Lowtech Graph lists low-tech options for every need of a home. Here you can compare them, find tutorials to build them, and link them together into a circular system. Why low-tech?
Zeer pot (evaporative pot-in-pot cooler)
Passive
One of 4 ways to meet this need. Cost, carbon, footprint and rankings are relative to other solutions for the same need, not absolute.
What your site needs
Shaded, ventilated siting; a dry-air location improves performance, flagged as reduced effectiveness in humid climates
Two unglazed clay pots, one inside the other, with wet sand between them. As water evaporates from the sand it draws heat out of the inner pot, keeping it about 10 °C cooler than the air. Vegetables keep two to three weeks longer with no electricity, but it only works well in dry air, which Normandy rarely has.
Levels are relative to the other options for this need, not absolute. Fewer dots is lighter.
Zeer pot (evaporative pot-in-pot cooler) (This page) Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Low · Skill to build: Basic · Upkeep: Regular · Change to daily life: Daily · Works without the grid: Yes Choose it if your climate is warm and dry and you want vegetables to keep weeks longer with no power.
Root cellar (passive cool storage) Can I use it? Not in a flat · No rebuilding needed What does it cost me? Upfront cost: Low · Skill to build: Basic · Upkeep: None · Change to daily life: Occasional · Works without the grid: Yes Choose it if you want to keep vegetables and fruit for months with no power.
Electric refrigerator Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Medium · Skill to build: Basic · Upkeep: Light · Change to daily life: None · Works without the grid: No Choose it if you want food kept cold in every season.
Insulated cool box Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Low · Skill to build: Basic · Upkeep: None · Change to daily life: Occasional · Works without the grid: Yes Choose it if you want food kept cold through a power cut, or away from the kitchen, with no power at all.
We don’t list sizing or quantities, as the yield of each technique depends on the quality of its build. The catalogue compares options but doesn’t dimension them. Regulatory notes are indicative, with a French example, and need to be confirmed locally.