SunHeater solar which is in and out?

[Ellie]

I cannot for the life of me figure this out. I had my 2 solar panels on the ground and now put them on a fence. They are now end to end; not side by side like in all the illustrations.

So, the label ends are facing each other. I will put the "in to solar in the bottom right one, .... so now the top right is the "out to the next panel" one. Which do I connect it to on the left one? can it go in the left top which would be easier to plumb, or does it always have to go in the bottom...

I do hope someone can understand what I am doing...(obviously I don't)

Thanks,
Ellie

[Poconos]

Ellie,
You would always want the flow to go from bottom left to top right. Then series the panels. Personally, I would do it different. I would maximize flow and reduce temperature difference between solar panel input and output. Explanation.....maximum heat transfer occurs at maximum temperature differential. In simple terms, the hotter the panel the less heat it absorbs to transfer to the water flowing through it. The more flow you get through the panel the lower the temperature differential between the panel surface and the water, thus maximum heat transfer. CarlD has said it many times that the surface of the solar panel should be cool to get maximum heat transfer. This is accomplished by plumbing the panels in parallel. By doing this it reduces the flow restrictions and maximizes the heat transfer to water. In my system I divert the pump output 3 ways. Field solar heater, mat solar heater, then straight to the returns. I maintain at least 15 GPM through each of the three paths...roughly. Depends on how I throttle the individual valves.
Al

[CarlD]

Yup!

If resistance is an issue, parallel is better. If it's not an issue, series can be fine.

If it's a sunny day, and everything dark is hot to the touch, but your panels are cool, then they are doin' their job!

Al understands the physics and thermodynamics better than me--I just use common sense but it gets us to EXACTLY the same place--everytime.

[Watermom]

Our Al?????? Nah, can't be. He just THINKS he knows more than us, Carl. But, we happen to know better, don't we buddy?

[Ellie]

So then, I can pipe in wherever I want and pipe out wherever I want? Sounds too simple.

Ok, in right bottom. from pool ...out right top .... in left top and out left bottom...to pool.

Yes?

Thanks,
Ellie

[Ellie]

Poconos,
I think I got it wrong again. I am stuck with the configuration of these two panels end to end on the fence. The labels are toward one another in the middle. One label is facing up and the other down given how you have to "hang" them.

So you think that I should go from the pool to the solar on the bottom left hole ... out the top left... then into the top right or bottom right?

I am not understanding if it matters which in and out occur on the label sides.

Man, I am lame at trying to figure this out. My brain tells me that it does not matter as long as it goes in and out one on the label sides. Capping the non label sides, of course.

Ellie

[Poconos]

I think your heaters are in a loopback mode. My definition. Input and output on the same end. If you are going to series them then feed one at the bottom, out at the top then to the other heater at the bottom and the final output at the top of the 2nd one. Personally, I would parallel them. Split the feed to both bottoms and combine the two tops. Better flow and better heat transfer efficiency. In parallel you wouldn't be feeding water that's already warmed to the 2nd panel.
Al

[kaybinster]

Unless there is something very odd to these panels there should be two connections to each one and it really should not matter which is used for inlet and which for outlet -- it is a very simple heat exchanger. You have two of these, so you have a choice of using them in series or in parallel. If you use it in series (cold water in to unit one and hot water coming out goes to input of second unit) you will get the hottest possible water coming out but lower flow due to pressure drop. It is also possible that the heat of the outlet may exceed the temperature limits of the plastic -- you need to check that. If you run them in parallel you will get maximum flow, and get the most heat out of the system; althought the outlet temperature will not be as high as had you run them in series.

[Ellie]

I am finally getting it. I think the parallel is better. I can also then use one or two if I put a valve in.

Now, if I split the line coming in to go to both bottom "in" lines in the solar panel.. you said to combine the top. Where then would they come out and back to the pool? Now, am I going to the ends where I had them capped off?

Plan to get this done tuesday. Thanks for any help.

Ellie

[Poconos]

Ellie,
Just to be sure it is clear, you don't want the 'hottest' water. You would get that with low flow and series panels. You want MAX HEAT transfer which would be at max flow which implies parallel hookup. Temperature is different than heat. If this concept still isn't clear, we can explain it further with some analogies but it will take some words.
Al