On November 19^th, 2024, representatives from the building cooling and ventilation associated industry together with architects, and consultants gathered for the 10^th meeting of the Advisory Board of Practitioners (ABoP). This board, led since the beginning of 2024 by venticool (and initially run in conjunction with Annex 80 from 2021 to 2023), was founded to put results of scientific research into action by establishing strong ties to practitioners and to include their practical experience and feedback in future research projects.

17 participants attended the meeting which focused on the “Hybrid cooling: how to design and operate?”. Following a short introduction & welcome speech by Hilde Breesch (KU Leuven Belgium), there were 2 presentations by experts. The first presentation by Peter Holzer (Institute of Building Research & Innovation, Austria) focused on “Hybrid cooling: interesting approaches”. Ongun Berk Kazanci (DTU Denmark) then presented “Comfort-based control for mixed-mode buildings/hybrid cooling”.

Following the 2 presentations, the participants were split into 2 break-out sessions to discuss the questions which follow:

1. Would you consider applying micro cooling for residential buildings in your country? Why or why not?
2. Would you consider applying “hidden” cooling in buildings? Why or why not?
3. What are in your opinion the challenges for the control of hybrid cooling/mixed mode buildings?
4. Do you believe that climate change has affected the building users’ expectations for thermal comfort? Please explain your reasoning. 

The majority expressed a willingness to consider applying micro cooling solutions for residential buildings in their countries. However, they also raised concerns that residents in moderate climates might opt for full air conditioning systems instead. Additionally, there was a general consensus that “hidden” cooling is an appealing concept, though some participants raised doubts about whether it could guarantee thermal comfort.

The key challenges identified for controlling hybrid cooling or mixed-mode buildings include balancing automation with user preferences, accommodating varying comfort expectations, and addressing diverse room uses and occupant needs. Effective control must integrate parameters like temperature, humidity, noise, outdoor air quality, etc. while managing the complexities of switching between windows opening and mechanical cooling.

In response to whether climate change has affected building users’ expectations for thermal comfort, it was noted that expectations align with the mindset that slightly elevated indoor temperatures are acceptable during extreme heat. In addition, an increase in demand for mechanical cooling is anticipated, driven by easy accessibility to AC and the appeal of combining PV systems with heat pumps, particularly in regions with high electricity prices.

Next meetings

• Meeting #11: 27 March 2025 
• Meeting topic: Exact topic soon to be announced

If you are interested to join the board, please contact Maria Kapsalaki.