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?
Insulated cool box
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
A source of ice or frozen packs.
A well-insulated box that keeps already-cold food cold with ice or frozen packs. It makes no cold of its own: it carries it, from a freezer, a winter night or a shop. Its place in a low-tech home is the power cut: a fridge keeps food safe for about four hours without power, and a cool box with enough ice keeps it at 4 °C or below well beyond.
Levels are relative to the other options for this need, not absolute. Fewer dots is lighter.
Insulated cool box (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: 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.
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.
Zeer pot (evaporative pot-in-pot cooler) 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.
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.