Thursday, December 10, 2009

Hot Weather Solar Water Experiment

Solar Hot Water Experiment
Have you ever noticed how hot water can get in a garden hose that has been lying in the sun? There have been times when we have almost burned ourselves (or killed innocent plants) from just such a thing. This inspired us to do our hot weather solar water experiment.

Here is the list of our materials:

100’ of 1 ½” black plastic water pipe
4 12’ 2 x 8s painted black
8 90° elbows
2 garden hose adapters
16 pipe clamps
Plumbing strap to hold pipes to 2 x 8s
2 garden hoses
Miscellaneous screws

Our wood shed roof is about 30 feet long, so cutting the 100 feet of plastic into 4 pieces, each 25’ long, worked well for us.

We secured the 2 x 8s to the roof, two of them end to end to give us 24’. We made 2 rows, with about 6” in between the rows.

Next, we cut the pipe into 25’ sections, laid them flat and attached them to the lumber; each board has two rows of pipe. We then attached the elbows and pipe clamps.

The cold water goes into the bottom piece of pipe from a garden hose that is connected to our outside water faucet. The system fills from the bottom up to the top pipe. The other garden hose is connected to the top for the hot water to come out. This hose we have connected to a separate faucet at our kitchen sink.

It takes a little time for the hot water to get to the sink, but has worked out great for doing dishes and cleaning up.

Next summer we will try adding some wooden sides around the pipes to help hold in more heat. We can not enclose the pipes because the pipe will only withstand temperatures of about 160° to 180°

This photo shows where the two garden hoses will be connected.
Solar Hot Water


  1. Wow, amazingly creative. I wonder if there is some way to capture the energy for more uses? Maybe running the pipes under the floor for heating purposes? Wiki has a bit on this application:
    Thanks for sharing!

  2. Very cool... perhaps this type of thing could be connected to rain barrels or other rain capturing -- seems like rain would wash dishes okay? maybe not clean enough. ooooh, what about an outdoor heated shower???

  3. I love this idea. This is going to be one of my late winter/ ealry spring projects.

    How far is the shed from your house?

  4. The shed is attached to the house, right off the kitchen.

    I think rain water would work fine, but there would have to be a way to pump it. We are thinking about putting a storage tank under the house with rain gutters going into it and a seperate pump to use for watering animals. A project for another year! And, yes...the solar water would be great for a solar shower!

    We are also thinking of ways to run solar heated water under the floor of the house to help warm it up a bit. Thanks for the link, Steve

  5. We're planning to fit some solar water heating soon - we have a south-facing roof, and we're hoping it will give us all the hot water we need in the summer. Will be interesting, anyway.

  6. I think you will be surprised how well it will work out for you, and it is always fun to experiment!