Thaka.AiReviewed 16 October 2026 · schematic not to scale
Build a simple solar heat collector from common craft materials. This is a heat experiment, not electricity generation or validated food preparation.
- 1Solar input / heat source
- 2Collector / absorber
- 3Temperature control and protection
- 4Measured useful heat
Site and operating requirements
- Measure heat demand and site exposure. Separate an educational solar-heating experiment from a pressurised domestic hot-water installation.
- Check materials, temperature limits, stability and burn protection before introducing heat.
Tools and measuring equipment
- Thermometer with suitable range, timer, ruler, stable supports and heat-resistant handling tools.
Output and operating conditions
Electrical output: 0 W. Example 0.3 × 0.3 m aperture at 800 W/m² intercepts 72 W of sunlight before thermal/optical losses. Useful heat must be measured.
Published DOE box-cooker lesson. The source does not specify a universal box dimension or wattage; measure your box and follow its paper template.Parts, quantities and dimensions
| Part | Quantity | Specification / dimensions |
|---|---|---|
| Cardboard box with hinged lid | 1 | Clean pizza box; measure length, width and depth. Use the source’s paper template. |
| Foil, dark paper and clear film | 1 set | Foil sized to the flap, dark paper sized to the base; two clear-film sheets about 25 mm larger than the opening. |
| Tape, support stick and thermometer | 1 set | Ruler or stick to prop the flap; source specifies newspaper insulation about 25–38 mm thick. Use a suitable thermometer. |
Preparation and component checks
- Record box and window size and use the source’s foil, dark absorber, transparent cover and insulation. Tape sharp foil edges and stabilize the reflector before sun exposure.
- Measure an unheated baseline, then compare the same thermometer position and solar exposure at fixed intervals. This educational box is not a validated food-cooking appliance.
Procedure
- 1
An adult traces the paper template and cuts three sides to form a hinged lid flap.
- 2
Line the inside of the flap with foil, place dark paper on the base and seal the opening with clear film.
- 3
Support the flap to reflect sunlight into the box; place outdoors on a stable, nonflammable surface.
- 4
Compare temperature with an unmodified box, log time and temperature, and stop if materials soften or scorch.
Safety and inspection
Adult cutting supervision; no lenses or concentrated beams. Avoid burns and eye glare. Do not use this experiment to cook meat or establish food safety.
Verify the result
Temperature is not power. Measure heat gain with a known test mass and temperature rise if doing calorimetry; account for heat losses.
Measurement log
- Ambient and internal temperature, elapsed time, sunlight/clouds, reflector angle, opening dimensions and any cover leaks.
Maintenance and repeat checks
- Cool before handling or storage; inspect cover, foil edges and reflector support. Replace damaged materials; do not leave cardboard near flame or hot elements.
Troubleshooting
- No output, abnormal heat, noise, vibration or leaks
- Stop and isolate first. Check the documented input, load compatibility, alignment and connections; keep guards fitted and refer specialist systems to their installer.