Indoor air quality is an important part of the work and study environment. The established benchmark test for indoor air quality is to assess CO2 levels. It is generally understood that indoor CO2 levels are a good proxy for the amount of pollutant dilution in occupied spaces and can therefore be used as a good indicator for fresh air.

A high level of CO2 causes headaches, sleepiness, poor concentration, and loss of attention. Regarding Covid-19, ventilation also plays an important part in reducing virus transmission by dilution and removal of infected particles and droplets.

The best way to keep the CO2-levels at an acceptable level is a well-working ventilation/HVAC-system introducing ample amounts of fresh air into the room space while simultaneously removing stale air. CO2 sensors along with temperature and humidity sensing are often used as part of automatic ventilation control systems. But what if the building or school does not have such a sophisticated environmental control setup as part of its Building Management System. Then retrofitted wireless solution is the answer.

The city of Porvoo chose battery-powered, retrofitted, low-cost IoT-sensors and connectivity from Connected Inventions/Connected Finland. Sensors are placed in city-owned schools and kindergartens as well as in some other city-owned buildings.

In addition to CO2, the hundreds of devices are measuring temperature and humidity and sending the measurements via Sigfox IoT-network into the cloud platform. They play a vital part in the energy efficiency projects brought to the City of Porvoo by Danfoss Leanheat and Porvoon Energia. The project is part of the CANEMURE-research program ran by the City of Porvoo and partially funded by the EU Life program. CANEMURE seeks to improve the energy efficiency in Finnish municipalities and counties.