Zeer Pot Evaporative Cooler
Two terracotta pots and wet sand cool produce by evaporation — Zach runs one on his own deck, and confirms it's a mild-cooling novelty in WV's humidity, not real refrigeration.
This works by evaporative cooling: water evaporating out through the unglazed outer pot pulls heat with it, cooling the inner chamber. That mechanism depends entirely on dry air pulling moisture out of the sand — which is exactly why it performs very differently in a dry climate than in WV's humidity.
Materials
- Small unglazed terracotta pot
- Larger unglazed terracotta pot
- Sand
- Water
- Damp cloth cover
The Process
- Place the small pot inside the large pot.
- Fill the gap between them with 1.5–2 inches of sand.
- Saturate the sand thoroughly with water — this is the core mechanism, and it must be kept wet daily to keep working, not just filled once.
- Place produce in the inner pot.
- Cover with a damp cloth.
- Set the whole thing in shade with airflow.
Real-World Performance
Can lower interior temperature 18–27°F in a dry, arid climate. Zach's own deck-run unit in West Virginia confirms the honest version of that claim: expect a mild-cooling novelty effect here, not refrigeration-level performance — WV's humidity works directly against the evaporation this device depends on.