A subtly obvious e-paper room air monitor
In the cold season we tend to keep the windows closed. The air gets "stale": humidity often rises above 60 %, which can harm our wellbeing and promote mould. At the same time the CO₂ level in the air increases, which impacts our ability to concentrate. So I built a room air monitor that stays unobtrusive as long as everything is in the green zone, but becomes deliberately noticeable once thresholds are exceeded. For my personal love of statistics I also visualise the measurements in a clear dashboard.
A subtly obvious e-paper room air monitor launched on November 18, 2025 with 65 votes, #423 of 9,795 launches that month and more than 95% of that year's launches.
In plain words
A subtly obvious e-paper room air monitor displays indoor air quality by tracking humidity and CO₂ levels. The device remains discrete when conditions are healthy but becomes noticeable when humidity exceeds 60% or CO₂ rises too high, signaling when ventilation is needed. It includes a dashboard for viewing detailed measurement history and statistics. The monitor addresses wellbeing concerns during cold seasons when windows stay closed, helping prevent mold growth and maintain concentration levels.
written from the facts on this page · September 2026
From the sources
This page has moved to /en/blog/epaper-room-air-monitor-part-1/.
Does a similar job
all alternatives →- ALAir Lab – A portable and open air quality measuring device2025 · networkedartifacts.com · ▲497
Hi HN! I’ve been working on an air quality measuring device called Air Lab for the past three years. It measures CO2, temperature, relative humidity, air pollutants (VOC, NOx), and atmospheric pressure. You can log and analyze the data directly on the device — no smartphone or laptop needed. To better show what the device can do and how it feels like, I spent the past week developing a web-based simulator using Emscripten. It runs the stock firmware with most features available except for networking. Check it out and let me know what you think! The firmware will be open-source and available…
I wanted to measure CO2 in my office, so I build a C++ WebServer/App2019 · github.com · ▲146A simple webserver / CO2 Monitor. Contribute to Maddimax/MadCO2 development by creating an account on GitHub.
E-Paper 7-color display showing the current weather2024 · github.com · ▲229A hobby project of mine that was surprisingly easy to put together! I love waking up and seeing the freshly generated image.
theO: Smart Indoor Environment Sensor2018 · indiegogo.com · ▲80Get intelligent insights into your air quality
Live Air Quality Monitor2025 · github.com · ▲19A comprehensive indoor air quality monitoring system built with ESP32-C3 Super Mini and multiple environmental sensors. This project helps you monitor CO2, temperature, humidity, volatile organic compounds (VOCs), nitrogen oxides (NOx), and particulate matter (PM1.0, PM2.5, PM10) to maintain healthy air quality in your home or office.
Low cost CO₂ monitoring (your office) with Prometheus and Go2018 · github.com · ▲127CO₂ & Temperature monitor. Contribute to larsp/co2monitor development by creating an account on GitHub.
More work this month
the category →
Endless lofi beats composed live in your browser, over pixel-art nights in Paris, Tokyo, New York, Hong Kong, Sydney, San Francisco and more. Free, no sign-up.
Work · 26d ago · loficities.com
Smooth Recorder▲257Mac screen recordings that look edited when you hit stop
Work · 20d ago · smoothrecorder.com
Work · 14d ago · readrare.com
Source: Show HN post ↗
Launched alongside, November 2025
the whole month →
Guideflow▲1,338Create interactive product demos and step-by-step guides in seconds with Guideflow, the leading AI-powered demo automation tool.
AI · Nov 2025 · guideflow.com
Hardware and software projects by Ali Roberts
Life & fun · Nov 2025 · bitsnpieces.dev
Welltory▲1,028Measure your wellness. Use data to feel great every day.
Work · Nov 2025 · welltory.com
TrustMRR▲833LLM Gateway is a b2b artificial intelligence based in United States, founded in 2025. $259,539/month in verified Stripe revenue. $78,764 MRR. Ahrefs Domain Rating 52/100. growing 55% month-over-month. Track LLM Gateway's verified metrics on TrustMRR.
Growth · Nov 2025 · trustmrr.com
Boing▲782Life & fun · Nov 2025 · boing.greg.technology