Introduction
Indoor air quality isn’t just a concern for allergy sufferers—it's essential for everyone. From lingering shower humidity to VOCs from cleaning products, monitoring air quality can help you stay healthier, avoid mold, and make your smart home... well, smarter. Let’s explore how you can track your home’s air quality and trigger automations with platforms like Apple HomeKit and Home Assistant.
Why Air Quality Monitoring Matters
- Health & Comfort: High humidity can lead to mold growth. Poor air quality contributes to allergies, headaches, fatigue, and respiratory issues.
- Smart Energy Use: Avoid running air purifiers and fans unnecessarily by automating them based on real-time data.
- Peace of Mind: Whether it’s for your family, elderly loved ones, or guests with sensitivities, knowing the air is clean and safe adds a layer of comfort.
Smart Air Quality Sensors That Work with HomeKit and Home Assistant
🔹 Aqara Temperature and Humidity Sensor
- Works natively with
Home Assistant over Zigbee.
- Works with
HomeKit using the
Aqara M3 hub over Matter.
- Tracks temperature and humidity.
- Affordable and reliable.
🔹 Eve Room (HomeKit)
- Works natively with HomeKit (no hub required).
- Measures VOCs, temperature, and humidity.
- Bluetooth and Thread compatible.
🔹 Airthings View Plus
- Supports Home Assistant via integrations.
- Monitors radon, PM2.5, CO2, VOCs, humidity, and temperature.
- Great for detailed insights.
🔹 Awair Element
- Works with Home Assistant via community integrations.
- Measures temperature, humidity, CO2, VOCs, and PM2.5.
Real-World Use Case: Automating a Bathroom Fan When You Shower
A common pain point: bathrooms fog up after a hot shower and can lead to mold or peeling paint if not properly ventilated. Let’s fix that with smart tech.
🛠️ Setup for HomeKit
What you need:
- Aqara Temperature and Humidity Sensor
- Aqara M3 hub (Matter-enabled)
- A smart switch or plug for the fan (e.g., Lutron Caséta, Eve Energy)
How to:
- Add your Aqara sensor and hub to the Apple Home app.
- Add your smart plug or switch that controls the fan.
- Create an automation:
- When: Humidity rises above 70%
- Then: Turn on the bathroom fan
- Optionally: Turn off the fan when humidity drops below 60%
Note: These trigger points might need to be adjusted depending on your local weather and how hot you like your showers. In a humid climate or for cooler showers, the spike in humidity might be smaller, so you may need to use lower thresholds.
🛠️ Setup for Home Assistant
What you need:
- Aqara Temperature and Humidity Sensor (Zigbee)
- Zigbee hub (ZHA or Zigbee2MQTT)
- Smart switch or relay for the fan
How to:
- Pair the Aqara sensor in Home Assistant via Zigbee.
- Go to
Automations and create a new one:
- Trigger: Humidity goes above 70%
- Condition: (optional) Only between certain hours or when room is occupied
- Action: Turn on the fan entity
- Add a second automation to turn the fan off when humidity drops below a set level (e.g., 60%).
Example YAML for Home Assistant:
alias: Turn On Bathroom Fan When Showering
trigger:
- platform: numeric_state
entity_id: sensor.bathroom_humidity
above: 70
condition: []
action:
- service: switch.turn_on
target:
entity_id: switch.bathroom_fan
mode: single
alias: Turn Off Bathroom Fan After Shower
trigger:
- platform: numeric_state
entity_id: sensor.bathroom_humidity
below: 60
condition: []
action:
- service: switch.turn_off
target:
entity_id: switch.bathroom_fan
mode: single
Bonus Tip: Home Assistant also has a community-contributed
Blueprint called Bathroom Humidity Exhaust Fan that adds more configuration, options, and optimizations. This is highly recommended if you want a more advanced and reliable setup without writing YAML from scratch. You can find it here:
Bathroom Humidity Exhaust Fan Blueprint
Bonus Ideas for Air Quality Automations
- Run an air purifier when PM2.5 is high
- Send a notification if CO2 or VOCs spike
- Lower your shades if temperature and sun are too high
- Turn on a humidifier when air is too dry in winter
How Heritage Home Technologies Can Help
Whether you're just getting started or want to integrate whole-home air quality monitoring,
Heritage Home Technologies can guide you every step of the way. We’ll help you choose the right sensors, get them connected to Home Assistant or HomeKit, and build powerful automations tailored to your needs—especially if you’re caring for aging family members or those with special sensitivities.
