Smart Toilet Cleaning: Clean When the Air Says So, Not When the Clock Does

Most washrooms are cleaned on a fixed timetable, whether they need it or not. An IoT ammonia sensor changes that. It monitors the air in a toilet block and stays quiet while levels are normal, so no labour, water or detergent is wasted on a washroom that is already fresh. When ammonia rises past a set level, it warns the facility team that cleaning is needed. The result is cleaner washrooms, fewer unnecessary rounds and lower costs.

Why It Is Needed

Fixed schedules cause two problems at once:

• Over-cleaning: A washroom used by 5 people gets the same treatment as one used by 500, wasting staff time, water and chemicals.
• Under-cleaning: A rush, leak or blocked drain can make a washroom unpleasant long before the next round, and nobody knows until someone complains.

Ammonia is released as urine breaks down, so a rising level is an early sign that a washroom needs attention.

Where It Is Useful

Offices, malls, schools, hospitals, railway stations, airports, highway rest stops and factories. Any site with many shared washrooms benefits.

Our Solution

We built an ESP32-based air-quality monitor for washrooms:

• Gas sensing: An MQ135/MQ137-class sensor tracks air quality continuously.
• Live data: Readings are sent over Wi-Fi to an MQTT broker, so they can feed dashboards and alerts.
• Works offline: If the Wi-Fi fails, the device uses its BLE for communication, so staff can still view readings from a phone.
• Easy access: Open its application to see live status, Wi-Fi and MQTT state.
• Status LED: Technicians can check device health at a glance.

The system reads normal (no action), rising (warning) or threshold crossed (cleaning alert to the supervisor). Thresholds can be tuned per site.

Benefits

• Fewer unnecessary cleaning rounds and better use of staff
• Less water and detergent wasted when no ammonia is detected
• Faster response before visitors complain
• Consistently fresher washrooms and better user experience
• Usage data to plan shifts and maintenance
• Lower costs and a greener footprint

Beyond Odour: Building a Fully Automated Smart Restroom

While ammonia sensors are critical for detecting foul odors and immediate cleaning needs, a truly automated restroom system relies on a multi-sensor ecosystem to optimize hygiene and custodian schedules. To move from simple odor management to a fully dynamic cleaning model, an IoT-enabled restroom integrates several key sensor technologies:

• VOC (Volatile Organic Compound) Sensors: Monitor total air quality by detecting a wide array of chemical compounds, air pollutants, and organic gases beyond just ammonia.
• Temperature & Relative Humidity Sensors: Track environmental moisture build-up and ventilation efficiency, preventing mold growth, bacterial buildup, and damp surface conditions.
• People Counters & Traffic Sensors (Time-of-Flight / IR): Count foot traffic and stall visits to trigger cleans based on actual user volume rather than arbitrary timer schedules.
• Smart Flush Motion Sensors: Track toilet and urinal flush counts directly to separate full fixture usage from visitors who only enter for sinks or mirrors.
• Consumable Level Sensors (Ultrasonic / Distance): Measure remaining toilet paper, paper towels, and soap levels in real time to prevent outages.
• Leak & Moisture Sensors: Installed along plumbing bases and floor boundaries to immediately alert staff to water overflows, pipe leaks, or slipping hazards.
• Waste Bin Depth Sensors: Monitor trash container fill levels so custodians empty bins only when full, saving time and plastic liners.
• By combining detailed air quality tracking (ammonia, VOCs, temperature, and humidity) with foot traffic, supply levels, and leak detection, you create a predictive maintenance system that keeps restrooms consistently clean while reducing unnecessary cleaning rounds.

Want a Smarter Washroom?

WeMakeIoT builds custom IoT solutions, from sensors and firmware to dashboards and apps. Contact us today for a free consultation and demo of a smart washroom monitoring system, or any similar air-quality or facility solution.