Open Source Solar Water Heater

Basics

• A Device that uses Solar Thermal to heat water
• Can be used from cold to near boiling (see Open Source Solar Steam Generator ) for water to Wet Steam, and Open Source Steam Superheater for Wet Steam to Dry Steam
• There are many ways of doing this but this page will focus on pancake coil type designs, see Open Source Thermosyphon for thermosyphon designs
• This page may use tube/trough designs, but pancake seems like the main one as of now
• Need to look into if these can be grouped for boiling temperatures (this may lead to Steam Hammer and/or overpressure explosions, but perhaps with the right precautions (Steam traps, overpressure valves. etc)

Existing Open Source Designs

• This Design by the Youtube Channel "Dessertsun02" Uses a copper coil with a metal reflector behind it, and a wood frame

Minimum Viable Product

• Should be able to reach near boiling (~80C is what most existing designs could reach in one stage)
• Should be a small flat square (less than 1m^2 wide, and less than 5 cm deep?)
• Should use standard hose fittings for both the "in" and the "out"
• Optional temperature probes
• perhaps have a thicker and slightly wider model with insulation

Basic Design

Box

• A wood or metal box
• Optional insulation

Backplate

• Sheet metal
• make reflective or dark as well?

Coil

• Standard OTS refrigeration coil, or custom bent tubing
• Has the standard fittings at each end

Insulation

• Foam and/or fiber for the main areas
• Glass and air/vacuum gap above coil, or would the walls and cost make it not worth it?

Temperature Probes

• Attach right above the hose adapters
• Wires go where?

Paint

• Most likely standard black paint, but the darker, the better
• Not 100% needed, but is a cheap way to increase absorbtion

Heat Exchanger?

• Open Source Liquid-Liquid Heat Exchanger

BOM

• ~1m Sheet Metal (what metal?)
• Fiberglass insulation
• Foam Insulation
• Either copper piping, or an OTS refrigeration coil
• Fittings
• Optional temperature sensors
• Perhaps Wood or Plastic Exterior

External Links

• The Wikipedia Page on Solar Water Heaters