Decarbonized, healthy, and energy-conscious buildings in future climates

The REHVA HVAC World Congress CLIMA is the leading international scientific congress in the field of heating, ventilation, and air conditioning (HVAC). After the great success of the 2022 edition, organized by the Dutch association TVVL, the baton now passes to AiCARR for the organization of CLIMA 2025: the 15th REHVA HVAC World Congress, which will be held in Milan, Italy, from June 4th to 6th, 2025. The theme of this Italian edition is "Decarbonized, healthy, and energy-conscious buildings in future climates", a topic that highlights the fundamental importance of the HVAC sector in all its aspects. In this perspective, CLIMA 2025 will offer professionals, academics, and companies in the HVAC sector a unique opportunity for international discussion about these "hot" subjects.

morE infoRMAtion and tickets 

This year, the REHVA Student Competition will be held during the REHVA HVAC World Congress CLIMA (4-5 June 2025)! Discover the rules here. 

REHVA technical workshops

REHVA is hosting technical workshops at CLIMA 2025 to advance and share the most reliable knowledge in the HVAC field. To achieve this, REHVA is collaborating with a diverse range of partners. Click HERE to see the full list and agenda. 

REHVA workshops with international partners

REHVA - ISHRAE: Indoor climate targets and design requirements in Indian and European education buildings

4th June 14:00 - 15:30

Poor indoor air quality in schools is a growing concern, with inadequate ventilation, exposure to outdoor pollutants, and thermal discomfort affecting students' well-being and performance. While energy efficiency in buildings has been prioritized in recent years, it has sometimes come at the cost of indoor environmental quality.

This workshop will explore the challenges of balancing energy efficiency with a healthy indoor climate in educational buildings. Participants will discuss strategies to improve IAQ, thermal comfort, and overall environmental conditions while maintaining sustainable energy use.

REHVA - CAHVAC: Healthy Sustainable Buildings in Europe and China

5th June 14:00 - 15:30

This workshop explores the integration of innovative HVAC technologies and sustainable building solutions, drawing from collaborative research by REHVA and CAHVAC. Presentations will address emerging challenges in energy efficiency, indoor environmental quality, and the health impacts of building designs.

Discussions will focus on multidisciplinary approaches and cutting-edge methodologies for optimizing HVAC systems. Experts will present insights into advanced energy performance assessments, case studies, and strategies to enhance both sustainability and occupant well-being. The session aims to foster knowledge exchange and collaboration among researchers, practitioners, and policymakers.

REHVA - SHASE: Introduction of Joint position document by REHVA (EU) and SHASE (Japan) and ZEB case studies

4th June 16:00 - 17:30

This workshop presents findings from a joint study by SHASE and REHVA on the definitions and calculation methods for Zero Energy and Zero Emission Buildings. Experts will discuss the latest updates following the 2024 EPBD revision and Japan's ZEB framework.

Key topics include energy performance assessments, results from model energy simulations in three European climates for ZEB apartments, and evaluations of office buildings in Japan. Additionally, the workshop will explore HVAC system comparisons, analyzing thermal comfort, air quality, and energy performance to determine the most efficient solutions for ZEBs.

REHVA workshop on IEQ in EPBD, by REHVA TRC

5th June 10:15 - 11:45

Long term assessment by simulation or monitoring, labels and regulation

The 2024 recast of the Energy Performance of Buildings Directive introduces significant new requirements for indoor environmental quality, setting a new standard for national regulations. This workshop will explore key changes, including the principle of optimal IEQ, the establishment of national IEQ requirements, and the mandatory integration of indoor air quality monitoring and regulation devices in new non-residential buildings.

Discussions will focus on the growing need for demand-controlled ventilation systems, which will become essential from 2028/2030, and the challenges of ensuring their long-term performance. With continuous monitoring generating vast amounts of data, we will examine tools and methodologies for assessing IAQ and thermal comfort, optimizing system operation, and improving occupant well-being.

REHVA Workshop by EUPAG

6th June 14:00 - 15:30

Driving change: turning technical expertise into actionable policy input

This workshop will highlight how REHVA actively contributes to EU policy shaping by turning technical expertise into actionable policy input. The REHVA EU Policy Advocacy Group (EU PAG) plays a central role in this process, acting as a bridge between REHVA’s technical work and the European Commission’s policymaking.
REHVA’s technical content, developed within its Task Forces in the framework of the Technology and Research Committee (TRC), is regularly transformed into policy messages and recommendations. These are delivered to the European Commission through the EU PAG, with the active support of REHVA’s member associations and corporate Supporters, ensuring a well-rounded, practice-based contribution to the regulatory debate. 

This collaborative process has led to concrete input into key EU initiatives, notably the implementation of the Energy Performance of Buildings Directive (EPBD).
To complement this point, REHVA supporters will intervene as speakers and panellists, to highlight the specific perspective of an industrial association and/or a company, their necessities related to EU policies and why, from their perspective, it is an added value to pursue policy-advocacy goals within the REHVA umbrella
The workshop will also present the REHVA Manifesto, our strategic roadmap aligning with EU climate goals and calling for healthier, decarbonised and energy-efficient buildings. In doing so, REHVA brings together building designers, engineers and installers with companies and industrial associations to pursue shared goals. 
With no one-size-fits-all solution, REHVA continues to champion a holistic, cross-sectoral approach to drive meaningful change in Europe’s built environment.

Workshop by REHVA Supporter Spacecool

5th June 16:30 - 18:00

Cooling without Energy Consumption - Introduction to Passive Radiative Cooling & Novel Cooling Systems based on it

The year 2024 was the hottest recorded ever in Europe while according to the IEA the electrical energy consumption for surged to nearly double the annual average over the past decade. One of the main drivers for this increase was energy needed for cooling. Just a decade ago, in 2014 Prof. Raman of the University of Stanford published a paper on a natural phenomenon called Passive Radiative Cooling (PRC). An effect which allows surfaces to cool down below ambient temperature even in bright sunlight.  Although it is a phenomenon observed and even used by mankind over centuries, his paper for the first time explained the physics behind it in detail. It also led to the creation of products, making this effect usable for cooling of objects. Although the initial paper has been published a decade ago, it still is far away from being commonly known. Accordingly, PRC materials are not at all commonly used or even known in the relevant industries.

In this workshop we will introduce into the phenomenon of PRC. Its physics will be explained and also a view on the actual state of research. This will include a peek onto the currently conducted Parametric project, which aims at defining standard measurement methods and is conducted by the meteorological scientific community of the EU.  We will also illustrate how the phenomenon was transformed into a product that can be widely adopted to relevant industries. We will illustrate how and where it is already successfully applied. We would like to take three steps with the audience. In the first step we will show the application and the effect of passive radiative cooling to surfaces. This includes buildings and installations, where the PRC effect can lead to avoiding the use of active cooling means. In the next step, we would like to illustrate and discuss combination of PRC with active cooling means. There are various ways of applying it to or combine it with HVAC systems in order to reduce energy consumption, increase performance and reduce failure. Most of the cases discussed will be based on a retrofit application.

In the workshop we would like to encourage and discuss the potential of applying PRC materials initially at the design stage to HVAC systems. This will lead to the last step: the combination of the radiative cooling material from SPACECOOL with a radiant cooling system for indoor cooling. This innovative approach which has been realized and tested in summer 2024 in Spain will serve as an example how sustainable cooling innovation is possible based on PRC and can lead to sustainable product innovation.
An active involvement of the audience will be very much appreciated and encouraged over the whole course of the workshop. In the closing discussion space for feedback will be given while aiming ideally at the creation of workgroups spinning off from the workshop. Ideas for further research and product creation will be shared. 
 

Workshops by EU Projects

Energate & Moderate: Facilitating energy efficiency in buildings: smart solutions for real estate, energy service companies and financiers

5th June 11:30 - 13:00

The building sector is a significant contributor to global energy consum-ption and greenhouse gas emissions, accounting for approximately 36% of energy use worldwide. Despite the vast potential for energy efficiency improvements in building renovations, progress remains limited. Challenges include high upfront costs, complex regulatory requirements, and often lengthy return-on-investment periods, which deter many property owners. Additionally, awareness and access to information about available financial incentives and technical solutions are frequently insufficient. Overcoming these barriers requires streamlined financing options, more accessible policy frameworks, and broader awareness of the long-term cost savings and environmental benefits of energy-efficient renovations.

Given the urgent need for energy efficiency improvements to meet climate goals, it is crucial to harness new and innovative technologies that make buildings more sustainable, smarter, and cost-effective.

This workshop will be an opportunity for the MODERATE and ENERGATE projects to share insights, technologies, and best practices, as well as to explore synergies. The event will serve as a platform for stakeholders to discuss the barriers, opportunities, and actionable strategies for advancing energy efficiency in buildings using smart technology and innovative financial models.

Funded by the European Union

SmartSquare: Advancing SRI Implementation: Connecting EPBD provisions and regional adoption with project outcomes

6th June 10:15 - 11:45

The workshop will focus on discussing the project’s Key Exploitable Results (KERs) and their contribution to the Smart Readiness Indicator (SRI) implementation. It will connect the project's outcomes with EU plans and explore the necessary steps to advance SRI adoption at regional and national levels. This will be supported by real case studies, showcasing the impact and opportunities from technical and market perspectives, particularly in design consulting and support services.

Funded by the European Union

Next Gen EPC cluster (tunES, SmarterEPC and iEPB projects): Practical Pathways to EPBD IV Implementation

5th June 16:00 - 17:30

This workshop, convened by the EPB Center and the Next Gen EPC cluster of EU funded project, explores how innovative policy implementation approaches and digital & technical solutions are facilitating practical EPBD IV implementation across the European Union. The session brings together representatives of the European Commission (DG ENER, CINEA), national authorities (e.g., ENEA Italy), and key EU funded projects, tunES, SmarterEPC and iEPB, to showcase how a new wave of EPC/SRI tools, data models, and auditing methods are enabling convergence with the EPBD IV provisions and guidance. Each project contributes with a unique technical focus: from innovative policy training, implementation and compliance tools (tunES) to harmonised onsite audits and joint EPC+SRI certificates (SmarterEPC), and to integrated data structures and calculation engines (iEPB).

The workshop will conclude with an interactive panel discussion, providing a space for critical insights and suggestions from EU officials, lessons learned from the EU project teams and the broader HVAC and building performance community. By weaving together policy, practice, and innovation, this session aims to help stakeholders navigate the EPBD IV rollout with actionable insights and collaborative pathways forward.

tunES, SmarterEPC and iEPB projects have received funding from the European Union’s LIFE Clean Energy Transition subprogramme.