Fibaro controlling 3-way valve for heating system

[Lauri 6]

Hello, I'm trying to figure out a good scene to adjust the water temperature inside the underfloor heating system. There is 2 different heating sources - gshp and regular heating oven for firewood. This way the temperature that reaches the house might be different from 40C to 80C depends on which heating source is working.

Now there is 3way valve which mixes the temperature for the floors. Water temperature has to be always higher than 25C and never exceed 38C. I have connected roller shutter module to the 3-way valve motor, and it seems to work very good. But how can I make such scene, where HC2 measures outside temperature and also the water temperature in the pipe going to the floor heating?

The point is - IF temperature outside is 20+ degrees, then water must always be 25C; If temperature outside is +10C then water must be 28C and so on:

Does anyone have a good idea how to do this?

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[Krikroff 199]

Lauri, you can do this easily with LUA code, the magic weapon is "pseudo collection" to create a "Températures Map" like that:

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if your sensor return 17°, temperatureMap returns the associated value 25°

is that it responds to your need?

[Lauri 6]

The roller shutter module has to open/close the 3-way valve. How does HC2 know what position roller shutter has to have if outside temperature is -5C to keep water temperature according the table?

[Krikroff 199]

add other key/value pair in the map: -5 -> 32, -6 -> 33 etc. put all you want in this map (table).

add global variable lastTargetTemperature to maintain the last temperature in HC2 system and available in all your scene for all your needs...

add other local variable currentWaterTemp to compare with targetTemperature :

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After this is a reflection on a chain condition ...

[Lauri 6]

Hello, I havent had chance to try this out yet, but I have to very soon.

I do not understand one thing, does HC2 recognize HEAT and COOL commands then? If I use this code, how HC2 knows when he has to turn roller shutter to different position.

And if it turns the 3-way valve, does it closes it completely if needed to cool, or just step by step until water temperature begins to drop?

Lua logic is not yet my friend, but I'm getting it more and more..

Many thanks!

[ Added: 2013-08-27, 09:09 ]

Hello again

I made a little drawing:

Goal is to get TEMP B between +25...+37 according to the outside temperature. BUT TEMP C can be very different, from +30.....+80 degrees, so roller shutter has to monitor TEMP B and TEMP A and it has to open-close 3way valve to rise or lower the TEMP B value.

Lauri

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