DIY Thermosyphon
A thermosyphon is a very energy efficient way to supplement the hot water needs of an off-grid home or out building. A large system can even be employed to serve the needs of a household. The entire system works on the principle of rising heat. Depending on the placement of the water storage tank, a small solar-powered pump may be needed to pump the water to lower levels of the building. If the storage tank is below the main water usage areas the entire system can be built quite economically. Does this Spark an idea?
Things You'll Need
- 3 8-foot 2-by-4s
- Framing nails
- Circular saw
- Hammer
- 8 foot-by-4 foot plywood board
- 7 foot-by-14 inch aluminum flashing roll
- Tin snips
- Framing tacks
- 8 8-foot pieces of 1 inch diameter PVC piping
- 18 90 degree 1 inch PVC fittings
- 9 PVC fitting couplers, 1 inch
- 1 PVC T fitting, 1 inch
- 1 inch to 3/4 inch PVC screw fitting
- PVC sealant glue
- Epoxy glue
- Flat black spray paint
Instructions
-
-
1
Cut one 2-by-4 in half with the circular saw so there are two 4-foot long pieces. Create a rectangle with the whole 2-by-4s and the two halves you just created. Secure the rectangle together with framing nails.
-
2
Attach the plywood backing to the rectangular frame with framing nails.
-
-
3
Unroll the aluminum flashing and cut it with tin snips to fit the interior of the rectangular box. Tack it down with framing tacks.
-
4
Cut the PVC piping into 4-foot sections.
-
5
Lay out the sections parallel to the four foot sections of the frame. Dry fit these connections in an S pattern with two 90-degree fittings held together with a coupler.
-
6
Attach the 1 inch to 3/4 inch PVC screw fitting to the top end of the S piping. At the other end attach the a 90-degree fitting to the T fitting and create a loop. This creates a closed system with a screw fitting at the top end.
-
7
Glue all of the fittings in place with PVC sealant. Mix the epoxy and use it to glue the PVC down to the aluminum flashing.
-
8
Paint the entire unit flat black. This coloring will help the thermosyphon collect heat and warm up the water on the inside of the system.
-
9
Lean the unit up against the exterior wall of the building near the access to the water piping. Connect the screw fitting to a pipe leading to the water tank.
-
1
Tips & Warnings
If the thermosyphon is at a higher elevation than the water tank a pump will need to be attached at the top of the piping between the screw end and the existing piping to push the heated water down into the tank. This pump can be run by a small solar panel or hooked up to a regular AC outlet.
Always wear heavy work gloves when working with tin snips. The snips are sharp as are the edges of the metal they cut.
