BTU Output of Swimming Pool Solar Panels

Who wants to put their thinking cap on? I just measured the flow rate and temp change of my pool's solar panels. Temp change is 7 degrees at a flow rate of 2 gallons in 10 seconds. What's the BTU output per hour?

And the quantity of water in which experienced this temperature change?

I would figure it out in joules and do the simple conversion from there.

7 degree change in 10 seconds?

Clearly not providing enough information....this don't sound right...unless your pool a 4 oz

Everything is there lol. 2 gallons of water increased 7 degrees in 10 seconds.

42k btus/hr.

http://www.homepower.com/articles/solar-water-hea ... y/page/0/1

Seems like pissing into the wind LOL

http://www.amazon.com/SOLAR-RING-HEATER-COVER-HEA ... B002WKJ6MO

21,000 BTU ^^^

I myself never heated a pool .... swimming generates its own body heat

Rob got it right!

lsayre wrote:Rob got it right!

Wow. 42,000 BTU per hour of free heat!? Now that is pretty significant! Awesome.

I have the same ladder.

So my 24 ft round pool has about 17000 gallons for roughly 141000 pounds of water. At 42000 BTU it should take about 3.3 hours to help lift the pool 1 degree. During a productive sunny day worth 10 hours I should get a 3 degree lift by the solar panels.

Interestingly enough, with efficiency factored in, that would be equal to about 40 pounds of coal. (If I did that all right.)

Neato.

coaledsweat wrote:I have the same ladder.

Cool I like it. The steps are easy to remove and reinstall.

Lightning wrote:So my 24 ft round pool has about 17000 gallons for roughly 141000 pounds of water. At 42000 BTU it should take about 3.3 hours to help lift the pool 1 degree. During a productive sunny day worth 10 hours I should get a 3 degree lift by the solar panels.

Interestingly enough, with efficiency factored in, that would be equal to about 40 pounds of coal. (If I did that all right.)

Neato.

Don't just dump the coal into the pool .. that did not work. Maybe it must be lit before?

I wonder how much BTU is put into the system from swimming around in it?

davidmcbeth3 wrote:Don't just dump the coal into the pool .. that did not work. Maybe it must be lit before?

Right

davidmcbeth3 wrote:I wonder how much BTU is put into the system from swimming around in it?

The impression that I get is that the water will absorb your skin's heat until its about the same temp as the water. So I wouldn't think body heat would have much influence. Maybe in a bathtub, but not so much in a pool.

I was doing a little more investigation about solar energy. I always get curious about it during the summer. I would love to mount up something to pre heat my DHW like I did with the coal furnace. Anyways, from what I've read, every square foot of direct sunshine has roughly 100 watts of energy or about 283.6 BTU per square foot at the Earth's surface. This is after it's been filtered by our atmosphere where some bounces back into space.

My 42000 BTU measurement earlier came from 160 square feet of solar collector and works out to be 262.5 BTUs per square foot at that heat output. It's under the 283.6 BTU sq/ft/hr, and it should be. Seems like it shouldn't be that efficient. That's like 92.5%. I wonder if my measurement was skewed somehow. I will do more measurements thru the summer and see what I get. I'll get a reading on a larger quantity of water over a longer time period. 2 gallons in 10 seconds is pretty tight lol. Off 1 second would skew results by 10% at that rate.

Thanks for everyone's interest.

Wouldnt it do just as much good to cover the pool tightly with clear plastic? It would be similar to a greenhouse affect.

Of course that would be cheaper and simpler so we cant do that, LOL

Just a thought

warminmn wrote:Wouldnt it do just as much good to cover the pool tightly with clear plastic? It would be similar to a greenhouse affect.

Of course that would be cheaper and simpler so we cant do that, LOL

Just a thought

I always have the pool covered with a "solar blanket" while the pool isn't being used. It's make up consists of two layers of plastic with thousands of air bubbles sealed between. Kinda like bubble wrap. The blanket serves 3 purposes. It absorbs solar energy and transfers it to the water (kinda in the same way you described). It also insulates the surface thru night time. Most importantly it eliminates evaporation which also has a cooling effect.

My efforts do pay off overall. I've had that sucker up to 94 degrees. True story!!