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Installation Case: Building Carbon Capture with HVAC Integrated Direct Air Capture Unit at Wärtsilä Sustainable Technology Hub, Vaasa, Finland

Installation Case: Building-HVAC-Integrated Direct Air Capture Unit (2023)

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The Client:

Wärtsila, a global leader in innovative technologies and lifecycle solutions for the marine and energy markets and listed as one of TIME’s 100 Most Influential Companies In The World 2023. Our system has been installed in Wärtsilä Sustainable Technology Hub in Vaasa, Finland.


The company itself.


As the global population gravitates towards urban centers, CO2 emissions surge, impacting indoor air quality. High indoor CO2 is associated with dizziness, fatigue, and reduced cognitive function scores, as demonstrated by Harvard research. Addressing this challenge necessitates innovative approaches that go beyond conventional ventilation strategies. Although the solution might appear straightforward – simply opening windows for ventilation – this proves impractical within enclosed office buildings.

CO2 affects your cognitive functions


The following challenges were there:

  1. Limited Ventilation Options: Opening windows in modern office buildings is often unfeasible, posing difficulties in maintaining optimal indoor air quality.
  2. Escalating CO2 Levels: The surge in urbanization exacerbates CO2 concentration indoors, leading to health concerns and decreased cognitive function.
  3. Need for Sustainable Solutions: The clients sought eco-conscious remedies that align with their commitment to sustainability.
  4. Practical Integration: Integrating carbon capture technology without disrupting building design and operations was a primary concern.
  5. Onsite CO2 Capture System Deployment: Wärtsilä needed a carbon dioxide-capturing system of their own.


Soletair Power installed the HVAC Integrated Direct Air Capture (DAC) Unit and added CO2 capture capability.

By incorporating proprietary sorbents, Soletair Power unit first adsorbs CO2 from the incoming air. Upon saturation, a regeneration process— utilizing vacuum and heat — collects and stores the captured CO2 inside a container near the building.

This integration within the existing HVAC infrastructure ensured functionality without compromising architectural aesthetics.

Soletair Power Buildings as Carbon Sinks Wartsila Unit


Wärtsilä STH, Finland
Machines inside a building HVAC room

CO2 is captured from incoming air

in the HVAC room
Black colored Tank for storing CO2

Captured CO2 is stored

In a tank placed outside the building

Technical Specifications of the Unit:

  • Dimensions: 3m x 3m x 3m (L x W x H)
  • Capture Capacity: 50 kg/day
  • Sorbent Filters: Proprietary amine-functionalized solid sorbents that adsorb CO2 selectively.
  • Regeneration Process: Temperature Vacuum Swing Adsorption (TVSA)
  • Integration: Compatible with IoT sensors and building automation systems.
Process illustration of building carbon capture

Key Benefits:

The HVAC Integrated DAC Unit offers a range of advantages:

  • Enhanced Indoor Air Quality: Effective CO2 capture ensures healthier indoor environments, improving employee well-being and cognitive function.
  • Energy Efficiency: Dynamic ventilation runtime control reduces HVAC energy costs, optimizing energy consumption and operational efficiency.
  • Versatility: Modular design and IoT compatibility allow for easy installation, integration with building automation systems, and potential CO2 utilization in various applications.
  • Sustainability: The project aligns with environmental goals by reducing carbon footprints, and promoting sustainable urban development.
Hannu Mäntymaa and Jukka Rapo presenting the Soletair Power Building Integrated CO2 capture unit at Wartsila STH Vaasa Finland

CO2 Storgae:

In Vaasa, we have a 3.6 cubic meter tank, which is stationary. The ZBT and Vantaa installations have a 12-bottle bundle (, which can be easily transported to another site with a truck. The bundle has 360kg of CO2 when it is at 200 bar. Achieving 200 bar requires a compressor capable of doing so, but it is possible with the correct compressor.

For more information about this HVAC Integrated Direct Air Capture Unit, please visit

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