Heating with Danfoss and Secure thermostat

[Milos797 2]

Hi guys,

please excuse me, but I couldn't find the answer for my question.

I am thinking to do the heating in our house. The current situation is:

we had a gaz boiler, in the living room we have normal controller which we use basically to switch on and off the heating. Then, in some rooms our radiators are closed, in some open (depends where we are). This is standard I think.

Now the question is, I want to use the Danfoss Living connect, so what else do i need?

Do I need the set of secure srt322 or do I only need SSR303 to turn on and off the boiler when one of the danfoss will ask for heat?

And what is then the point of the SRT321? Is that basicly just a device, which can control the temperature in one room? The way I see it, if I have in one room danfoss and fibaro motion senzor, I can control the room trough the system right?

Thanks a lot for help with this.

[j.nowacki 5]

You can use Danfoss devices only, but they do not provide any feedback to the system - you will not be able to tell if it is on or off. External thermostats allows you to set temperature and they control connected relay based on that - you can use one to toggle state of switch which controls boiler but only basing on temperature in one room. I think the best option here is to use ordinary electrovalves for each radiator (or Danfoss devices, but they can cause some problems when there are more than a few and 15 is max in one installation) controlled by Relay Switch and integrated by Heating Panel. Then create one scene that will gather state of all valves and basing on that information will control boiler.

[Milos797 2]

You can use Danfoss devices only, but they do not provide any feedback to the system - you will not be able to tell if it is on or off. External thermostats allows you to set temperature and they control connected relay based on that - you can use one to toggle state of switch which controls boiler but only basing on temperature in one room. I think the best option here is to use ordinary electrovalves for each radiator (or Danfoss devices, but they can cause some problems when there are more than a few and 15 is max in one installation) controlled by Relay Switch and integrated by Heating Panel. Then create one scene that will gather state of all valves and basing on that information will control boiler.

Thanks. But I can not really imagine how it is gonna look like. where will the realy switch go? there is not a lot of space to gide it behind the valves right?

And with the danfoss, so they are not sending any info about what temperature are they set up on or something?

[martijnt 3]

You will need to use more than just the Danfoss thermostatic radiator valves.

With only the Danfoss valves, all you can do is "open" or "close" the radiator based on the configured (desired) room temperature compared to the actual (real) temperature in the room. You cannot turn your central heating unit or gas burner on or off with that.

You can try to quickly change the configured (desired) temperature in a room when your motion sensor detects that someone is in the room, but because the Danfoss valves are battery-powered they do not immediately receive the "push" of the new configured (desired) temperature - instead you have to wait for the Danfoss valve to connect to the Fibaro HomeCenter (configured with the "wakeup interval") before the new configured (desired) temperature will be received by the Danfoss valve. So there will be a delay between someone entering a room and the radiator valve opening *if* the room is too cold... And you will still not be able to turn on your central heating unit.

What you will need to ADD to your configuration is:

- A Horstmann / Secure room thermostat, for EVERY room you want to be able to control individually ("HRT4-ZW")

- A Horstmann / Secure "actuator" to go near your central heating unit ("HRT4 ASR-ZW"). You need only 1 of these.

With that combination of equipment you will be able to:

- turn on your central heating unit whenever ONE of the rooms is too cold.

- keep your central heating unit "on" as long as one of the rooms is too cold.

- continue to use your existing (traditional) room thermostat in for example your lounge

- control the configured (desired) temperature on a per-room basis using the Horstmann / Secure room thermostat that you added in each room

- there will STILL be the delay before the radiator valve actually "opens" because the radiator valve is still a battery operated device and does not communicate with the Fibaro HomeCenter all the time to save battery

If you want to be able to INSTANTLY turn on the central heating unit AND send heat to the radiator in the room you will need to:

- NOT use the Danfoss battery operated valves

- NOT use *any* battery operated radiator valve, really...

- Use for example the Fibaro motion sensor to sense that someone is in the room

- Use for example the Fibaro motion sensor to measure the temperature. OR use the Horstmann / Secure room thermostat to measure the temperature AND allow the temperature to be changed from within the room...

- Use a mains-powered unit like for example the Danfoss AMZ112 combined with a Horstmann / Secure "actuator" ("HRT4 ASR-ZW") to control it to create a separate "heating zone" for just one room

- Use a Horstmann / Secure "actuator" ("HRT4 ASR-ZW") to turn the main central heating unit / gas burner on and off

In the last setup, the Fibaro motion / temperature sensor OR the Fibaro motion sensor combined with the Horstmann / Secure room thermostat will control the temperature in the room and will decide when the central heating unit is turned on and when the valve for the separate heating zone is "opened" (the AMZ112). In this scenario you do NOT use *any* valve on your radiator anymore...

I guess your best solution depends on your budget and the physical infrastructure of your home. You need quite some space as well as regular 230Volt power sockets to fit the AMZ112 and the HRT4 ASR-ZW in...

Personally I am using the Danfoss valves with the room thermostats and the HRT4 ASR-ZW, because life in my household typically evolves around a pattern that I can predict. It hardly ever happens that one of my children is at home sick instead of being in school. So I very rarely have a need to instantly adjust the temperature in a room.

oooh.... regardless of what you will be using, you will need to program some LUA code in the HomeCenter...

I hope this helps...

[blawre0000 1]

Hi

Have a look at this. I have this working (with some mods) and it works well.

Please login or register to see this link.

Brian

[Dalle1985 16]

The danfoss thermostat is designed for a system where you have a constant hot water supply. The thermostat will measure the temperature where it is located and then constantly throttle the radiator to keep a constant temperature. If you want to use an external thermostat, you should be using an on/off valve which opens with the boiler relay. Then when the room is hot enough, it will turn off the heater and close the valve.

Both have advantages and disadvantages. The danfoss valve will use less energy as it operates the radiatio at it's most efficient (if the radiator is sized correctly) but you can't use an external meassuring source.

The external thermostat is more flexible as you can position it as you want, but the on off regulating doesn't transfer the heat as efficiently in the radiator. This system is better suited for in floor heating, if you have a return temperature throttle valve.

[Milos797 2]

Guys thanks a lot for your help.

Martijnt you explained it great. Only I have few more questions.

With the first option, If I have lets say

3 rooms,

3x motion sensor,

3x danfoss and

1x HRT4 ZW

1x HRT4 ASR-ZW,

that means I see temperature in every room (motion senzor). And lets say I am in the room one. The sensor see me, check the temperature. If the temperature in room one is lower then lets say 22 degrees, it will send the command to the danfoss to set higher temperature (only in that room, lets say that in every other room the danfoss will stay on 18 degrees) and send the command to the HRT4 ASR-ZW to turn the boiler on.

When the temperature in the room will be 22, fibaro will send the signal to the HRT4 ASR-ZW to turn boiler off.

I mean, why do i need horsmann for every room, if I see the temperature thanks to motion sensor. The only point is to send the command to the "actuator" to turn boiler on? Cant this be done with some scenes? Sorry for this question, but I live in house with 8 rooms and usualy we use only 3 of them, so I would like to set it up somehow.

What kind of delay are we talking about? is that in seconds or in minutes?

The second option seems to be much simplier but there are two things which makes it worst. First one is that it wont be anymore NON INVASIVE instalation. That is important.

And the second point, the price. I have the feeling this will be even less affordable

Please login or register to see this image.

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About the LUA. If I will be trying to do this with HCL, there is not much I can do I guess? Do you thing would this be possible to do with the scenes? Or the scenes will just allow me to turn it on in every room and thats it?

Thanks a lot

[Guest berga_s]

Take care to this video where it looks like that the multizone with the secure Thermostaat should not work when 1 of the thermostats doenst need heat anymore, it will turn of the boiler actuator, without checking if the other one still needs heat...

[martijnt 3]

Take care to this video where it looks like that the multizone with the secure Thermostaat should not work when 1 of the thermostats doenst need heat anymore, it will turn of the boiler actuator, without checking if the other one still needs heat...

You can completely ignore that because it is based on an incorrect setup. This is what happens when you link multiple thermostats directly to the boiler actuator - but that is not what the equipment was designed for, and that is why that does not work...

In my previous (rather long) post, I mentioned that you will have to do some LUA coding. The piece you have to code is the intelligence of how to handle requests for heat from multiple zones and how to handle the signal where one of the rooms no longer needs more heat.

The Fibaro "Heating Panel" doe snot handle this for you either. But a little scene will do the trick just fine.

Martijn.

[ Added: 2014-10-05, 09:15 ]

I mean, why do I need Horstmann for every room, if I see the temperature thanks to motion sensor. The only point is to send the command to the "actuator" to turn boiler on?

If you only ever want to heat the room up to a fixed pre-determined temperature that you have set in your code, then you don't need the Horstmann room thermostat. But if you want to be able to manually override the desired temperature that you have set in your code, then you will need a way to do that. That is where the Horstmann room thermostat comes in handy.

You could argue that the Danfoss radiator valve also allows you to modify the desired temperature. That is true - but. In my opinion (and a lot of others agree) the Danfoss radiator valve is a pain in the neck to handle. You really do not want to use the controls on that thing. Especially not in the positions where you will probably have the valve located (like low to the floor or difficult to get to corner).

What kind of delay are we talking about? is that in seconds or in minutes?

The delay is determined by the "Wake up interval (s)" parameter that you can configure in the Fibaro interface. The manual of the Danfoss valve states to not set this lower than 5 minutes (300 seconds) because it would drain the batteries... I have one of mine set to 300 seconds and the batteries have been going for about a year and a half now. They are still half full... So I guess the battery drain does depend on the z-wave signal quality in your house.

About the LUA. If I will be trying to do this with HCL, there is not much I can do I guess? Do you thing would this be possible to do with the scenes? Or the scenes will just allow me to turn it on in every room and that's it?

Unfortunately I cannot tell you whether or not this will work properly with a HCL - I only have a HC2. I have also never tried to put the LUA together using the visual blocks - I just went straight into LUA code. But I am no expert on this front.

Martijn.

[ewenjc 0]

I have a similar question. Not sure if I should post as a separate thread.

Moved to separate thread.

[HomeSystem.sk 69]

Hey Martjin.

I got a bit deeper to this, so I can add some and I have one more question.

First at all - danfoss radiator valves are good for flats, where you are not able to turn the heating off but you are charged for the heat from radiators... That's OK, I tested it and it works with scenes.

This week I start testing Horseman SRT321. First at all, it doesn't do much. For price of 80€ you can buy tablet, hang it on the wall instead of termostat and use it as controller for home and heating.

But...

The termostat does one thing - it controls the temperature easy. So you set it to 25, it turns on the relay, if the temperature became 25, it turns it off and on again if the temp jump just under 25. I guess you can do this without termostat with scenes and variables, but it would be tricky. So this is one thing where the termostat comes handy. But basically we can do this without it with the tablet right?

But I came to one problem. What if the HC fall, became not responsible or get stuck... How do you control your heating then?

The answer for sure is, that with the tablet option you are basically stuck. There is no way how to switch the relay without system. And here the termostat becomes really handy. If you have associations running, even without system the termostat will turn on the relay. That is great.

But I was thinking, could you use normal (not z wave) termostat, which would be an 0 degrees all the time (closed) and have relay connected to boiler somehow. Then control the heating with the tablet mounted on the wall. And in case of HC problem use termostat to control the heating. I mean, the HC get stuck, so the relay is open. Is there any way of connecting the writes so the old termostat will work?

And I have one issue, I tested it on HCL and HC2, but I can not chose SRT321 temperature as a room temperature and so I can not use this termostat with heating panel. Don't you know where can be the problem?

Thanks

[HomeSystem.sk 69]

oooh.... regardless of what you will be using, you will need to program some LUA code in the HomeCenter...

 

Hey Martjin,

 

I am back on this topic as I am dealing with this with new customer. By program some LUA code you mean program that if I change the temperature on thermostat it will automaticly change the temperature on danfoss LC13? Because I am testing this, via android app and heating panel it works good, I change the temperature, it changes the set temperature on Secure and on Danfoss as well. But if I change temperature on termostat manually, it is not changing the temperature on danfoss. Associations doesnt work with this. Scenes does, but honestly it will need at least 15 scenes for every room (if termostat =21 than danfoss 21...). So my question, is this the part you need to code, that you make one LUa which will say if secure = 21 then danfoss = 21 elseif secure = 22 then danfoss = 22...? Or what exactly is the Lua code necesarry for?