, Dan F said:

It's more of a companian to Loxone (running on a rapsberry Pi) to integrate with additional things including internet weather services etc, than an additional layer.  With a KNX-based approach, have you thought about if you would have a central "server" with nice app for everyone in the family to use? Have you thought about how you would integrate with things that may only have a cloud API and not a KNX adapter?

 

I have, and am a bit nowhere still with it. I appreciate different type hubs come with different UIs. This then leads to it become another Loxone, just with a lot more sweat required. One big benefit for KNX seems to be cost of particular accessories, and the fact that there are a lot of manufacturers making components. And of course, the fact that KNX is a common layer for many solutions I am considering, whereas with Loxone I would need the £600 accessory to make the two speak. Oh, and depending how realistic, if the Loxone hub fails I loose everything to include lights, etc. If KNX hub fails, all will still work because it is decentralised right? 

[MikeSharp01]

This feels like the age old challenge of trying to navigate past the technology wins that proprietary systems want to make so as it keep you in their fold all the way through. While I get the basic business logic of this idea for the companies concerned (Loxone / Honeywell / ....) it makes very little sense otherwise for several reasons.

 

Firstly from the overall efficiency point of view as none of these companies do it 'all' and they always end up needing / offering interfaces that allow the bits they don't do to be sourced elsewhere - it is in fact classic defender mentality at work. Secondly wanting a sophisticated system does not / should not equal getting a complex or chaotic one. Open source thinking like MTTQ & node RED, similarly maker technologies like - RPi / Arduino, do allow the construction of accessible systems albeit without sophisticated documentary support and, thirdly, in the era of IoT I am not sure that many of the proprietary systems will last. As it will be expected that your whole automation system, and its component sub systems, is / will be just a node on the IoT and should be open to a conversation just like you and I could have and will be demanded by the likes of Alexa and what will follow. KISS is still a great concept - Keep It Stupidly Simple. (Yes not keep is simple stupid as I would not wish to insult anyone.) Eventually, given this is likely to be mass market - as we all demand better control of our energy use, in the end, once the adoption curve starts to play ball, the 'VHS' solution will emerge and most of these systems will fall by the wayside! No one will be buy an actuator that does not expose its capabilities and control parameters on the IoT or, for that matter, a sensor that does not do the same. Then the technology winners will be the ones who make the higher level stuff (software) that allows these things to work together and offers a robust self documenting interface anyone can use / understand.  

[JohnMo]

Could your grandmother change the temperature or switch on the heating, if the answer is yes, wonderful, if no, does it belong in a house.

 

You get run over by a bus, could a 'normal' electrician or plumber fix it? Without spending hours scratching their head? See above.

 

Mines confusing to most plumbers  - because I have a big buffer cylinder.

[ProDave]

3 hours ago, BartW said:

The reason we wanted the rooms at different temps is to give flexibility to the occupants. Master Bedroom is the one that is likely to be lived in for some time forward, then Bed 2, and so on. We are a young "growing" family still.

 

Downstairs is mainly open and that will have a lot of residual heat all around. Guest Bedroom will double as an office, and we would like that to be a tad cooler to aide working.

 

Top floor Gym will get used either morning, or evening. 

 

We just don't want to cook the house 24/7 when only minor parts are likely to get used, and in different ways / dynamics.

With the U values you are having (good) you will struggle to get different rooms at different temperatures.

 

We have no heating upstairs and the upstairs only gets heat from downstsairs, and the coldest it has got in the bedroom when it was -10 outside, was 17 degrees (downstairs 20 degrees)

 

If your top floor is just a gym, which you probably don't want overly hot, then I would not bother with any heating in it at all.

 

This was a bit of a leap of faith.  Plenty of people had told me no heating needed upstairs, and coming from "ordinary" houses I simply did not believe this to be so, and like many before me I put electric points in the bedrooms for an electric panel heater so that when it got too cold they could be heated.  Those remain unused as they do in many others who did not trust the no heating needed concept and put them there just in case.   I expect if you don't heat your gym, you will put some heater points in.......

[BartW]

9 minutes ago, ProDave said:

Those remain unused as they do in many others who did not trust the no heating needed concept and put them there just in case.   I expect if you don't heat your gym, you will put some heater points in.......

Fair point, and it has crossed my mind, but cost to put in UFH for the gym is about £500 at this stage. Slightly more if I consider hi spec controls. 
 

two pretty heaters capable of doing the same later would be similar money. 
 

The gym room will be insulated for sound. This comes with a certain level of heat blocking too. On the flipside, the two bits of glazing cover 13m2. That is about 30% of walls, of which four walls, three are external ones. 
 

one thing I could simplify is to move first floor manifold to the loft at gym level and merge the two. My cost for the gym ufh would halve due to omitting of the extra pump, valves and some brassware. The pump is capable of 8m head. It would only need to carry 3m vertically whilst having loops rather medium length. 
 

hmm…

[Dan F]

2 hours ago, BartW said:

You would simply use VR71 as a wireless control centre to send triggers to the UFH manifolds to start the pump, and send a trigger to the pump? Much like traditional UFH with respective thermostats + wiring centre? (ish?)

It's not wireless.  It's wired (via ebus) to all the other Vaillant stuff and has input for temp sensors and outputs for zone valves and mixing valves.

 

 

[BartW]

6 minutes ago, Dan F said:

It's not wireless.  It's wired (via ebus) to all the other Vaillant stuff and has input for temp sensors and outputs for zone valves and mixing valves.

 

 

Thanks!

 

I will read about the other two and compare, but really good hint. 
 

has it got an app?

[Thorfun]

59 minutes ago, BartW said:

Fair point, and it has crossed my mind, but cost to put in UFH for the gym is about £500 at this stage.

i was told i wouldn't need heating in my basement but i installed UFH loops throughout just in case. total materials weren't much more than £500 and we fitted it ourselves so no labour costs. for that sort of cost it's a no-brainer to install even if you never use it in my opinion.

[BartW]

8 minutes ago, Thorfun said:

i was told i wouldn't need heating in my basement but i installed UFH loops throughout just in case. total materials weren't much more than £500 and we fitted it ourselves so no labour costs. for that sort of cost it's a no-brainer to install even if you never use it in my opinion.

and this is exactly my thought process here. 

[Hilldes]

@BartW I asked a similar question on Loxone control options.

 

Same concern - that for 23 UFH loops in our case a Loxone actuator for each loop was prohibitively expensive. I was also not sure we would need to control each room individually - highly energy efficient fabric + MVHR.

 

I basically implemented this as an interim option:

• Just two UFH zones - GF and FF. Each floor has one Loxone Touch Pure switch - this provides the actual temperature for the floor.
• In Loxone Config, each floor has one Intelligent Room Controller - this takes the actual temperature from the Touch Pure switches and enables the setting of the target temperature via the app. Basically this is a software thermostat that will control a Loxone relay - that will call for heat for the relevant floor.
• Each floor was a Wunda UFH writing centre. The Loxone relay output connects to the Wunda wiring centre as if the Loxone relay was a simple mechanical thermostat. All you need then is a single Salus Auto Balancing Actuator for each floor - which connects into the Wunda wiring centre. The Wunda Wiring centre then manages the zone valve and boiler call for heat.

 

Very simple, but so effective I have no plans to change it. As an example of how it performs, on the GF I have the temperature set point at 20 degC. In practice the actual temperature varies between 19 deg and 21 deg.

[JohnMo]

Little confused what the 2 Salus auto balancers will do, when you have 23 loops?  That will only control DT on 2 loops.  What happens to the rest?

 

Common theme today, making thing way more complicated that they need to be for no good reason.

 

People must be on holiday, plenty of time to over think and make as complicated as possibly.

 

Conversely I took all my actuators off today, so now running everything as a single zone, one central thermostat only set a couple of degrees higher than target, running WC.  Even the Salus actuators were never moving because all loops were alway open.

 

 

[MikeSharp01]

13 minutes ago, Hilldes said:

I have the temperature set point at 20 degC. In practice the actual temperature varies between 19 deg and 21 deg.

The very definition of hysteresis🙂.

[Dan F]

2 hours ago, BartW said:

Thanks!

 

I will read about the other two and compare, but really good hint. 
 

has it got an app?

 

Yes, they aren't different options, they all work together.  VR71 is the wiring centre, the sensoComfort is controls.  The most basic installs don't use VR71, but anything with more zones does. 

 

 

[Dan F]

39 minutes ago, Hilldes said:

@BartW I asked a similar question on Loxone control options.

 

Same concern - that for 23 UFH loops in our case a Loxone actuator for each loop was prohibitively expensive. I was also not sure we would need to control each room individually - highly energy efficient fabric + MVHR.

 

I basically implemented this as an interim option:

• Just two UFH zones - GF and FF. Each floor has one Loxone Touch Pure switch - this provides the actual temperature for the floor.
• In Loxone Config, each floor has one Intelligent Room Controller - this takes the actual temperature from the Touch Pure switches and enables the setting of the target temperature via the app. Basically this is a software thermostat that will control a Loxone relay - that will call for heat for the relevant floor.
• Each floor was a Wunda UFH writing centre. The Loxone relay output connects to the Wunda wiring centre as if the Loxone relay was a simple mechanical thermostat. All you need then is a single Salus Auto Balancing Actuator for each floor - which connects into the Wunda wiring centre. The Wunda Wiring centre then manages the zone valve and boiler call for heat.

 

Very simple, but so effective I have no plans to change it. As an example of how it performs, on the GF I have the temperature set point at 20 degC. In practice the actual temperature varies between 19 deg and 21 deg.

 

You can do exactly this with the Vaillant without needing a Wunda wiring centre.  The easiest solution (which best supports weather compensation and optimum efficiency) is to have a Vaillant controller on each floor. If you want you can use an external call for heat (from something like loxone) but then it's a bit harder to leverage the weather compensation as well and there isn't a simple way to control ASHP flow temperature externally so doing your own weather compensation isn't easy.

 

44 minutes ago, Hilldes said:

single Salus Auto Balancing Actuator for each floor

 

My understanding was that these are designed to be used one-per-loop, and will automatically constrain flow on shorter loops to self-balance.  One per floor may help balance GF and FF (if they are on the same ASHP circuit), but you won't get per-loop auto-balancing.

[Dan F]

34 minutes ago, JohnMo said:

Little confused what the 2 Salus auto balancers will do, when you have 23 loops?  That will only control DT on 2 loops.  What happens to the rest?

@Hilldes must be using one for half of the loops and the other for the other half of the loops.  So each Salus actuactor is balancing 10 or so loops (as a whole) each.

[JohnMo]

Still confused as they only control a single loop, not sure how they would be a benefit or be attached, so one can control lots of loops

[Hilldes]

35 minutes ago, Dan F said:

@Hilldes must be using one for half of the loops and the other for the other half of the loops.  So each Salus actuactor is balancing 10 or so loops (as a whole) each.

 

That's right - one Salus on each floor and use the Salus on a longer circuit so it won't be closed prematurely because return temp is approaching flow temp. Only needed though to activate the Wunda wiring centre (and ensure it controls the zone valve and boiler). Mine is a gas boiler BTW.