SOLAR WATER HEATING CONTROL

[uruguay]

Dear all,

 

I am finding plenty of Customers using solar powered water heating systems at home (e.g. http://www.solarpanelsplus.com/residential/solar-space-heating/). I want to install one myself to play and have it fully integrated to Control4.

 

These systems bring a stand alone controller which receives information from 3-4 temperature sensors and control a few pumps, an electrical resistive load, among not too many more actions.

 

I would like to replace this controller by Control4 HCs, C4 panelized or CA individual relays, etc.

 

And what I´m finding more challenging is to identify thermostat that can work in the 45ºC to 105ºC temperature range.

 

Any clue? Any idea of existing drivers / compatible HW?

 

Thanks to all in advance.

 

Kind regards

 

Antonio.

[CFUG]

Short response- this is no where near the right application for Control4.  It is not hard to find a temperature controller for that range- Omron, Watlow, Omega, Red Lion all offer PID controllers that will hold a T to a gnat's ass.  Seems strange to chuck the dedicated controller in favor of something home automation-grade...

[uruguay]

Dear Guru. Thank you so much for the fast response.

 

I have to accept your argument regarding the reliability of the controlling system for the solar heating system. But, as far as I see my customers comments, the one major concern is to be able to know how well is doing the solar system (what temperature is being generated, what amount of heat reserve they have, etc.), without the need of going to the boiler room.

 

For what, either we can find the way to connect the thermostats to the HC, or the solar system controller to the HC (either controlling the system or just monitoring it).

 

For what, if there are no thermostats that we can integrate and that can work in that range, which controllers could be drived into the HC to get information and eventually shoot scenes (e.g. send an SMS to the house owner that there is not enough heat, or too much, etc.; nobody wants to run out of hot water when arriving home with wet feet, right?).

 

Kind regards

 

Antonio.

[CFUG]

Let me give an example.  The PV system I will be installing soon will have at least two standalone information centers.  One will come from the inverters themselves and the other will be via web and contain aggregate information from those inverters plus the grid.  I have, however, elected to bring some information into Control4 in the form of I-draw and V from select circuits including the PV array.  This kind of information cannot be collected directly by existing Control4 goods, one must utilize purpose-specific instrumentation.  I need to buy this.

 

Think about what goes on inside a typical high-tech temperature controller such as one designed for a hot-water delivery system.  The device maintaining a setpoint receives command either in the form of 0-5VDC or 4-20mA or a TC or a RTD.  How about the pump?  Variable speed drive requires a command signal.  What C4 device natively does this?  You will need to buy this.  I won't even get into the aspects of switching a high V component such as a back-up heating element.  When all is said and done, you will have recreated the wheel.

 

You still want to use Control4? Take for example a CA Contact Sensor.  That device's T sensor is good only to 70 degC.  You can't even use that!  Control4 has not the capability to read a voltage (aside from a contact closure situation), current (aside from a C4 outlet switch) or resistive value (aside from a thermostat) directly.  If it were me, I would select a dedicated Solar HW controller with some form of communication such as RS 232/485 and hire someone to write a driver for Control4.  The pool people use dedicated controllers all day long here in the USA...

 

 

That's my long response.  BTW, I'm not a "guru", I just play one on TV.

[alanchow]

We handle this in a slightly different way.  Rather then a small scale solar HWC we utilise residential solar systems with Control4 to manage whole home energy management.  If for example high PV output is detected whilst current detected power usage is low we transfer that energy into the HWC rather than feed it back to the uility.

[CFUG]

^That's very smart. 

 

Electric HWH (H as in Heater) in CA, USA would be like slitting your own throat.  I'm sure there are those who do use Electric tanks here...