Hello,
I've alreday have de thermal solar controler but I would like to relace it by a selfmade one with more option (collecting datas, web server, remote management).
But I need some extend to your project and I woud lilke if it is possible with the current controller, and not too much changement as I'm a newbie.
1 )My water tanks as 2 heater entries : one from se solar planed on from boiler.
So I would like to known if is possible to to add "Time controlled back-up heating ":
- a thermal sensor on the upper part of the water tank
- add an other relay to drive the pump of the boiler controlled by a Timer
2) Controll a Circulation pumps
- need a relay to active the pump
- need a timer (I jsut what th epump to turn on the morning)
- need a thermal sensor on return of the pump to know if it is usefull to activate it
3) Add a vacation mode
- when away for long time, the pumps is activate at night to cold the water tank
Re: Solar hot water controller - extensions
Concerning the Solar panel protection I don't know if it is already implement in the software, but the logic should looks like :
If the temperature in the storage tank reaches the set value 'Active from storage tank x°C' (something like “storage tank max” temperature – 7°C), Activate the Solar panel protection.
Then the solar circuit pump is switched off.
Since the solar circuit does not release heat via the storage tank, the solar panel temperature is automatically increased. When the set Solar Panel temperature ('SP') is exceeded, the solar circuit pump is switched on again and id possible (PWM ?) with low speed.
Only when the temperature on the Solar panel sensor has decreased by 10 Kelvin of the set value ('SP') is the solar circuit pump switch off again.
Re: Solar hot water controller - extensions
Hi Nitocris,
There is some documentation for a SHW controll and monitoring system up on this site: http://openenergymonitor.org/emon/solarhotwater. Hope this is useful.
Good luck wiht your project, Glyn.
Re: Solar hot water controller - extensions
My questions are precisely on any possible extension of this project.
Re: Solar hot water controller - extensions
Hello Nitocris
Yes you can extend it as much as you want, if your familiar with the arduino its just a matter of adding the sensors and actuators as you require for your project. My documentation covers what I needed but please by all means extend on this.
As for protection, I implemented both low temperature protection and high tempertature protection. If the water gets below 5 degrees C the pump turns on to stop the water from freezing. (5C just to be safe as cold wheather can still force it lower). If the tank is already at 80C plus then the pump will not turn on so that we prevent overheating or even boiling of the cylinder. I think I explained all this and provided software source code in the documentation like that Glyn provided so please have a look there.
Let me know how you get on with building it.
Trystan
Re: Solar hot water controller - extensions
Hi Guys,
With regards to the SHW http://openenergymonitor.org/emon/solarhotwater
I'd like to understand something, if it's controlling the pump, is the relay usually open or usually closed, I ask because say something happens the the emontx like it's power get's dropped, I would still like the pump to run, meaning that only when the water delivery is colder then the relay should break the current