New to Solar - plumbing help

[sjagannath]

Hi all,

First off, though I don't post much, there is a wealth of knowledge on these forums that have helped me as a new pool owner, so many thanks for that.

I am interested in purchasing some small solar panels. Looking at the ecosaver space saver 30" x 10' panel for my 21' AGP. My goals are to raise the temp of my pool a few degrees in the summer. The pool has been between 75 and 77 degrees pretty consistently so far this season. I do use a solar cover at night. I'd like to see Temps hover around 80 and for space reasons, I'll eventually be able to fit 4 of the ecosaver panels giving me roughly 50 Sq ft of solar panels.

I currently have a Hayward Matrix 2 speed 1.5 HP pump...do you think it would be sufficient on low speed to pump up 12' to my shed roof, and back 25' to the pool? Worst case, I will have to use the pump on high speed.

Also, could someone point me in the right direction as far as plumbing the panels? I have just the pump, sand filter and one eyeball return currently- a pretty basic setup. I want to make sure I do this correctly.

 

[f3justusc]

You are going to need to consider several things. I have panels very similar to what you are purchasing and I like them and they do heat my pool. But, there are some things that you can do to make your life with solar easier.

1. Without a solar cover, you can expect to lose 5+ degrees each night which means you will have to make that up each day. You should consider investing in a solar cover and then, your heat loss overnight will likely be less than 4 degrees.

2. You are going to need to purchase a three way valve. After the filter, install the valve. This configuration allows you to send water to the solar or to the pool or some combination of both. Without a three way valve, I am not sure how you would manage it. Amazon has them starting at $15. Jandy Never Lube valves are about $45 and people love them. I have had the $15 valve for almost two years and it works just fine.

3. When it is anything other than sunny, solar will cool your pool. This is the Bain of my existence. You need an automatic control valve that, based on a setpoint or two, will open/close the three way valve so that the solar only heats your pool. If you do not have a controller, you cannot win and you will add a new worry too your life that you do not need.. Ask me how I know... Sigh

There are other things that forum members will provide but these are my top 3 things that I think are important.

 

[pooldv]

+1 on getting a solar controller, best thing ever. Deets in my sig and pics in mg build thread.

 

[mas985]

The matrix should work fine for that applications. It has fairly high head. However, if you put in a VRV (vacuum release valve), you will need to prime on high speed before switching to low speed. Some controllers do this while others do not so it isn't a given.

 

[Hayward Pool]

I do not think the Matrix will work with a solar system pumping up 12' on low speed. When you purchase the solar panels make sure to find out the flow rate for all panels bought. This will give you a idea on flow requirements.

 

[mas985]

There are several solar setups on this site where this has been done successfully, including myself.

The pump would not be pumping "up" 12' on low speed because once the panels are primed on high speed, there is no longer any static head. The downward fall of the water cancels the upward rise of water in terms of static head and weight so the pump no longer "sees" the rise as higher pressure. However, it still requires priming on high speed and it also requires the VRV to be low enough so it remains closed with the lower pressure at low speed.

As for the flow rate through the panels, for most setups to maximize efficiency, you need about 0.1 GPM/sqft. However, if energy use is more important than panel efficiency to the pool owner, then you can most certainly operate at lower RPM. The panels just may not produce as much heat.

 

[Hayward Pool]

I agree mass985, but the Matrix is still a low to medium head pump. Not sure what will happen.

 

[mas985]

Max head on the Matrix is over 55' of head so no problem priming panels at 12' high on full speed. The max head of my pump is around 63' of head and it has no problem priming panels at 25' height.