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jimpeterson · Oct 10, 2008, 04:06 PM

Hi, Guys... Last year, I installed a solar hot water system on top of my house, basically consisting of 220 meters of curled-up 3/4" black hose. I was able to get 125 degree water on a sunny day.
One problem I have is with low water pressure. So this year, instead of trying to push water through the 3/4" hose, I am looking into using a series of large diameter plastic pipe, maybe 4" diameter, mounted on a slight incline.
Have any of you guys done anything like this?
The roof is 20' off the ground.
All I'm doing, is filling a Jacuzzi tub.
Thanks,
Jim Peterson
Gardnerville Nevada/Bacubirito Mexico

ballengerb1 · Oct 10, 2008, 04:19 PM

Are you using city water pressure to drive your solar heater or is there a booster pump? I had a commercially made mat system that also had problems, it was do to the extra lift and the length of the systems tubing. I added a booster pump and all was fine. I was heating an above ground pool.

jimpeterson · Oct 10, 2008, 04:48 PM

I'm using city pressure, which is bad at it's best time. I had an RV 12 volt pump down there, but didn't get a chance to hook it up.
I was a fireman in the Airforce about 100 years ago, and at that time knew a little about hydraulics, but have forgotten everything, like amount of pressure to push water through a pipe, etc.

speedball1 · Oct 11, 2008, 07:05 AM

I was a fireman in the Airforce about 100 years ago, and at that time knew a little about hydraulics, but have forgotten everything, like amount of pressure to push water through a pipe, etc.

For every foot of head add .434 PSI. 20 foot to get to your roof would take a little over 8 1/2 poinds of pressure just to get it up there. A booster pump is needed here. Good luck, Tom

Milo Dolezal · Oct 11, 2008, 08:26 PM

I think 4" plastic pipe will not heat up fast, will be too heavy, and black plastic pipe on the roof will probably deteriorate very fast...

We did several similar projects like yours. I would suggest to use 60' of 1" soft copper (continuous pipe ) spray painted black. Connect in-line pump that will suck water out your jacuzzi and push it through the coil back (... coming back by gravity ). You can put the coil on the roof the way you buy it: coiled. No need to cut anything. Just attach it to the roof and connect the ends. Copper absorbs heat easily and will last lot longer.

speedball1 · Oct 12, 2008, 04:58 AM

I'm with Milo on the 4" pipe however I disagree about using copper tubing. In my area copper's like gold so the cost of installation alone would scare hell outta me. When we pipe for solar heat on a pool or house we use 1" or 1 1/4" ABS flexible tubing, (see image). A lot less expensive and easier to run then copper. Good luck, Tom