EmpAIR Ventilation Advisor

We think Covid 19 transmission and air quality are strongly correlated. The EmpAIR sensors help you to monitor the air quality in your labs. It informs you when ventilation is advisable.

The leaflet explains all the details (click for download).


The video explains in 3 minutes how it works and how two use.

This system was developed in collaboration within Empa from Lab 405 and Lab 503 . It could help to limit spreading of the corona virus.

CO2 sensor information/instructions
The system measures the CO2 concentration (additionally also humidity, temperature and air pressure) in your office or meeting room. It can be assumed that the CO2 level correlates with the virus aerosol concentration in case an infected person is present. The sensor helps to indicate when the room needs to be ventilated (based on FOPH CO2 recommendations Wegleitung zu den Verordnungen 3 und 4 zum Arbeitsgesetz, Artikel 16 Raumklima)  to bring back fresh and uncontaminated air.
app color code CO2 concentration (ppm) air quality (CO2 levels)
green < 1000 good
yellow 1000-1400 moderate   Download
red 1400-2000 poor   App
red blinking > 2000 unacceptable
The sensor is battery powered (3 x AA) and should last around 2 years. Place the sensor in your room; there is a magnet in the back and holes to mount it to a vertical surface if needed. The sensor is always on and broadcasts its sensor values. They can be registred by either an Android powered device or a custom made hardware. The instructions how to get the app can be found below. Each sensor has a unique identifier lasered on top of it that helps to identify your sensor in the app.
EmpAIR Mobile App
dowload description as printable-pdf
1. How to install the app
Install the app from the Google Play Store or the Apple App Store:
Search for "EmpAIR" or use this URL:

If you do not have Google services, download this installer to your mobile phone or tablet: app.apk (latest version v0.2.1; 14.01.21)
2. How to use the app

Open home page: Cube color depends on CO2 concentration 

Open graph page: Observe the CO2 concentration over time

Open sensor list page: Select a specific sensor 1)

Open info page for settings and information
Start logging to file 2)
Stop logging
Rescan available sensors and connect to the nearest one 3)

If the app cannot find sensors and your close to one: Enable location services in general on your device 
(Settings à Security and Location à Privacy à Location à On).

Clear the graph


1) Higher RSSI means a stronger Bluetooth signal 
2) Options and file path see info page
3) Open the sensor list page to see all available sensors 

Python sample script to read sensor values

This script requires Python 3 and the bleak library (https://github.com/hbldh/bleak) and runs on PC or a Raspberry Pi. It listens to all available sensors and creates/appends a csv file for each sensor found. This is meant to be a sample program, it is not guaranteed to run properly and can be copied or changed for any purpose.

Download EmpaAIR_reader.zip

EmpAIR Windows App

The EmpAIR Windows App is an application to show the EmpAIR sensor's CO2 Value on your PC and warns you when the CO2 is increasing with a notification. The Windows App requires Bluetooth Connec-tivity (Works with the HP Empa Laptop when Bluetooth enabled). 
1. How to install the app
Use the link below to download the setup file. Once downloaded double click and install it.
EmpAIR Windows V1.5 Installer

File Size:                     ~24 MB
Version:                     1.5
File Hash:                   78C7A24EA89EEADDA79AA3B18036676A9EB345864AF643DA6C533289B962A98A

2. How to use the app
The tool automatically starts after the setup and starts automatically upon a reboot. There is an Empa Cube in your tray bar, you might have to pull it down to your bar when hidden with the small arrow.
Right click on the cube 'Select sensor ->' and select the sensor you have in your office and want to have displayed. The cube then soon changed the color depending on the current CO2 value the sensor measures. If you have no sensor to select, make sure you have Bluetooth enabled and that there is a sensor nearby. The tool remembers which sensor was selected last when restarted.
Now when the CO2 level gets worse the cube changes colors and there is a windows notification visible on the bottom right of your screen.

Multiple EmpAIR assess the change of the air quality during a ride