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Other Materials - Beyond the Tool and the Hub

Introduction

Throughout the project, valuable knowledge has been generated beyond the development of the tool and hub, offering insights that can be applied for various purposes. This page provides a concise overview of these resources, each referring to relevant deliverables for further details. The topics covered include:

The following sections present brief overviews of each topic, with links to relevant deliverables for a more comprehensive understanding.

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Overview of cooling technologies

An overview of current and future space cooling (SC) technologies to address Europe’s growing cooling needs was conducted. As a result, the taxonomy of SC technologies was created and can be viewed in Figure Taxonomy of Space Cooling Technologies) below. The technologies were categorized using multiple parameters, including:

  • physical energy form (electrical, mechanical, acoustic, magnetic, chemical, thermal, and natural)
  • operating principle
  • refrigerant/heat transfer medium, working fluid phase (single-phase, two-phase, or no phase change)
  • technology type (active, passive, or both)
  • fuel type (including renewable energy)
  • Technology Readiness Level (TRL).

The review classified SC technologies into conventional vapour compression (VC) systems 35 alternative technologies, including magnetocaloric, thermoacoustic, thermoelastic, thermoelectric, desiccant cooling, and membrane heat pumps. Special consideration was given to technologies capable of integration with renewable energy sources, as well as their efficiency (seasonal energy efficiency ratio – SEER), lifecycle costs (CAPEX, OPEX), environmental impacts, and sector-specific applications.

The detailed overview can be accessed in the deliverable D2.1 “Taxonomy of space cooling technologies and measures” (Duplessis et al, 2023). The report assesses various space cooling (SC) technologies currently available on the market, as well as emerging technologies with potential future applications.

Figure Taxonomy of Space Cooling Technologies sc_tech

The key findings with regards to SC technologies are as follows.

  • Vapour Compression (VC) Systems, including split systems, VRF systems, rooftop units, and chillers, meet nearly 99% of Europe’s space cooling demand due to their scalability, efficiency, and mature technology (TRL 9).
  • Thirty-five Alternative technologies, including thermoelectric, magnetocaloric, and desiccant cooling, offer higher energy efficiency but are limited by cost and scalability. Most are in early development stages (TRL 2-4), except transcritical CO2 cycles and absorption systems (TRL 4-9).
  • Cost-Benefit and Scalability Considerations: VRF systems are preferred in dense urban areas due to lower noise and heat emissions, despite higher costs. District cooling networks offer long-term benefits in high-demand areas, while portable air conditioners are least efficient and noisiest.
  • Environmental and Regulatory Impact: Climate conditions and regulations promoting low-GWP refrigerants favour advanced technologies like CO2 cycles and magnetocaloric cooling, improving their cost-effectiveness in hotter regions.
  • Selection for CoolLIFE Project: Four technologies were selected for further consideration: split systems, VRF systems, district cooling networks, and portable air conditioners. Their high TRL and market readiness make them viable solutions for different building types and climates.

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Overview of cooling measures

A comprehensive review of existing measures to reduce space cooling (SC) demand was conducted, with detailed results available in the deliverable D2.1 “Taxonomy of space cooling technologies and measures” (Duplessis et al, 2023). Identified measures were classified into three main categories:

  • Passive measures: do not require energy input (e.g., shading devices, ventilative cooling, and nature-based solutions).
  • Active measures: use energy to control indoor environments (e.g., smart glazing systems, adaptive facades, and ceiling fans).
  • Comfort lifestyle and user behaviour measures: include occupant actions and adaptive behaviours to maintain thermal comfort.

Active and passive measures were further categorized based on their effects, such as reducing heat gains, enhancing personal comfort, removing sensible heat, and controlling indoor humidity. In total, 56 measures were classified: 28 passive, 13 active, and 15 lifestyle and behavioural measures.

Key Findings:

  • Passive measures, such as shading devices, ventilative cooling, and thermal energy storage systems, are energy-efficient and applicable at both building and neighbourhood scales. Their effectiveness depends on building design, orientation, and climate conditions.
  • Active measures, including ceiling fans, smart glazing systems, and adaptive facades, effectively reduce cooling demand but require energy input, with efficiency varying based on technology type and application scale.
  • Behavioural adaptations involve personal and environmental adjustments, while physiological and psychological adaptations enable individuals to maintain comfort without mechanical cooling, often reducing energy demand without direct costs.
  • The effectiveness of behavioural measures is influenced by building design, occupant habits, and contextual factors, with interventions like information provision, feedback, and monetary incentives encouraging energy-saving actions.
  • The classification of measures into passive, active, and behavioural categories provides a foundation for selecting cost-effective and sustainable solutions tailored to different building types, climates, and user needs, supporting both short- and long-term cooling demand reduction.

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Summary of current and projected cooling demand

A comprehensive assessment of space cooling (SC) demand in the European Union (EU27) was conducted using 2021 as a baseline, covering both the residential and service sectors. The complete dataset, including country-level breakdowns and technology-specific consumption figures, is available in Deliverable D2.2 “Energy Demand Assessment” (Duplessis et al, 2024).

The study quantified energy demand by technology type, sector, and country, revealing that total space cooling demand across both sectors amounted to approximately 545.51 TWh/year. This demand is evenly split between room air conditioners (RACs) and centralized air conditioners (CACs), each accounting for roughly 50% of the total.

In the residential sector, RACs dominate, representing over 90% of energy consumption. The most energy-demanding technologies are small split systems (<5 kW), with an annual demand of 59 TWh/year, followed by big split systems (>5 kW, including ducted systems) at 49 TWh/year and movables at 6 TWh/year. Chillers and VRF systems contribute marginally to residential demand. Five countries—Italy, Spain, Greece, Germany, and France—account for more than 90% of total residential SC demand.

In the service sector, CACs account for 60% of demand, with big split systems (>5 kW) consuming the most energy at 140 TWh/year. Rooftop and packaged units follow at 96 TWh/year, while variable refrigerant flow (VRF) systems consume over 52 TWh/year. Air-to-water and water-to-water chillers also contribute significantly. Again, Spain, France, Italy, Greece, and Germany collectively account for over 80% of service sector demand.

Overall, big split systems (>5 kW) are the most energy-intensive, consuming 188.75 TWh/year across both sectors.

The study found that space cooling demand is concentrated in Southern and Western Europe due to warmer climates and higher population densities.

Projections indicate that rising temperatures, changing building designs, and increased demand for thermal comfort will drive future growth in cooling demand, with climate change expected to further intensify demand in southern regions.

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Overview of potential impact of different measures

A comprehensive impact assessment was conducted to evaluate the environmental, economic, and social effects of space cooling (SC) measures in the EU-27. The study explored the potential benefits of combining passive measures and improvements in active cooling technologies, using different scenarios to estimate energy savings, greenhouse gas (GHG) emissions reduction, and socio-economic benefits up to 2050. Detailed results and scenario analyses are available in Deliverable D2.3 “Impact Assessment” (Malla et al, 2024).

Key Findings:

  • Energy Savings: Combining high-efficiency passive measures with advanced cooling technologies can reduce energy consumption by up to 55% by 2030 and nearly 80% by 2050 compared to the baseline scenario. The non-residential sector benefits more from these measures due to its higher baseline energy demand.
  • Environmental Impact: CO₂ emissions could be reduced by up to 45.5% by 2030 and 80% by 2050 compared to the baseline, supporting the EU’s net-zero emission target. NOx emissions also decline due to lower electricity consumption, improving air quality.
  • Economic Impact: Implementing passive and active measures could increase the EU-27 GDP by approximately €6 billion annually until 2050. Investments in energy efficiency improvements are projected to generate between 124,000 and 300,000 full-time jobs annually.
  • Social Impact: Improved air quality due to reduced electricity consumption could prevent around 145 premature deaths annually and avoid 36,600 lost working days by 2050. Enhanced thermal comfort, particularly during heatwaves, contributes to better health, productivity, and overall well-being.

Policy Recommendations:

  • Financial incentives should be provided to encourage the adoption of passive measures.
  • Regulations should promote the diffusion of advanced cooling technologies and set stricter energy efficiency standards.
  • Public awareness campaigns can foster energy-saving behaviours, while flexible regulatory frameworks can accommodate future advancements.

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This analysis examined the concept of thermal comfort and the preferred indoor temperatures of residential building occupants, considering both standardised criteria and sociocultural influences. Using a literature review and a survey conducted in Hungary, the study explored preferences, behavioural patterns, and factors affecting thermal comfort. For detailed data, refer to Deliverable D3.1 “Knowledgebase for Occupant-Centric Space Cooling” (Hurtado-Verazaín et al, 2023).

Key Findings:

  • Thermal Comfort Standards: Recommended indoor summer temperatures range from 23°C to 26°C, with adaptive models allowing warmer limits in naturally ventilated buildings.
  • Sociocultural Influences: Growing AC use has shifted preferences toward cooler environments, reducing tolerance for higher temperatures.
  • Survey Insights (Hungary): Most respondents set AC systems between 22°C and 25°C, with an average of 23°C. Around 20% were comfortable at 28°C during the day. Common cooling behaviours included using lighter clothing (97%), opening windows (86%), and shading devices (83%).
  • Adaptive Behaviours: Personal control over indoor environments, such as window operation and fan use, significantly enhances thermal comfort.

The findings highlight that comfort preferences are individual and context-dependent, requiring flexible cooling solutions that balance energy efficiency and occupant satisfaction.

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Overview of user behaviour interventions

Compilation of behavioural and lifestyle interventions adopted by building occupants to reduce SC needs and adapt to thermal discomfort was created within this project. The analysis distinguishes between bottom-up behaviours, driven by occupants’ actions, and top-down interventions, initiated through policies, financial incentives, and social influences. The study covers residential, office, and educational buildings, where behavioural changes have the highest potential to reduce SC demand. For detailed examples and case studies, refer to Deliverable D3.2 “Analysis of Behavioural Interventions Across Europe” (Gelesz et al, 2024)

Key Findings:

  • Bottom-Up Behaviours:
    • Occupants influence SC demand through equipment use, cooling set-point preferences, window opening, and shading control.
    • Behavioural patterns vary by building type: residential users have the most control, while office and educational building occupants have limited autonomy, often relying on collective decisions.
    • Adaptation strategies, such as using fans, wearing lighter clothing, and natural ventilation, can reduce SC needs, particularly in naturally ventilated buildings.
  • Top-Down Interventions:
    • Monetary Incentives: Dynamic pricing (e.g., time-of-use tariffs and real-time pricing) encourages shifting energy use away from peak periods, reducing grid demand and SC costs.
    • Information Provision: Providing feedback on energy consumption, efficiency tips, and health impacts during heatwaves helps occupants adopt energy-saving behaviours. Personalised feedback (e.g., on energy bills or through smart home systems) is particularly effective.
    • Nudges: Social comparisons (e.g., comparing household energy use with neighbours), default thermostat settings, and gamification techniques promote energy-efficient behaviours. For example, setting higher default cooling set-points can reduce energy use without compromising comfort.
  • Building-Specific Interventions:
    • Residential: Interventions like promoting night-time ventilation, outdoor cooking, and limiting heat-generating equipment can reduce internal heat loads.
    • Offices: Relaxing dress codes during summer (e.g., “CoolBiz” initiatives), allowing flexible work hours to avoid peak heat periods, and providing real-time feedback on energy use can reduce SC demand.
    • Educational: Scheduling changes, such as shifting school start dates to cooler periods and using outdoor spaces, help reduce cooling needs during peak summer months.

Policy Recommendations:

  • Develop region-specific occupancy profiles to improve energy demand modelling.
  • Promote behavioural interventions alongside energy-efficient technologies for maximum impact.
  • Provide clear, actionable information on energy-saving behaviours, emphasising both cost savings and health benefits.

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Quantification of occupant behaviour effect on space cooling demand

Quantification of how occupant behaviour influences space cooling (SC) energy consumption in both residential and non-residential buildings was delivered by the project. Detailed data and simulation methodologies are available in Deliverable D3.3 “Multiple Socioeconomic Impacts of Sustainable Space Cooling” (Caballero et al, 2024). Using building energy simulations, the study assessed the impact of occupant presence, window use, shading, cooling setpoints, and internal heat loads on SC demand. Three behavioural profiles were analysed:

  • Unconscious (relying on mechanical cooling)
  • Mitigative (using passive and adaptive measures in response to discomfort)
  • Adaptive (preventing discomfort through proactive measures).

Key Findings:

  • Residential Buildings:
    • Behavioural measures can reduce SC demand by up to 97-100% in the Adaptive scenario and by 69-84% in the Mitigative scenario compared to the Unconscious profile.
    • Reducing internal heat loads from 10 W/m² to 4 W/m² and limiting appliance usage achieved the largest energy savings, reducing SC demand by nearly 20 kWh/m²/year.
    • Conscious shading behaviour decreased SC demand by 10 kWh/m²/year (Italian multifamily house case study). Night ventilation further reduced demand by 5 kWh/m²/year.
  • Non-Residential Buildings:
    • Behavioural measures reduced SC demand by 40-76% across hospitals, hotels, educational buildings, and offices, with the highest savings in offices.
    • Increasing cooling setpoints by 1°C lowered annual SC demand by 0.5-12 kWh/m²/year, reducing demand by 5-68% depending on the building type and scenario.
    • Shading reduced SC demand by 39% on average in offices, with potential savings ranging from 6-65% depending on orientation and location.
    • Night ventilation significantly reduced demand, particularly in educational and office buildings.
  • Climate and Building Envelope Effects:
    • Climate change will increase SC demand, but the rise is largest in the Unconscious scenario (4.10 kWh/m²/year on average). Adaptive behaviour significantly mitigates this increase.
    • Improved building envelopes do not always reduce SC demand, especially if not paired with adaptive occupant behaviour.
  • Social and Environmental Benefits:
    • Reducing SC demand through behavioural measures can lower electricity consumption by 12% in the residential sector and 6-15% in non-residential subsectors.
    • This reduction could prevent 15 premature deaths annually due to air pollution and save 4,284 lost working days in the EU-27.
    • Increasing setpoints and reducing electricity use also contribute to lower emissions and improved air quality.

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Summary of current EU-level legislation and Member States' policies relevant to sustainable space cooling

A summary of key European Union (EU) regulations and national policies related to sustainable space cooling (SC) was done within the project. The review covers EU directives, adaptation strategies, and national building regulations, highlighting both advancements and gaps in promoting energy-efficient cooling solutions. Detailed information and country-specific regulations are available in Deliverable D4.1 “Review and Mapping of Legislations and Regulations on Sustainable Space Cooling at EU and National Levels” (Broc et al, 2024).

Key Findings:

  • EU Legislation:
    • The Energy Efficiency Directive (EED) and Energy Performance of Buildings Directive (EPBD) mandate improving building energy performance, including cooling, with specific provisions for reducing overheating and promoting passive measures.
    • The Renewable Energy Directive (RED) aims to increase the share of renewable energy in cooling systems, while the Ecodesign for Sustainable Products Regulation (ESPR) sets energy efficiency standards for cooling products.
    • The Fluorinated Greenhouse Gases (F-gas) Regulation phases down high-GWP refrigerants, encouraging the use of climate-friendly alternatives.
    • The EU’s Climate Adaptation Strategy promotes measures like green roofs and urban shading to mitigate heatwaves, while the Fit for 55 Package reinforces these initiatives with more ambitious energy efficiency targets.
  • National Regulations:
    • All Member States integrate space cooling into energy performance calculations, but only some set explicit limits for cooling demand or address summer comfort.
    • Countries like Austria, Croatia, and France have specific provisions to limit overheating and promote passive cooling. For example, Austria sets a maximum cooling energy limit of 1 kWh/m²/year for new buildings, while France’s RE 2020 regulation incorporates adaptive comfort models.
    • Indoor temperature limits typically range from 26°C to 28°C for residential buildings, with slightly lower thresholds for non-residential spaces.
    • Cooling system efficiency requirements are often included in building codes, especially for new constructions and major renovations.
    • National Adaptation Strategies (NAS) and National Adaptation Plans (NAP) increasingly address the impact of heatwaves, with measures like urban green spaces, reflective materials, and improved ventilation. However, integration with energy policies remains limited in most countries.

Policy Gaps and Recommendations: - Space cooling is still primarily addressed as a technological issue, with insufficient emphasis on reducing cooling demand through building design and occupant behaviour. - Greater coordination between EU, national, and local policies is needed to promote climate-resilient building design and urban planning. - Financial incentives and regulatory measures should prioritise passive cooling and energy-efficient technologies to reduce reliance on mechanical cooling systems.

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Overview of current financing schemes for cooling

This section summarises available financing schemes supporting sustainable space cooling (SC) at both EU and national levels. The analysis covers public and private funding options aimed at improving building energy efficiency, promoting renewable energy for heating and cooling (H&C), and supporting district heating and cooling (DHC) networks. For further details, refer to Deliverable D4.2 “Review of Financing Schemes Relevant for Sustainable Space Cooling at EU and National Levels” Conforto et al, 2024.

Key Findings:

  • Funding Availability:
    • A total of 556 financing schemes were identified across EU-27, with 350 public and 206 private schemes. Public funding is more prevalent, reflecting government efforts to address high initial costs and long payback periods.
    • Public schemes mainly offer grants (51%), loans (14%), and tax incentives (8%), while private schemes focus on green loans (57%), green mortgages (22%), and green bonds (7%).
  • Target Sectors and Scope:
    • 71% of schemes target residential buildings, while 49% focus on non-residential premises.
    • 53% of schemes specifically address space cooling, but often jointly with heating.
    • Funding is more accessible for building envelope efficiency (82%), H&C efficiency (84%), and renewable energy systems (77%), with fewer schemes for district cooling (33%).
  • Geographical Disparities:
    • Countries with the highest number of schemes include Germany (48), France (46), Poland (36), Austria (33), and Belgium (32).
    • Cooling-specific schemes are inconsistently available in countries with high Cooling Degree Days (CDD), such as Spain (5) and Malta (5), while Portugal (16) and Cyprus (12) offer more comprehensive support.
  • Barriers and Challenges:
    • Cooling is still often perceived as a luxury rather than a necessity, limiting the availability of dedicated funding schemes.
    • Fragmented information and rapid changes in funding programs create obstacles to accessing financing, particularly for smaller projects.
    • The financial sector favours traditional instruments, raising questions about the scalability of innovative financing approaches.
  • Expert Insights:
    • Interviews with H&C experts highlight the need to address cooling as an essential component of building energy performance, especially for vulnerable populations and productivity in commercial spaces.
    • Simplified access to financing, better awareness of available schemes, and improved coordination between EU, national, and local policies are key to closing the investment gap.

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Geoscientific datasets for investment decision support and strategic planning of 5GDHC

This section provides an overview of geoscientific datasets and mapping tools that support investment decisions and strategic planning for 5th Generation District Heating and Cooling (5GDHC) networks. The focus is on tools that visualise energy consumption, renewable energy availability, and potential thermal energy reuse, helping urban planners, policymakers, and investors design cost-effective and sustainable heating and cooling networks.

Types of Tools:

  • A total of 16 tools were analysed, including 11 open-source and 5 commercial tools, covering energy consumption, emissions, costs, and district network simulations.
  • Open-source tools such as HotMaps Toolbox, Planheat, Thermos, and Heat Roadmap Europe 4 (HRE4) provide accessible platforms for energy demand assessment and future scenario simulations.
  • Commercial tools like Invert/EE-Lab and SimStadt offer advanced modelling capabilities, integrating real-world urban data for detailed energy scenarios.

Geoscientific Datasets:

  • Tools use datasets that include building geometry, energy consumption patterns, climate data, and renewable energy availability (solar, geothermal, and industrial waste heat).
  • For district cooling planning, datasets highlight potential sources of excess heat and cooling, such as lakes, rivers, and industrial processes.
  • Geographic Information Systems (GIS) are integrated into platforms like EMB3Rs and CitySim Pro to visualise spatial energy flows, supporting the optimal placement of 5GDHC networks.

Energy Demand Modelling:

  • Tools use both top-down (macro-level trends) and bottom-up (building-level data) approaches to estimate space heating and cooling demand, accounting for building characteristics, occupancy, and climate impacts.
  • City Energy Analyst (CEA) and EnergyPlus simulate energy consumption and CO₂ emissions at the neighbourhood and city scales, while IDA ICE evaluates building performance with dynamic simulations.

Decision Support for 5GDHC:

  • Tools like Thermos and Heat Roadmap Europe 4 help identify optimal locations for district cooling networks, considering population density, infrastructure costs, and environmental impact.
  • EMB3Rs assesses the techno-economic feasibility of reusing industrial excess heat and cooling for 5GDHC, improving energy efficiency and reducing CO₂ emissions.

User Feedback and Challenges:

  • User feedback highlights the need for improved data accuracy, easier integration of local datasets, and better visualisation of energy scenarios.
  • Limited availability of high-resolution cooling demand data remains a challenge, especially in regions with emerging cooling needs.

These tools and datasets provide essential support for planning 5GDHC networks, helping cities transition to low-carbon heating and cooling systems.

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How To Cite

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Ardak Akhatova, in CoolLIFE-Wiki, Other Materials - Beyond the Tool and the Hub.

Authors And Reviewers

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This page was written by Ardak Akhatova e-think.

This page was reviewed by Giulia Conforto e-think.

License

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Copyright © 2024-2025: Ardak Akhatova

Creative Commons Attribution 4.0 International License

This work is licensed under a Creative Commons CC BY 4.0 International License.

SPDX-License-Identifier: CC-BY-4.0

License-Text: https://spdx.org/licenses/CC-BY-4.0.html

Acknowledgement

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We would like to convey our deepest appreciation to the LIFE Programme CoolLIFE Project (Grant Agreement number 101075405), which co-funded the present investigation.

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