Solar pool heater

[bradatkins]

Here's an updated picture describing the flow



Here's the diagram I'm using as a general guide:



The main pipe coming out of the filter is 1". The loops on the roof will be 1/2". The flow is reduced when flowing up to the solar loops, of course, but still acceptable.

As for winter, I plan to leave it in place, and blow out the lines. I will be taking down the solar loops as the pipe is a little more fragile then the main system which is poly pipe.

[bradatkins]

Here's a picture of the first coil. I've only built 2 for this year. Plan to build more next year:

[CarlD]

Big Dave means calories.

A calorie (actually a kilo-calorie) is the heat energy necessary to raise one liter or one kilo of water one degree Celsius. A BTU (British Thermal Unit) is the equivalent: the amount of heat energy necessary to raise one pound of water one degree Fahrenheit.

Thin tubes can conduct more heat energy to the water flowing through them, but put up a high resistance to water pressure. Thicker tubes conduct less energy but have lower resistance. Therefore, several thin tubes parallel to each other can lower resistance AND increase conduction.

The more water you can flow through ANY system, the more heat you will add to your pool. The limiting factors are causing leaks (bad) or, possibly cavitation. Don't be fooled by the false adage that you have to run the water slowly through the panels so it can heat up. It SEEMS to make sense but actually doesn't. Again, the confusion is between heat energy and temperature, and we want our solar panels to move heat, ie, calories/BTUs. A very heavy strong flow that's only 1 degree warmer than your pool will STILL heat it faster than a trickle of hot water.

And, just to add to the confusion, as the water in the pool gets warmer, so will the water it feeds to the solar panel, that then STILL comes back warmer, even if only one degree, and warms the pool more!

I've been running solar for 11 seasons now. I've not built my own panels, but the principles are the same.

[geohec]

Here's a picture of the first coil. I've only built 2 for this year. Plan to build more next year:

If you don't mind me asking, I was curious how much your two coil system cost you?

Also, are you happy with the results this year?

I have a low lying roof next to my AGP and I am considering buying a system or building one. What you've done seems like something I could do. Any info would be helpful. Thanks.

[bradatkins]

It was $26 for the 200ft of tube and about 30$ in connectors. I built it too late in the season to take advantage of them (lack of sun).

I don't expect 2 to make any difference. I'm expecting to have to make a few more

[geohec]

It was $26 for the 200ft of tube and about 30$ in connectors. I built it too late in the season to take advantage of them (lack of sun).

I don't expect 2 to make any difference. I'm expecting to have to make a few more

Thanks for the info. So your ideal system with say 5 or 6 coils would be around $140-$200. I looks a lot more durable then some of the manufactured options out there. I see they sell a lot of repair kits which makes me think that they're fragile.

After I finish my deck, then I'll have to make a decision on which way to go. Thanks for the info.