HomeDesign rev A, 28 Oct 2026: smart extractor fan that makes the bathroom's calls itself (7 calls, 5 alone, 2 assist), call light and tone, ATECC608 and tamper switch inside; 15 sensor views checked in the CAD; not built

DampOne

IEMI's one product for the bathroom, laundry and damp: the extractor fan in your ceiling, made smart, so it runs on the cold wall's damp risk and makes the room's water calls itself, in one home app

The 100 mm extractor fan that already sits in the bathroom ceiling, at the same cut-out, duct and grille size, reads the coldest wall and the window with one heat camera, the floor, bath and washer with another, the room's humidity, who is in the room with a radar and running water with a mic; it runs its own fan on the wall's condensation risk, calls water on the floor, a tap left running, a bath about to overflow and the washer's end, shows each call on its grille with a light and a tone, and keeps a signed damp record.

Who buys it: Families in damp homes (UK first), and landlords and housing providers who must investigate damp and mould; later, bathroom fitters and fan makers.
Why it pays: $349 + $2/month instead of about $443 for a smart 100 mm fan (about $150) plus MouldGuard ($69), a WaterLeak home unit ($199) and a CycleTap puck ($25) bought separately, with a wall sensor, a relay box, a leak puck and a cycle puck around the room.
Target price: $349 per smart extractor fan + $2/month family alerts and the damp record (target)
First-minute wow: After a winter shower the fan keeps running on its own until the cold top corner of the outside wall is dry again, 52 minutes, not the 15 a timer gives. Next morning the washer hose weeps while everyone is out; the grille turns blue with a tone and the phone says "Water spreading at the washer, 30 x 40 cm".

See the CAD design Concept page

DampOne concept: the idea and where each part goes — The concept. The CAD design is below, under Printable CAD.

What the research found

And how this design answers it

Rev A (28 Oct 2026): the bathroom flagship is the extractor fan itself. Everything sits in the sealed rim of its 200 x 200 x 30 grille around the air path: XIAO ESP32-S3 brain, two MLX90640 heat cameras (outside wall and floor), SHT45 humidity, LD2410C radar, MAX9814 mic, call light and tone, ATECC608 and tamper switch; the 5 V supply sits in the housing above the ceiling
Makes the bathroom's calls itself: fan boost and run-on from the coldest wall's dew point, condensation and mould-risk hours, water on the floor, a tap left running or a bath about to overflow, the washer done or leaking; no-movement and window-open notes assist; unsure means unsure
Folds MouldGuard: the wall sensor, fan relay module and floor leak pad are gone; the fan measures the cold wall itself
Gaps listed: water shut-off (a certified valve), leaks behind walls and in the airing cupboard (WaterLeak stays listed), shared laundry rooms (CycleTap stays listed), purifier filters (PureTrack stays listed), other rooms

Use case

A damp family bathroom in winter

FamilyTenantLandlord or damp surveyor

01Trigger: two hot showers on a cold morning, then a washer cycle with nobody home
02Detect: the wall heat camera and the SHT45 see the top corner below the dew point; the floor camera and mic see water spread at the washer
03Act: the fan runs on until the corner dries; blue light and tone, then a family alert for the water
04Log: signed damp hours and water calls in the app, shared with the landlord if the tenant chooses

Outcome: The cold corner dries after every shower, a leak is found in minutes, and a damp complaint comes with a signed record instead of an argument

How it works

Architecture

01
Sense: two heat cameras, humidity, radar and mic in the grille rim
02
Decide: the XIAO ESP32-S3 compares the coldest wall pixel with the dew point, and runs the water, bath and washer models; unsure below the line
03
Show: fan speed, call light and tone on the grille
04
Tell: signed calls over Wi-Fi to the family app and a shareable damp record

Hardware

Real parts, buyable today

Bill of materials: about $250 per fan at qty 1 including the fan body (est.).

Block	Part	Why this part
Brain	Seeed XIAO ESP32-S3	One brain with Wi-Fi in the grille
Heat cameras	2 x Adafruit 4469 MLX90640 110 degree	The cold wall and window, and the whole floor, from the ceiling
Air	Adafruit 5665 SHT45	Room humidity and temperature for the dew point
Presence	HLK-LD2410C radar	Someone in the room, even still in the bath
Sound	Adafruit 1713 MAX9814 mic	Running water, drips and the washer
Calls	2 x Adafruit NeoPixel Stick 8 + Adafruit 160 piezo	The call on the grille itself
Security and power	Adafruit 4314 ATECC608 + Omron D2F-01 + Mean Well IRM-10-5	Signed calls, tamper log, 5 V from above the ceiling

Mechanical

Printable CAD

2 parts, generated from code and checked as closed solids. Pick a part to inspect it, or download the STL files to print.

Loading the CAD…

Real CAD · drag to rotate · scroll to zoomReal CAD · swipe sideways

Open risks we are working on

Steam on the wall and window right after a shower changes their emissivity; the damp model must learn to wait or fall back to humidity
Water on a tiled floor shows as a cool patch only while it evaporates; small puddles under 20 cm may be missed (bathroom tests D-T1)
A wet bath mat or footprints look like a spill; the classifier is unproven
The heat cameras are the costliest parts; bare MLX90640 sensors cut the volume cost
Not a flood detector, a medical alarm or a shut-off: it monitors and alerts
Fan makers already sell humidistat and app fans; our edge is the cold-wall control, the water calls and the signed damp record

Design stage only: nothing on this page is for sale. Specifications and prices are targets.