List of available Solar Controllers - and your 2 cents

[Mike vonB]

Just retired from the AF after 26 yrs and moved to Roseville CA, getting close to pulling the trigger on a roof mounted solar system - yippee! So what do I have to choose from in the way of controllers? Just to start off the list:

Pentair
- SunTouch
- others?
Hayward
- OnCommand
- GL-235
- others?
Other brands/models?

Feel free to chime in with your positive 2 cents on your system, and if you've always had it from the beginning.

 

[jblizzle]

Or any of the full automation systems, that could add SWG, digital timer and valve control.

The Pentair sun touch does seem to have some nice features though.

 

[Isaac-1]

Mine is the Hayward Aquasolar AQ-SOL-TC which includes a number of features that are not on the basic GL-235 like digital temperature display, built in timer, etc. Overall I have been happy with it, even though I did have to replace one due to lightning zap (lost other stuff including a TV from the same event), if I had to do a bare fresh install I would probably go with the Pentair Suntouch though. The AQ-SOL-TC and the Suntouch have a lot of features in common, but the Suntouch appears to be a much more advanced design, in general terms the Suntouch is a computerized controller with a relatively large LCD display and buttons for front panel programming, by comparison the AQ-SOL-TC is more electronic / electro-mechanical in nature using hardware jumpers, knob, switches, and a mechanical timer.

Ike

 

[Mike vonB]

I may just be a solar newb, or over/under thinking this, but could I get some sort of a air temperature sensor from Radio Shack to open the valve when hot enough, and close it once it cools down? Add the appropriate check valves and plumbing and save a few bucks?

 

[Isaac-1]

Air temperature is not the issue, the issue is the comparison of the water temperature with the available solar heat at the solar panel location. This means that solar heat being available depends on a number of factors, not only if the sun is out, but also how much heat at the panels may be getting lost to wind cooling, etc.

Picture a situation like this, a calm spring afternoon where the water temperature is 70 degrees, the outdoor air temperature is in the low 60's and the sun is shining, just like the roof a black car on a day like this the panels will be much warmer than ambient, and also warmer than the water. The solar controller would sense that panels being at least X (usually 2-3) degrees warmer than the water and divert flow through them and therefore warming the pool.

Now picture that the wind starts blowing at 10-15 mph, this cool air crossing the panels cools them down equal to or below the water temperature, which lets say is 71 at this point, the solar controller turns the flow to the panels off and waits for the wind to stop and the panels to warm up again. Repeat.... (the same thing would happen with clouds, afternoon rain showers, etc.)

Ike


p.s. the better solar controller have a built in delay feature to keep short cycling of the pump motor from occurring.

Also remember that you can get a basic GL-235 without actuators for somewhere around $150-$175 online with a bit of shopping, this includes the housing, and the controller, and complete kits with valve, an actuator, and a pair of sensors for about $250 (search: GLC-1P or GLC-2P solar) for the kit