Post by: Bogie on July 16, 2007, 09:35:10 AM
Post by: Ron on July 16, 2007, 09:39:17 AM
Can you cover it at night? I bet a lot of the solar heating from the day is lost during cooler evenings.
Post by: charby on July 16, 2007, 09:45:53 AM
I remember reading about wood fired hot tubs.
it looked like this one http://www.stewardwood.org/resources/DIYhottub.htm
Post by: Bogie on July 16, 2007, 09:46:42 AM
I mean, sheesh... Some of the kids will just LOOK at something going wrong. They won't get up and try to stop it. They won't go find an adult to (maybe) fix the problem. They just look, because it's not their problem. ARGH! I mean, you'll walk into the john, and the toilet is stuffed. The plunger is right next to it. Has it been used? Sheesh...
People, raise your kids to be self-sufficient.
Post by: Nick1911 on July 16, 2007, 10:05:12 AM
Post by: charby on July 16, 2007, 10:08:26 AM
Bogie: Problem Solved.
so you make a heater from your skills making a condensor for a whiskey still... and who said rednecks weren't resourceful
Post by: Manedwolf on July 16, 2007, 10:21:42 AM
Post by: Bogie on July 16, 2007, 10:33:49 AM
Post by: K Frame on July 16, 2007, 10:38:08 AM
Post by: HankB on July 16, 2007, 10:52:26 AM
If the kids are as bad as you say, then anything else I suggest (for example, a solar concentrator heating water pumped through tubing) would potentially be worse than the black tarp already mentioned, due to a need for some electrical connections to run a pump, if nothing else.
Post by: Brad Johnson on July 16, 2007, 11:00:46 AM
By the way, copper pipe would be best but, as you are aware, is pretty high dollar these days. You could probably get away with black poly.
Attach the insulated panel and corrugated metal to the plywood (will probably want to use small bolts going all the way through the back of the plywood. Layer it plywood, panel, metal. Paint the face black using high-temp paint. Arrange the pipe across the panel using the corrugations as a guide. Box it with the 1x6s and cover with the plexi (you may need to fashion a few stand-offs or supports for the center). Put the pump on the intake (cool) side of the panel, not the outlet (hot) side. Use the cheapo foam insul-wrap sticks on the outlet side (mostly for your protection). Put the pump on a timer to run during the day.
On a sunny day, don't be surpised if the outlet temp is in excess of 120 deg F. Maybe more.
Brad
Post by: 280plus on July 16, 2007, 11:22:02 AM
BTWan uncovered pool loses heat 3 times faster than a covered one.
Post by: roo_ster on July 16, 2007, 11:36:54 AM
Post by: client32 on July 16, 2007, 11:44:44 AM
When I lived in Florida, a lot of folks used commercially installed solar pool heaters consisting of black tubing on their roofs.
Is it just looped several times in a big circel around an entire side of the house?
There is a house that I drive by occasionally that has something like that. I always thought it was for heating water, but never for sure.
Post by: 280plus on July 16, 2007, 11:45:40 AM
Post by: armchair warrior on July 16, 2007, 01:42:11 PM
My dad got a cover that was like heavy duty bubble wrap.
He kept that on the pool most of time.
Pool was about 4' deep.The top 1-1.5' would get 80-85*.
After swimmin' around the pool was 75-78.
Post by: 280plus on July 17, 2007, 04:57:25 AM
Post by: jeepmor on July 25, 2007, 02:36:24 AM
The ABS plastic angle works well also. They should be plumbed in series for best effect, this way they get heat input the whole path. Parallel piping gets you about 1/2 the heat that a series system would simply employing only two units. Black plastic or coating on the bottom of the tank will help a lot. Black is the color that absorbs radiation best, but this should be obvious.
Beyond that, it's gonna be some math. Simply put q = m cp (Tout-Tin)
q - energy flux
m - mass flow rate (remember mass, not volumetric flow)
Tout - Temp out (heater outlet temp)
Tin - Temp in (pickup temp)
cp - water specific heat thermal coefficient. Use avg between Tout and Tin.
Based upon this, you then need to know how much heat energy you are putting into the system. Barring the BBQ example (genius, but hokey as hell) you'll need to know what the solar flux for your area and time of year when you prefer to use it. You then need to consider your design parameters. How much room to you have for said system, do you have the ability to face it south, etc. Then you need an adequate pump to make it all work. My suggestion would be to oversize your capacity by a factor of 2x or more and then employ a variable speed pump or some other mechanism so you can throttle the output to acheive the temperature output you want.
Post by: K Frame on July 25, 2007, 04:54:21 AM
Post by: 280plus on July 25, 2007, 07:13:41 AM
Post by: 280plus on July 25, 2007, 07:18:04 AM