Solar Panel Plumbing and Valves

[xrabbi]

I am installing a solar panel array (Heliocol) on a patio roof. As shown in the picture below, the feed and return lines come down from the roof along a vertical post, then continue into the ground where they run horizontally about 25' before turning straight upwards to the pool equipment pad in the pool house. Where is the correct place to install the 3-way solar valve and check valve if I want automatic/gravity drain down of water in the solar panels? A traditional installation (like second drawing below) has the valves at the equipment pad but would this work in my up-down-up pipe run? Should the valves better be on the vertical post going up to the roof? (And what is the point of the drain-down solar valve if the water then runs straight into a check valve?) Any thoughts/guidance appreciated.

 

[ajw22]

@mas985 may have ideas for that setup.

 

[mas985]

I am installing a solar panel array (Heliocol) on a patio roof. As shown in the picture below, the feed and return lines come down from the roof along a vertical post, then continue into the ground where they run horizontally about 25' before turning straight upwards to the pool equipment pad in the pool house.

I would bury the horizontal pipe below the freeze line for your area as that portion of pipe may not fully drain since it will be below pool water level. Of course you can always winterize the lines anyway.

Where is the correct place to install the 3-way solar valve and check valve if I want automatic/gravity drain down of water in the solar panels?

Fully draining the the solar panels and plumbing does not depend on the valve locations. It only depends on the height of the panels and solar plumbing relative to the pool water level. It is also dependent on any local low points where water can settle such as the horizontal run to the equipment shed. Ideally, you want downward sloping pipe runs without any local high spots but that is likely to be impossible near the equipment shed as that pipe will need to rise to pump level.

A traditional installation (like second drawing below) has the valves at the equipment pad but would this work in my up-down-up pipe run?

Yes

Should the valves better be on the vertical post going up to the roof? (And what is the point of the drain-down solar valve if the water then runs straight into a check valve?) Any thoughts/guidance appreciated.

No, it would not improve draining and would only add head loss for the non-solar run time.

 

[xrabbi]

Thanks very much. I'm posting below picture of equipment pad inside the pump house. As you can see, last year the installer of our salt cell tried to anticipate the solar addition and added the 3-way valve plus the two vertical capped pipes (one for solar feed, one for solar return) to the return line between filter and salt cell (which is disconnected at the moment). Is that 3-way valve useable where it is currenty installed or do I need put a check valve in somewhere to prevent backflow to the cartridge filter? I don't think it is a proper solar 3-way valve (though I have one). Any guidance on the proper plumbing appreciated!

 

[xrabbi]

See below picture of equipment pad inside the pump house. When our SWG was installed last year, the installer tried to anticipate a solar addition and added the 3-way valve plus the two vertical capped pipes (one for solar feed, one for solar return) to the return line between filter and salt cell (which is disconnected at the moment). We are now ready to add the solar but, as you can see, it is very tight on space for the normal setup. Is the 3-way valve currently on the line useable where it is currenty installed or do I need put a check valve in somewhere to prevent backflow to the cartridge filter? I don't think it is a proper solar 3-way valve (though I have one). The pump is about 2 feet higher than pool surface and the solar panels are up on a high roof 25' away. I know the goal is for the solar feed line to be able to automatically drain when pump is off and that is done by installing a check valve between filter and the 3-pay solar valve. Not sure how to make that work with current setup. Any guidance on the proper plumbing appreciated!

 

[mas985]

A check valve is normally placed between the solar valve and filter where there is no room for it. Also, they stubbed the pipes upward which is going to make it difficult to plumb and subject to damage when you do add solar.

The check valve could go before the filter but in that location they are prone to collecting debris and not sealing very well.

They are also using 2-way valves that are really poor in quality and don't last very long.

My suggestion is to replumb the entire pad.