HomeDesign rev A (stages 1–6), not built

DampHome

One wall hub by the RO purifier: filters due, water on the floor and the damp wall, in one app

Does the job of PureTrack (RO litres, pump hours and filters due), WaterLeak AI's home sensor (water on the floor under the sink) and MouldGuard (wall surface humidity, dehumidifier or exhaust fan on a plug) from one hub with one brain.

Who buys it: Families in damp monsoon cities in India (Mumbai, Kochi, Kolkata, Chennai) who own an RO purifier; sold and fitted by the RO service dealer as part of the yearly service plan (PureTrack's channel).
Why it pays: One fitted box instead of three: $109 against $277 for our three products bought separately (est.). A leak caught the same evening saves the cabinet base and the floor (est. ₹5,000–25,000 for a cabinet and tiles); the dealer stops calendar visits that come too early (PureTrack estimate about $2,100 a year on 1,500 customers).
Target price: $109 per home, about ₹8,999 (target); no monthly fee for the family; dealer plan as PureTrack
First-minute wow: The dealer fits one white box by the purifier in 20 minutes, and the family's phone shows litres today, filters due, a red 'water under the sink' card and the wall's mould risk.

See the CAD design Concept page

DampHome 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

Three single-job products, three apps → one hub, one brain (ESP32-C6), one 24 V supply from the purifier, one app
RO leaks are the second most common RO service call (RO Care India blog) and soak the cabinet base → the leak foot sits on the cabinet floor under the purifier and sink, cabled to the same hub
Monsoon damp shows first behind and under the sink cabinet → MouldGuard's wall tag sits on that wall and reads the surface humidity, not just the room
A purifier switched off at the wall left PureTrack blind → 2 x AA backup keeps the leak and damp jobs alive
Homes without Wi-Fi → PureTrack's BLE sync on the technician's visit still works for all three jobs
Dropped: DryBase's weighing board, WaterLeak's riser node, valve and LoRa gateway, TankWatch geyser probes (other rooms or buildings)

Use case

RO tank fitting starts to drip during the monsoon

FamilyRO service dealerTechnician

01Trigger: the storage-tank fitting inside the purifier drips onto the cabinet floor at night
02Detection: the leak foot's contacts go wet; the hub chirps within 1 s
03Alert: the family gets a push and SMS; the dealer sees the same card
04Action: the technician visits the next morning with a new fitting; the wall tag shows the cabinet wall dried back below 70% in 2 days

Outcome: Cabinet base and floor saved; one visit instead of a repair and a repaint (est. ₹5,000–25,000)

How it works

Architecture

01
Sense: hall flow sensor and pump current (RO), two-contact leak foot (floor), SHT45 and wall NTC (damp wall)
02
Decide: ESP32-C6 counts filter life, tests wet or dry and works out the wall-surface humidity
03
Send: Wi-Fi MQTT to the app; BLE to the technician's app where there is no Wi-Fi
04
Tell: push and SMS to the family, due list to the dealer, plug on for the dehumidifier or fan

Hardware

Real parts, buyable today

Bill of materials: about $41 per home at qty 100 (est.); optional listed smart plug about $15 extra.

Block	Part	Why this part
Brain + radio	Espressif ESP32-C6-MINI-1-N4	Wi-Fi 6 and BLE 5 in one module, runs all three jobs
RO water	DIGITEN 1/4 in QC hall flow sensor + TI INA226	Litres poured and pump time, as PureTrack
Leak	Two M3 A4 stainless contacts in a printed foot + TLV7011	Wet cabinet floor wakes the brain in 1 s
Damp wall	Sensirion SHT45 + TDK B57861S NTC in MouldGuard's wall tag	Humidity at the wall surface, where mould starts
Power	TPS560430 from the purifier's 24 V + 2 x Energizer L91 backup	No extra adapter; alerts survive the purifier being off

Mechanical

Printable CAD

7 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

Three places, not one: purifier, cabinet floor and wall tag need two 2 m leads; a messy install loses the dealer's 20-minute target
Flow sensor food-contact evidence (IS 9845 / NSF/ANSI 61) still needed from the OEM before any sale
Leak foot only finds water where it stands; a drip behind the cabinet can be missed
A damp reading cannot fix seepage: the app says 'needs a waterproofing check', never 'mould-free'
Purifier makers (Kent, Eureka Forbes, Aquaguard) could add a leak and filter app themselves
Smart plug local APIs differ by brand in India; dehumidifier ownership is low (est.)

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