PID algorithm

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dicdastardli
Posts: 3
Joined: 06 Jan 2015, 15:52

Re: PID algorithm

Post by dicdastardli » 13 Jan 2015, 08:55

Hi Gaby-netatmo,

after almost 3 weeks my thermostat still doesn't propose advanced algorithm.
With my old thermostat I had the PID algorithm active and i had more comfortable house temperature.
Is there any issue in determining the thermal behaviour of my heating system? My serial is J062974.

Thank you

Gaby-Netatmo
Posts: 309
Joined: 07 Jan 2014, 11:47

Re: PID algorithm

Post by Gaby-Netatmo » 13 Jan 2015, 11:03

Hi dicdastardli,
After analyzing the behavior of you thermostat Netatmo, we have noticed that the measured temperature increases slowly.
This is mainly due to the high heating inertia in your house.
It can also be due to a low water temperature in your heating system.
In these cases, we do not generally propose the advanced algorithm (PID) because the regulation is considered as good enough in the hysteresis mode.

However, if you wish we can force the activation of the PID parameters.
Thank you
Gaby Netatmo

dicdastardli
Posts: 3
Joined: 06 Jan 2015, 15:52

Re: PID algorithm

Post by dicdastardli » 13 Jan 2015, 11:09

Gaby-Netatmo wrote:Hi dicdastardli,
However, if you wish we can force the activation of the PID parameters.
Thank you
Gaby Netatmo
Hello Gaby-Netatmo,

yes please, can you force the PID activation? I would like to try it, and then decide what is better for the room comfort.

Thank you

wonderiuy
Posts: 26
Joined: 21 Nov 2014, 09:58

Re: PID algorithm

Post by wonderiuy » 13 Jan 2015, 11:44

The problem is that Netatmo and its PID algorithm doesn't know the construction material of your house (bricks or concrete, or wood, etc) and the kind of heating radiator (steel or aluminium): these two factors are really important and can lead to a great waste of money if you use the wrong algorithm.
PLEASE netatmo, add a feature that let user specify construction material and kind of heating radiator and then apply the right hysteresys or PID (or multiple PID) accordingly.
PLEASE add also a user setting of water temperature (waht he gets from boiler) Thank you

runemann
Posts: 59
Joined: 16 Oct 2014, 14:58

Re: PID algorithm

Post by runemann » 15 Jan 2015, 12:06

The empirical data (the recorded input producing the PID) in effect takes into account the materials and all other things already, implicitly that is, so I wonder if that is a good way to explore really.

FYI I have PID numbers ready for me to use, but I find that setting the programs manually does the trick all right. When living with the thermostat for a while, logging on the the web page (or app) and observing the heating over some days/weeks, I can for instance see for myself how many degrees the temperature increases per hour, say 1 to 2 degrees in my case. Of course this will wary if the outside temperature is -15 degrees or +5 or whatever. The point is that I can rather easily set up a plan that make sure that everything works well, based on how I observe the heating works.

I can see that the thermostat follows my plan perfectly, with absolutely no deviation or weird things going on. I have for instance never experienced coming home to a cold house or the heating going through the root at night or something (I read some reviews of the Nest thermostat, where people observed such things).

The PID does the same automatically yes, but I fear that "spurious data" or changing data over time (winter/summer) or something might make the PID program a bit volatile or strangely behavioured. Seems to me that some of the problems people have with the thermostat going ON or OFF at odd periods, could be attributed to such spurious data.

So - my point is that living with the thermostat for a while, looking at the daily temperature charts and observing how the heating changes according to the boiler being ON or OFF, in effect gives me a nice and sensible background to set up weekly schedule using the "hysteresis" algorithm. I can also easily account for heating increasing slower at winter etc. My schedules work perfectly, and also pretty efficient I believe (I try to minimize the time the heating is ON)

Kpow99
Posts: 17
Joined: 04 Jan 2015, 13:45

Re: PID algorithm

Post by Kpow99 » 17 Jan 2015, 17:47

Hi

I need to understand how this is supposed to work as I just don't get the logic!?!?

This morning my temp was set for 18.5c and it got to that temp then the system decided that at 10am it was going to turn the temp up to 19c with the "Program Anticipation" for the next set point time of 4pm!!!

Why is it anticipating 6 hours in advance??? I don't understand why it is going up to that temp so far in advance, I don't want the house at 19c now and all day so I've had to change the evening temp down to 18.5c rather than a 6 hour manual override.

I'd like to use the algorithm and understand it can take a couple of weeks to set itself up properly but not at the expense of turning the heating up unnecessarily. I'll have to turn it off if this is the case as it will increase my fuel costs rather than save it.

I have attached pics so you can see what it has done.

Just seems crazy that it is turning up 6 hours in advance!!! Anyone else had the same problem? Netatmo support can you explain?

Front end of the app...
Image

The program schedule showing that next temp change is at 16:00.
Image

And the actual program showing the previous temp, current temp and the call for the boiler...
Image

Gaby-Netatmo
Posts: 309
Joined: 07 Jan 2014, 11:47

Re: PID algorithm

Post by Gaby-Netatmo » 19 Jan 2015, 09:58

Hi Kpow99,
Can you give us the serial number or the MAC adress of your Thermostat so we can study your case.
Thank you
Gaby-Netatmo

Kpow99
Posts: 17
Joined: 04 Jan 2015, 13:45

Re: PID algorithm

Post by Kpow99 » 19 Jan 2015, 13:50

Hi it is j065568

Thanks

Gaby-Netatmo
Posts: 309
Joined: 07 Jan 2014, 11:47

Re: PID algorithm

Post by Gaby-Netatmo » 19 Jan 2015, 14:56

Hi Kpow99,
We have modified the prediction parameters on your Thermostat.
Thank you.
Gaby-Netatmo

wonderiuy
Posts: 26
Joined: 21 Nov 2014, 09:58

Re: PID algorithm

Post by wonderiuy » 19 Jan 2015, 23:11

Is that all? No further explanation?

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