CO2 Room Ventilation Alert Kit with Arduino Uno + Sensor
Build a Smart CO2 Ventilation Alert System with Arduino Uno and OLED Display
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
Stale air in a closed room can cause drowsiness and poor concentration, especially in spaces like study rooms, bedrooms, or small offices. This kit lets you build a device that continuously monitors CO2 levels and automatically turns on an exhaust fan when the air gets too stuffy. With an OLED display that shows real-time readings and a warning when it’s time to ventilate, you’ll create a practical smart home tool that actually solves a daily problem.
What You'll Build
You’ll assemble a working CO2 alert system on a breadboard using the Arduino Uno, MH-Z19B sensor, and OLED module. Once built, the system will display current CO2 concentration in parts per million (ppm). When levels exceed 1000 ppm — the typical threshold for stuffy indoor air — the OLED will flash a warning and the relay will activate, switching on a connected exhaust fan to bring in fresh air. It’s a real automation project you can install in your room right away.
What You'll Learn
- How to wire the MH-Z19B NDIR CO2 sensor and read serial data from it.
- How to program the Arduino to display sensor readings on a 0.96-inch OLED screen.
- How to use a relay module to control a high-voltage appliance like an exhaust fan safely.
- How to set threshold-based alerts in Arduino code for real-world automation.
Kit Contents
| Component | Quantity |
|---|---|
| Arduino Uno R3 | x1 |
| MH-Z19B CO2 Sensor | x1 |
| 5V Relay Module | x1 |
| 0.96in OLED | x1 |
| 1N4007 Diode | x3 |
| 10kΩ Resistors | x5 |
| 400-pt Breadboard | x1 |
| M-M Wires | x20 |
| 9V Battery Snap | x1 |
Why Buy This Kit Instead of Sourcing Parts Separately
| Factor | Sourcing Separately | Compoden Kit |
|---|---|---|
| Compatibility checks | You verify every part | Pre-tested as a system |
| Build support | Forums and scattered tutorials | AI companion trained on this exact project |
| Time to first working build | Days of debugging | Hours, with step-by-step guidance |
| Shipping coordination | Multiple sellers, multiple delays | One shipment from Bengaluru in 3-5 days |
Who This Kit Is For
Ideal for CBSE Class 11-12 students exploring sensor-based automation for their physics or computer science projects. Also perfect for ATL Tinkering Lab setups where students need a guided first step into environmental monitoring. B.Tech ECE/EEE freshers at NIT, VIT, or BITS can use it to quickly prototype an air quality system without hunting for components across multiple online stores.
Built and Backed by Compoden
Every Compoden kit ships with an AI build companion trained on this exact project — accessible via a QR code on the box, with WhatsApp and email backup. We've spent 10 years building projects for makers, schools, and institutions across India. If a part fails because of a manufacturing defect, replace it free within 7 days.
What if I get stuck during the build?
Scan the QR code on the kit box to open the AI companion trained on this specific project. It will guide you step by step. If you prefer human help, WhatsApp us – our support team replies within a few hours.
Can I set the CO2 threshold to a different value, like 800 ppm?
Absolutely. The Arduino code can be modified to trigger the relay at any ppm level you choose. The AI companion will walk you through the simple code change so you can customise the alert for your room size or sensitivity needs.
Does the kit include the exhaust fan, and can I use my own?
The kit does not include an exhaust fan. The 5V relay module can switch any standard 230V AC exhaust fan (bathroom, kitchen, or window type). You just connect the fan’s live wire through the relay terminals – the kit works with what you already have at home.
Is the MH-Z19B sensor factory-calibrated, or do I need to do something special for an Indian climate?
The sensor uses automatic baseline calibration, so it adjusts itself over time in normal indoor conditions. In high-humidity Indian environments, just power it in a well-ventilated room for the first 24 hours – the sensor will then establish a reliable fresh-air reference point.
MH-Z19B CO2 above 1000ppm triggers relay exhaust fan and shows OLED warning.
What's in this kit
- Arduino Uno R3
- MH-Z19B CO2 Sensor
- 5V Relay Module
- 0.96in OLED
- 1N4007 Diode x3
- 10kΩ Resistors x5
- 400-pt Breadboard
- M-M Wires x20
- 9V Battery Snap
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Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items