The ladder
The rung ladder
Four rungs, defined by what a room reads like rather than by how many drops went in. Pick the rung first, then the carrier, then the position.
| Rung | What it claims | Covers | Readable at | Typical rooms | The ladder |
|---|---|---|---|---|---|
| L1 Barely there |
Readable only within arm's reach, and only when the room is already quiet. | 1–5 m2 | 0.3–0.8 m | Wardrobe, car cabin, bedside, a single drawer bank, the towel zone of a small bathroom. | Card published |
| L2 Close range |
Clearly present at seating distance, faint at the door. | 3–12 m2 | 0.8–2 m | Bedroom, study, bathroom, small kitchen, car. | Card published |
| L3 Half the room |
A defined zone of scent covering roughly half an open room, with an unscented far end. | 10–26 m2 | 2–4.5 m | Living room, open kitchen, a studio flat's main volume. | Card published |
| L4 Whole room |
Readable corner to corner the moment you walk in, with no unscented end. | 18–30 m2 | 4–8 m | Large living rooms, open-plan kitchen-diners, entrance halls above 8 m2. | Card dated 2026-11-04 |
How a rung is decided
A rung is set by three measurements taken from the doorway: how far from the carrier the scent is still readable, what fraction of the floor area it covers, and whether the far end stays genuinely unscented. The three have to agree. A carrier that reads strongly at two metres but fills the whole room evenly is an L4 with a weak corner, not an L3.
Air exchange
Designed for closed volumes. In a draughty room L1 disappears entirely within twenty minutes, so treat airflow as a hard ceiling rather than a modifier.
What you should notice
- L1 — You cannot smell it standing in the doorway — correct for L1, not a fault.
- L2 — You notice it when you sit down and stop noticing within ten minutes — habituation, not failure.
- L3 — One corner reads scented and the other does not — that is the intended shape of L3, not an imbalance to correct.
- L4 — You smell it before you see the carrier — correct for L4.
How to adjust it
Step up by adding reeds one at a time, not by switching direction. Each additional reed on a 4-reed diffuser adds roughly 15% output.