Makeshift solar heater

[jeffchap]

This was the first year that I left my AGP filled over the winter. We've had some warm weather recently, and the water started getting green, so I was forced to open it up much sooner than I would normally.

Consequently, everyone is anxious to get in but the water is still freezing cold. So I patched together a little makeshift solar heater that I hope will help speed things along.

All I did was tap into the 1.5" return hose between my pump and the pool with a 2" PVC tee with a 5/8" connection for a garden hose. The 2" threaded connectors on either end mate right up with the Intex hoses with the addition of an extra rubber washer.

For now I'm just running 100' of black garden hose along the ground, but my plan is to build a shallow box to hold it all coiled up in, with a Plexiglas cover to hold in more heat.

The flow seems adequate. It's only about 60 deg right now, so the water isn't real hot, but it's definitely warmer than what's in the pool, so it can't hurt, right? I'm anxious to see what it does once the temps get back up near 90 and I have it all enclosed.

All told, I have maybe $25 in this project so far, not counting the hose. The box will undoubtedly be the most expensive part.

 

[pooldv]

Sweet, that definitely won't make it worse! Warmer is always better.

 

[Kiss4aFrog]

You need to slap a thermometer on there to see what kind of rise you're getting.

Do you cover it at night ??

 

[mas985]

Have you done the math on that?

100' of 5/8" garden hose is 5.2 sq-ft of surface area. Horizontal insolence at your latitude is at most around 2600 BTU/sq-ft/day during June/July, so the most you could possibly add in heat is 13520 BTU but that does not account for heat loss which should be pretty high for that setup. So the best outcome would be about 0.27 degrees per day but I think you would be lucky to get half that amount of rise.

 

[jeffchap]

No, I haven't. But thanks, now I don't need to. I don't know how effective it's going to be, but the water coming out of the hose is noticeably warmer than the water going in. So for what I've got invested in it, it can't hurt. I'm going to go get a pool thermometer today to see what the difference is.

Frog, no I didn't cover it overnight last year. I installed a Hayward through the wall skimmer last year, and it did such a better job that I just skipped the hassle of covering it at night. But yes, the tradeoff was that it never got as warm as in years past, due to the evaporative cooling overnight. So if this rig makes any difference at all, I'll probably leave it hooked up all summer.

 

[mas985]

Don't forget that the pool itself captures heat. Assume 60% capture, the BTU rise for the pool is 312000 BTU or 6.23 degree rise (again in June and July). So it may be difficult to even see the contribution of the host unless you have two pools side by side to compare.

 

[JasonLion]

To expand a little on what mas985 is saying: the amount of heat you can get out of a solar heater is a function of surface area exposed to sunlight (at best). A typical solar setup will have several 40 sqft panels, to get the largest practical area.

It would cost a bit more than your current setup, but even one panel would give you a noticeable temperature boost and not cost all that much. A solar cover would also make a noticeable difference.

 

[jeffchap]

Well, if nothing else, I'll hang the hose on the ladder and the kids can use it to wash the grass off their feet before they get in.

 

[jeffchap]

Just a quick follow up...



Finally got a sunny day yesterday. Air temp was around 80 deg. My pool was between 76 and 77 deg, and the water coming out of the hose was 82.



Of course, as others pointed out above, there's probably not enough volume being moved thru this to make any noticeable difference, but I'm going to leave it hooked up as a foot wash and a spray fountain.

 

[DarrelB]

Sounds good to me! Always nice to have something to wash the feet off with for sure.