Tasmota Thermostat enhancement

[Peter]

Hi,

I'm investigating the use for Tasmota Thermostat feature. What I would like extra is to use outdoor temperature to adjust the heating depends on outside temperature. For example when outside is colder then there must be more heating.

That's why my initial idea is to add some delay between Cycle times. And this delay will be dependent on outside temperature.  If outside temperature is higher then delay is longer. Maybe Javier could tell if this is possible and how to do it?

Does this sounds reasonable? Or there is already some more easy solution? Or do I use some external sw like Domoticz or something else? And in this case what would be preferred if I only need little more smarter thermostat functionality.

I'm still investigating this smart home area that's why my thinking could be wrong.

Thanks for the response in advance.

[Philip Knowles]

In theory you could another device which is reading the external temperature and use a rule in that to send a

cmnd/Tasmota_Name/TIMEPICYCLESET %var1%

where you vary var1 according to the temperature. This might work

on tele-ds18b20#Temperature do var1 30 endon

on tele-ds18b20#Temperature < 10 do var1 15 endon

on tele-ds18b20#Temperature  > 25 do var1 60 endon

on var1#state do websend [x.x.x.x] TIMEPICYCLESET %var1% endon

 

Regards

 

Phil K

 

Sent from Mail for Windows

--
You received this message because you are subscribed to the Google Groups "TasmotaUsers" group.
To unsubscribe from this group and stop receiving emails from it, send an email to sonoffusers...@googlegroups.com.
To view this discussion on the web, visit https://groups.google.com/d/msgid/sonoffusers/9fe05fc6-525e-471b-9464-2ce084d75688n%40googlegroups.com.

 

[Peter]

I'm not sure if changing TIMEPICYCLESET would do any difference. In this case the proportional ratio for heating ON/OFF would still be the same.

Like this image is showing when measured temperature is the same as set temperature, the ratio is 50%. But this ratio must be different if outside is +5° or -10. That's why my idea is to add delay after each cycle.

But maybe I just don't understand heating. I only know what I currently use doesn't work as intended.

[Philip Knowles]

I was basing it on this

Cycle time~

Depending on the heating system, the cycle time (PMW period) can be adapted. Very slow systems (high time constants) such as heating floor systems might need higher values (default value is 30 minutes), faster systems might need smaller cycle times. Below the command to adapt the cycle time can be found:

cmnd/Tasmota_Name/TIMEPICYCLESET 30

If the outside temperature is low it will make the heating system slower to react. If the outside temperature is high the system will react faster. The issue is to do with ‘integral wind up’. If the system is slow to react the controller may not reach the set point, keep the heating on too long and overshoot – if it reacts too quickly the system will ‘hunt’ as it heats up quickly and overshoots.

That’s purely from a PID point of view but a lot depends on the dynamics of your system.

 

Regards

 

Phil K

 

Sent from Mail for Windows

 

--

You received this message because you are subscribed to the Google Groups "TasmotaUsers" group.
To unsubscribe from this group and stop receiving emails from it, send an email to sonoffusers...@googlegroups.com.

To view this discussion on the web, visit https://groups.google.com/d/msgid/sonoffusers/c8512930-bf08-45bc-8655-ec81e0b68a38n%40googlegroups.com.