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?
DIY activated-charcoal air filter
Passive
One of 2 ways to meet this need. Cost, carbon, footprint and rankings are relative to other solutions for the same need, not absolute.
A bottle or box filled with activated charcoal, left in a room without a fan. Charcoal traps some fine dust and chemical vapours from the air passing it. It is a cheap extra for cleaner air, not a replacement for ventilation, and its effect has not been measured.
Activated charcoal media: 3-6 months before adsorption capacity saturates and needs replacing (same order as the source's own lack of performance data, flagged Tier D already)
Levels are relative to the other options for this need, not absolute. Fewer dots is lighter.
DIY activated-charcoal air filter (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: Light · Change to daily life: None · Works without the grid: Yes Choose it if you want a cheap, homemade extra for one room’s air.
Low-VOC / natural material selection Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Medium · Skill to build: None · Upkeep: None · Change to daily life: None · Works without the grid: Yes Choose it if you want clean indoor air from the start, through what you build and decorate with.
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.