UFH controls - conventional or home automation?

[Hilldes]

Looking at options for controlling UFH (and DHW) when the house will have a home automation system (Loxone in my case). Options range from conventional UFH controls, where the HA systme is just a glorified timer to... making full use of availble HA controls. The UFH system has 12 circuits on ground floor and 11 circuits on first floor, all with Wunda premium manifoods and pump sets. There are 12 rooms that will need a room stat in each.

 

Here is an analysis of some options...

 

@jack, @joth, @Rob99 what have you done in your implementation(s)?

 

[joth]

31 minutes ago, Hilldes said:

Looking at options for controlling UFH (and DHW) when the house will have a home automation system (Loxone in my case). Options range from conventional UFH controls, where the HA systme is just a glorified timer to... making full use of availble HA controls. The UFH system has 12 circuits on ground floor and 11 circuits on first floor, all with Wunda premium manifoods and pump sets. There are 12 rooms that will need a room stat in each.

 

Here is an analysis of some options...

 

@jack, @joth, @Rob99 what have you done in your implementation(s)?

 

 

Option 3 for me, with some caveats

1. The UFH manifold does not have any zone actuators. They are sat in a cardboard box waiting to be installed. For now, the whole ground floor UFH comes on/off together. (Likewise the upstairs FCU)

2. I used Touch, not Touch Pure switches, and just for the "main" switch in main rooms, so about £500 

 

How well insulated is your house? Will you need zone based control?

Do you actually like the Touch [Pure] switched to use? Are you okay having to (repeatedly) explain them to every house member and guest?

I think those are the main questions I'd ask to guide a design.

 

At the moment my loxone-> heat pump integration is just a couple relays on the two zone "call for heat" inputs. (UFH and FCU). While loxone programming (which I do myself) is needed to adjust details, a future owner could easily unhook the two and use the Ecodan room stat instead.

If I do install the manifold actuators it'll probably be just for the self balancing feature, but if start using them for more fine grained control of the downstairs loops it will definitely entangle loxone into the heating system a lot more. 

Loxone also controls skylight opening for automated stack venting, blinds, boosting ashp when there is cheap/free electricity available, towel rads, electric UFH in the ensuite, MVHR boost, and putting stuff into eco mode when we're away,  so I appreciate having all that logic together with a single system acting as source of truth for what should be happening

 

Edited October 1, 2021 by joth

[IanR]

Do you have any other "systems" for heating, cooling, avoiding solar gain?

 

For me it was an easier decision to have Loxone controlling the UFH as I also wanted to control the MVHR, roof vents and external blinds to ensure everything was working together to either heat, avoid heat or cool the house.

 

Loxone decides whether the house is heating, cooling or taking passive measures using an average of all the temps from the Touch Pure light switches in each room AND comparing the temp of those rooms effected by solar gain with those that are not AND comparing the slab temp in those rooms effected by solar gain with those that are not.

 

Loxone then decides whether to just circulate the UFH, without any heat/cool input in order to distribute solar gain, or to employ blinds and/or vents, or to heat/cool the buffer and distribute that heat/cool via UFH and MVHR.

I have Loxone actuators on each loop of the UFH as well as relays to control the UFH pump, MVHR wet heat exchanger pump, DHW loop pump and a valve on the UFH splitter manifold that separates it from the buffer when it's just circulating the UFH to distribute solar gain.

[Hilldes]

46 minutes ago, joth said:

How well insulated is your house? Will you need zone based control?

 

A very good question. SAP is 85 B, so quite well insulated. And MVHR I think moves air around the house so making zones less isolated. I hadn't thought of not having zones. So right now you control each floor manifold via a single stat?

[Hilldes]

45 minutes ago, IanR said:

Do you have any other "systems" for heating, cooling, avoiding solar gain?

 

Have no cooling and no blind automation. Have installed MHVR but no plans to integrate. So Loxone basically controlling lighting and heating.

[jack]

2 hours ago, Hilldes said:

@jack, @joth, @Rob99 what have you done in your implementation(s)?

 

Mine is extremely simple. We have 8 loops downstairs, all run as a single zone. No UFH upstairs. Temperatures from a handful of cheap 1-wire temperature sensors upstairs and downstairs are averaged within Loxone and used to call for heat from the ASHP via a relay. I decide when it's heating season and switch the ASHP mode accordingly. I could automate this, but I only have to do it a couple of times a year, so it's no real effort.

 

I've read some reports about the Loxone control valves being unreliable. I think there was a tendency for something to break off internally. Worth a look at the Google Groups Loxone group for discussions about this if you're considering using them. I believe people may have used other types of port valve and controlled them with, eg, a PWM or 0-10V output.

 

As for passive controls, we have external blinds. Again, I've kept it as simple as possible. They all come down automatically at dusk. Certain ones come up at 7 in the morning every morning, others only on weekdays, and yet others only at certain times of the year. For example, our east-facing kitchen blinds stay down in the morning during summer when we're concerned about solar gain. The blinds on the front of the house stay down but tilted slightly open all day in winter and summer. I'll occasionally manually open them fully if it's a sunny afternoon and I think the solar gain is worth it.

 

I haven't actually programmed the system to automatically change behaviour over the seasons. I generally just nip into the Loxone config program at the change of seasons and manually change the programming. Takes about 3-5 mins twice a year. One day I'll get around to programming the relevant changes as a button on the interface (or, perish the thought, automate it completely), but I have other things ahead of this on my to-do list. 

Edited to add: MVHR is not currently controlled by Loxone. It's generally just left to its own devices. The only time I hit boost is if we're cooking something smokey like steaks.

[SuperJohnG]

I think options like this are overcomplicated. The effects of different UFH zones and high levels of automation  in a highly insulated house with MVHR add not very significant levels of value for the amount of effort.

 

Keep it simple, as few zones as possible and enjoy your time in your house rather than constantly managing systems. 

 

I have no UFH upstairs, 11 loops downstairs with 4 zones. 

 

Zone 1 - big open plan kitchen living room area with a glazed gable,

Zones 2 - donwstairs bathroom, dimply as I'd like a warm floor in there.

 

zone 3 - everywhere else downstairs within within house. 

 

Zone 4 - which is my integral garage but rhats only like that so in future if I turn it into a room I can control it. 

[joth]

1 hour ago, jack said:

Mine is extremely simple. We have 8 loops downstairs, all run as a single zone. No UFH upstairs. Temperatures from a handful of cheap 1-wire temperature sensors upstairs and downstairs are averaged within Loxone and used to call for heat from the ASHP via a relay.

 

This is very much like my setup.

 

One other thing I've found is that while I do use the Touch temperature sensors to control automatic shading in rooms with a tendency for overheating in summer, for the whole house temperature I've found it even better to use the MVHR "indoor temperature" sensor as the guide. This is effectively a ready made average of the entire house temperature so extremely simple to use to guide heating / cooling.

 

Automatic roof window opening at night time, for stack cooling, is probably the single biggest utility of the entire loxone install, somewhat to my surprise as I only added it as an afterthought. It's incredibly effective, and again I use the MVHR "outdoor temperature" sensor as a very reliable guide as to when stack venting will be useful to enable. (the MVHR "bypass status" would also be a good signal for this, as it ensures that the mvhr and heating/cooling are not in danger of fighting each other)

 

 

 

[Hilldes]

1 hour ago, SuperJohnG said:

I think options like this are overcomplicated. The effects of different UFH zones and high levels of automation  in a highly insulated house with MVHR add not very significant levels of value for the amount of effort.

 

Keep it simple, as few zones as possible and enjoy your time in your house rather than constantly managing systems. 

 Thanks, that is what I'm now thinking based on Joth's post. I guess though, as soon as a manifold serves more than one zone then each circuit/loop on that manifold will need an actuator? 

[Hilldes]

2 hours ago, jack said:

I've read some reports about the Loxone control valves being unreliable. I think there was a tendency for something to break off internally. Worth a look at the Google Groups Loxone group for discussions about this if you're considering using them. I believe people may have used other types of port valve and controlled them with, eg, a PWM or 0-10V output.

Thanks Jack, will do some research on theses products.

[jack]

1 hour ago, joth said:

One other thing I've found is that while I do use the Touch temperature sensors to control automatic shading in rooms with a tendency for overheating in summer, for the whole house temperature I've found it even better to use the MVHR "indoor temperature" sensor as the guide. This is effectively a ready made average of the entire house temperature so extremely simple to use to guide heating / cooling.

 

Yes, I'd initially planned to use that temperature, but the module needed to allow me to get that value from the MVHR unit into Loxone was quite expensive, so I haven't bothered. I did consider adding a one-wire sensor into the outgoing airflow duct and using that - I might still try it at some point when I get some time (maybe in about a decade at the current rate of progress through my to-do list!) 

 

I also considered adding a temperature sensor on the UFH return rail on the basis that it probably gives an earlier indication of where the floor temp is headed than waiting for the air temperature to change.

 

All that said, everything works perfectly fine as it is, so I'm not greatly motivated to add more complication or expense.

[Rob99]

I very much echo what a number of the others have said in that it's best to keep things simple. For my set up I have UFH downstairs and radiators upstairs. UFH has 8 zones. with 2 doubled up in larger rooms so 6 rooms/areas in total. My Loxone system controls the demand using the touch switch thermostats and then opens a zone valve for UFH or Rads as required using relays. The zone valves then trigger the boiler as would be the case in a normal heating set up. I essentially took the view that Loxone would replace the traditional time clock/programmer but with much greater control and configuration. I'm a Loxone partner so went with Loxone tree actuators on the manifold and AIR ones on the radiators as it made wiring simpler (ours was a refurb not a new build).

 

@jack is right, there have been some issues with Loxone actuators failing with broken components internally. They have a 2 year warranty but it's a hassle to have to send them back for them to be assessed and then a replacement sent out.

 

For clients now, I generally advise to go with a "standard" type heating set up and not use the Loxone actuators. It saves a huge amount of cost and, if you go with a heatmiser UFH control box (about £90 I think) then Loxone just has to trigger each zone demand and the heatmiser takes care of the valve opening and boiler firing. It means you can use readily available and cheaper 230V NC actuators.

 

The advantage is that, apart form Loxone triggering the demand for heat, everything else is familiar to heating engineers/plumbers and electricians so simple to maintain in future.

 

Hope that helps.

 

Edited October 1, 2021 by Rob99

[jack]

3 hours ago, joth said:

Automatic roof window opening at night time, for stack cooling, is probably the single biggest utility of the entire loxone install, somewhat to my surprise as I only added it as an afterthought. It's incredibly effective, and again I use the MVHR "outdoor temperature" sensor as a very reliable guide as to when stack venting will be useful to enable. (the MVHR "bypass status" would also be a good signal for this, as it ensures that the mvhr and heating/cooling are not in danger of fighting each other)

 

Presumably you have other windows open in the house to get the stack ventilation working? I've considered this (we have an electric roof window, although it isn't presently wired in), but we get insects in if we leave windows open, and I assume the stack ventilation won't work as well if the roof window is the only thing open.

 

I've considered getting insect screens to windows can be left open all night in summer.

[joth]

10 minutes ago, jack said:

 

Presumably you have other windows open in the house to get the stack ventilation working? I've considered this (we have an electric roof window, although it isn't presently wired in), but we get insects in if we leave windows open, and I assume the stack ventilation won't work as well if the roof window is the only thing open.

 

I've considered getting insect screens to windows can be left open all night in summer.

We have a skylight at the top of try vaulted ceiling over the hallway (3 story void) and a rooflight on the ground floor extension flat roof. I open the skylight to an increasing amount based on the difference between actual and target internal temperature, and when that's beyond 10% open I also open the downstairs rooflight. For whatever reason the skylight supports setting an exact % open  position whereas the rooflights are either 0 or 100%, hence this algorithm.

 

 

For bonus points I calculate an "overheating risk" based on tomorrow's forecast and whether we overheated in the last 18 hours, and if so set the overnight target one degree lower as a sort of cooling "boost" mode.

Finally, it all locks out closed if it's raining, rain forecast in the next hour, or if it's hotter outside than inside.

 

I tried to also make interlock so that the LED strips around rooflight won't come on when they're open, to reduce fly attraction, but I found in practice we didn't get flies in anyway this summer, fortunately. Fly screens would be the other solution!

 

 

 

[joth]

3 hours ago, Hilldes said:

 Thanks, that is what I'm now thinking based on Joth's post. I guess though, as soon as a manifold serves more than one zone then each circuit/loop on that manifold will need an actuator? 

Yeah exactly. We have 9 UFH loops, so I have 9 salus autobalancing actuators sat in a box in case I can ever be bothered to install.

I've modelled downstairs as 3 rooms with 3 Intelligent Room Controllers in loxone, but they all drive Call For Heat onto a single heating/cooling controller that drives relay for the downstairs zone call for heat  on the ashp controller.

Having 3 IRCs means I can have different cooling profiles for the areas under automatic rooflights, and also can set different target temps based on different schedules and occupancy per room. But that's just me tinkering in the loxone programmer because it's a bit addictive. From a systems point of view it's just one room stat calling for heat on one big ashp UFH zone. 

Edited October 1, 2021 by joth

[jack]

2 minutes ago, joth said:

But that's just me tinkering in the loxone programmer because it's a bit addictive. 

 

Isn't it though! It's been nearly 6 years since we installed our system (electrician did the wiring, I did the programming), and I still enjoy tinkering with it. I have quite a few ideas at the back of my head that I'll one day get around to implementing.

[joth]

5 minutes ago, jack said:

 

Isn't it though! It's been nearly 6 years since we installed our system (electrician did the wiring, I did the programming), and I still enjoy tinkering with it. I have quite a few ideas at the back of my head that I'll one day get around to implementing.

 

This summer was peak tinker, especially before lockdown eased. I think my wife was looking for "Loxone Widow's" support groups at one point.

 

 

 

 

[Hilldes]

4 hours ago, Rob99 said:

I very much echo what a number of the others have said in that it's best to keep things simple. For my set up I have UFH downstairs and radiators upstairs. UFH has 8 zones. with 2 doubled up in larger rooms so 6 rooms/areas in total. My Loxone system controls the demand using the touch switch thermostats and then opens a zone valve for UFH or Rads as required using relays. The zone valves then trigger the boiler as would be the case in a normal heating set up. I essentially took the view that Loxone would replace the traditional time clock/programmer but with much greater control and configuration. I'm a Loxone partner so went with Loxone tree actuators on the manifold and AIR ones on the radiators as it made wiring simpler (ours was a refurb not a new build).

 

@jack is right, there have been some issues with Loxone actuators failing with broken components internally. They have a 2 year warranty but it's a hassle to have to send them back for them to be assessed and then a replacement sent out.

 

For clients now, I generally advise to go with a "standard" type heating set up and not use the Loxone actuators. It saves a huge amount of cost and, if you go with a heatmiser UFH control box (about £90 I think) then Loxone just has to trigger each zone demand and the heatmiser takes care of the valve opening and boiler firing. It means you can use readily available and cheaper 230V NC actuators.

 

The advantage is that, apart form Loxone triggering the demand for heat, everything else is familiar to heating engineers/plumbers and electricians so simple to maintain in future.

 

Hope that helps.

 

Thanks @Rob99, that is great practical advice and much appreciated. I'll probably go down the route you suggest or even with no actuators initially as Joth has done (need to get the lighting scenes sorted first ?). I was not sure I could justify £1,900 on Loxone tree actuators.

[Dan F]

 

9 hours ago, jack said:

Mine is extremely simple. We have 8 loops downstairs, all run as a single zone. No UFH upstairs. Temperatures from a handful of cheap 1-wire temperature sensors upstairs and downstairs are averaged within Loxone and used to call for heat from the ASHP via a relay. I decide when it's heating season and switch the ASHP mode accordingly. I could automate this, but I only have to do it a couple of times a year, so it's no real effort.

 

We are implementing the same approach with Salus auto-balancing actactors.  Cooling is an issue though as our ASHP apparently doesn't have any way to "call for cooling", although I'll investigate this further once it's installed.  In the short-term, until I work out how to interface with the eBus protocol we'll probably just need to leave cooling control to the Vaillant controllers.

 

Couple of comments on your option 4:

- Do you really need to control UVC from Loxone.  Surely your ASHP/boiler will manage this by itself?  Or are you planning some interesting stuff with this?

- You can use 23 relay outputs for each actuator (if you really need all the zones), but you'll also need to call for heat too surely?  No good opening the actuators if you're not telling ASHP/boiler to turn on (unless you are seperlalty monitoring the temperature of a buffer tank and firing up ASHP/boiler based on this?)

 

Edited October 1, 2021 by Dan F

[Dan F]

11 hours ago, IanR said:

just circulate the UFH, without any heat/cool input in order to distribute solar gain,

 

That's an interesting idea!  I started out planning to control everything heating related from Loxone including the temperature of heating circuits etc, but then realised that the Vaillant controller already does all of this and it was a bit silly to reimplement this in Loxone. Circulating UFH without heat is one thing that the Vaillant controller can't do though!  It would also probably require some adjustments to our schematic which currenlty has a single circulation pump for UFH and MVHR with two zone valves, without a dedicated UFH pump.  

 

Interesting also that you are managing the buffer temperature with Loxone.   What ASHP/boiler are you using?  Does it's controls not support any of this, or what additonal value do you get from managing buffer temp?

 

Edited October 1, 2021 by Dan F

[IanR]

5 minutes ago, Dan F said:

That's an interesting idea! 

 

Borrowed from Jeremy. Makes more use of the Solar Gain, moving the energy to areas of the slab that do not receive the solar gain directly.

 

9 minutes ago, Dan F said:

Interesting also that you are managing the buffer temperature with Loxone.   What ASHP/boiler are you using? 

 

My initial setup did manage the cooling temp of the buffer, calculating the dew point from the current indoor air temp and humidity, and setting the cooling return temp to this. In practice I don't need to get the slab anywhere close the dew point to provide effective cooling, so I no longer change the buffer (cooling) return temp from 14°C. The heating temp of the buffer I've always left set by the ASHP controller.

 

But, rather than changing flow/return temps to the buffer, which I now leave as set by the ASHP controller, I get Loxone to enable/disable cooling and heating on the ASHP controller, so that it will only have one enabled at any one time.

I have a Nibe F2040-12 with SMO40 Controller and MODBUS comms unit.

[Dan F]

 

56 minutes ago, IanR said:

My initial setup did manage the cooling temp of the buffer, calculating the dew point from the current indoor air temp and humidity, and setting the cooling return temp to this. In practice I don't need to get the slab anywhere close the dew point to provide effective cooling, so I no longer change the buffer (cooling) return temp from 14°C. The heating temp of the buffer I've always left set by the ASHP controller.

Don't you run your MVHR HEX below dew point, or do you have a single circuit running both at 14C?

 

56 minutes ago, IanR said:

 

But, rather than changing flow/return temps to the buffer, which I now leave as set by the ASHP controller, I get Loxone to enable/disable cooling and heating on the ASHP controller, so that it will only have one enabled at any one time.

 

That makes sense.  So really, while you have the relays in place for the different pumps/valves,  the only thing you are currently doing from Loxone (aside from determining heating/cooling demand) that adds value on top of what the ASHP controls already does is the UFH circulation thing? 

 

[IanR]

2 hours ago, Dan F said:

Don't you run your MVHR HEX below dew point, or do you have a single circuit running both at 14C?

 

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.

 

2 hours ago, Dan F said:

So really, while you have the relays in place for the different pumps/valves,  the only thing you are currently doing from Loxone (aside from determining heating/cooling demand) that adds value on top of what the ASHP controls already does is the UFH circulation thing? 

 

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.

 

I hope to do a little more with it as currently I manually make a choice on whether it starts heating the house first thing in the morning, based upon forecast cloud level. If there is forecast clear or partially cloudy sky, I delay the buffer warming up until mid morning, to gives a chance for solar gain to do its job. But this means the temp dropping slightly below the target temp. If I don't do this I can often get a warm 200l buffer that then isn't used, since a couple of hours of winter sun pushes the temp up above target. I hope to automate this with a weather subscription.

 

That also reminds me of another subtle difference Loxone makes, which is to, during the heating season (Dec-Feb) to allow the house temp to go a couple of degrees over target, if that additional heat is via solar gain (ie without ASHP space heating). It seems no one in the family minds if the house is a little over-temp in the Winter, and if it is a couple of degrees high in the afternoon/evening, then even on an over-cast following day there won't be another call for heat probably until the following afternoon.

Edited October 1, 2021 by IanR

[joth]

7 hours ago, IanR said:

I hope to automate this with a weather subscription

I've got a weatherflow tempest, and the loxberry integration for it works very well providing weather forecast off of the tempest cloud API, as well as live readings from the weather station itself. No recurring charges

 

 

Very helpful info on the rest of your setup! I had intended to circulate UFH in this way (also copied the idea from Jeremy) but so far haven't found it necessary, as the UFH is only on the ground floor and that's almost all open plan and solar gains very naturally convect through the building anyway. What I really could use is a way to redistribute overheating from upstairs back down into the slab, but that would require another (water to water) heat pump

[Hilldes]

12 hours ago, Dan F said:

 

 

We are implementing the same approach with Salus auto-balancing actactors.  Cooling is an issue though as our ASHP apparently doesn't have any way to "call for cooling", although I'll investigate this further once it's installed.  In the short-term, until I work out how to interface with the eBus protocol we'll probably just need to leave cooling control to the Vaillant controllers.

 

Couple of comments on your option 4:

- Do you really need to control UVC from Loxone.  Surely your ASHP/boiler will manage this by itself?  Or are you planning some interesting stuff with this?

- You can use 23 relay outputs for each actuator (if you really need all the zones), but you'll also need to call for heat too surely?  No good opening the actuators if you're not telling ASHP/boiler to turn on (unless you are seperlalty monitoring the temperature of a buffer tank and firing up ASHP/boiler based on this?)

 

I think I must be the only member of Buildhub that does not have an ASHP - I really wanted to go down that route but my time limitation and cost prohibited for now, but a potential retrofit. Instead I have a new technology that derives energy from rotting vegetation that has lied dormant for millions of years ?. On the call for heat of the heat source that will be handled by the Wunda wiring centre for options that use this (it will operate the relevant zone valve, manifold pump and call for heat). In the full Loxone control option, the zone valves, UFH pump and call for heat will all be fed from Loxon relays.