The use of the technology described in this factsheet in building applications may lead to the following co-benefits [12,21,22]: 

• Enhance stability of the urban infrastructure: when connected to district heating /cooling networks 

• Boost local business (km 0) 

• Business and technological innovation 

• Job creation 

• Energy security 

• Reduced natural resource depletion 

• Reduced frequency and chances of disruption of energy provision 

• Reduced energy poverty 

• Increase access to clean, affordable, and secure energy 

• Social capacity building 

• Enhanced citizen participation and connectivity 

• Raised awareness and behavioural change 

• Improved access to job opportunities 

• Promotion of sustainable entrepreneurship 

• Promote the materials cycle 

• Improved air quality 

• Reduced health impacts from extreme heat or cold weather 

• Reduced ecological footprint 

• Air-to-air heat exchange 
• Direct ducting hot air 
• Heat captured during phase change 
• Passive building design strategies 
• Natural ventilation 
• Earth-air heat exchange technologies (EAHX) 
• Ambient energy 
• Improvement of energy efficiency by active and passive solutions in buildings 
• Guarantee to energy saving/production in buildings 

• Climate and geography:  

• Thermal energy storage for passive systems has a different response to each climate. 

• Heritage aspects may hinder the integration of TES technologies/systems. 

• Urban form and layout:  

• The urban form will strongly influence the performance of a building relying on any passive solutions (not only thermal insulation, but also shading, thermal capacity, etc.). 

• Technical aspects/infrastructure: 

• The integration of TES with district heating/cooling networks depends on the availability of such networks. 

• Policy and regulatory/legal framework:  

• Mostly related to the EU Energy Performance of Buildings Directive 2010/31/EU and the Energy Efficiency Directive 2012/27/EU, and their national transposition. 

• Funding and financing:  

• Incentives and subsidies can help in the implementation of this technology. 

• Economic and social context:  

• Understanding that the upfront investment is later recovered in the form of lower energy bills should be highlighted to final users; citizen awareness is important and needed. 

• Policy governance and implementation modalities:  

• Mobilisation of collective knowledge and skills, citizen-engagement and co-creation, stakeholder consultation, and public-private partnerships. 

Technologies that are within the building structure (i.e., PCMs integrate in building materials) can only be implemented in new buildings. 

On the other hand, technologies that are implemented in ceilings or floors are mostly appropriate for building refurbishment. 

Literature 

[1] Cabeza LF, Martorell I, Miró L, Fernández AI, Barreneche C. Introduction to thermal energy storage systems. Adv. Therm. Energy Storage Syst., Elsevier; 2021, p. 1–33. https://doi.org/10.1016/B978-0-12-819885-8.00001-2. 

[2] Arce P, Medrano M, Gil A, Oró E, Cabeza LF. Overview of thermal energy storage (TES) potential energy savings and climate change mitigation in Spain and Europe. Appl Energy 2011;88:2764–74. https://doi.org/10.1016/j.apenergy.2011.01.067. 

[3] Nair AM, Wilson C, Huang MJ, Griffiths P, Hewitt N. Phase change materials in building integrated space heating and domestic hot water applications: A review. J Energy Storage 2022;54:105227. https://doi.org/10.1016/j.est.2022.105227. 

[4] Takudzwa Muzhanje A, Hassan MA, Hassan H. Phase change material based thermal energy storage applications for air conditioning: Review. Appl Therm Eng 2022;214:118832. https://doi.org/10.1016/j.applthermaleng.2022.118832. 

[5] Li D, Zhuang B, Chen Y, Li B, Landry V, Kaboorani A, et al. Incorporation technology of bio-based phase change materials for building envelope: A review. Energy Build 2022;260:111920. https://doi.org/10.1016/j.enbuild.2022.111920. 

[6] Scuiller E, Bennici S, Dutournié P, Principaud F. Towards industrial-scale adsorptive heat storage systems: From state-of-the-art selected examples to preliminary conception guidelines. J Energy Storage 2022;53:105103. https://doi.org/10.1016/j.est.2022.105103. 

[7] Barbi S, Barbieri F, Marinelli S, Rimini B, Merchiori S, Bottarelli M, et al. Phase Change Material Evolution in Thermal Energy Storage Systems for the Building Sector, with a Focus on Ground-Coupled Heat Pumps. Polymers (Basel) 2022;14:620. https://doi.org/10.3390/polym14030620. 

[8] Mahon H, O’Connor D, Friedrich D, Hughes B. A review of thermal energy storage technologies for seasonal loops. Energy 2022;239:122207. https://doi.org/10.1016/j.energy.2021.122207. 

[9] Navarro L, de Gracia A, Niall D, Castell A, Browne M, McCormack SJ, et al. Thermal energy storage in building integrated thermal systems: A review. Part 2. Integration as passive system. Renew Energy 2016;85:1334–56. https://doi.org/10.1016/j.renene.2015.06.064. 

[10] Navarro L, de Gracia A, Colclough S, Browne M, McCormack SJ, Griffiths P, et al. Thermal energy storage in building integrated thermal systems: A review. Part 1. active storage systems. Renew Energy 2016;88:526–47. https://doi.org/10.1016/j.renene.2015.11.040. 

[11] de Gracia A, Cabeza LF. Phase change materials and thermal energy storage for buildings. Energy Build 2015;103:414–9. https://doi.org/10.1016/j.enbuild.2015.06.007. 

[12] Alizadeh M, Sadrameli SM. Development of free cooling based ventilation technology for buildings: Thermal energy storage (TES) unit, performance enhancement techniques and design considerations – A review. Renew Sustain Energy Rev 2016;58:619–45. https://doi.org/10.1016/j.rser.2015.12.168. 

[13] Kasaeian A, bahrami L, Pourfayaz F, Khodabandeh E, Yan WM. Experimental studies on the applications of PCMs and nano-PCMs in buildings: A critical review. Energy Build 2017;154:96–112. https://doi.org/10.1016/j.enbuild.2017.08.037. 

[14] Moreno P, Solé C, Castell A, Cabeza LF. The use of phase change materials in domestic heat pump and air-conditioning systems for short term storage: A review. Renew Sustain Energy Rev 2014;39:1–13. https://doi.org/10.1016/j.rser.2014.07.062. 

[15] Navarro L, De Gracia A, Castell A, Álvarez S, Cabeza LF. PCM incorporation in a concrete core slab as a thermal storage and supply system: Proof of concept. Energy Build 2015;103:70–82. https://doi.org/10.1016/j.enbuild.2015.06.028. 

[16] Iten M, Liu S, Shukla A. A review on the air-PCM-TES application for free cooling and heating in the buildings. Renew Sustain Energy Rev 2016;61:175–86. https://doi.org/10.1016/j.rser.2016.03.007. 

[17] Vakiloroaya V, Samali B, Fakhar A, Pishghadam K. A review of different strategies for HVAC energy saving. Energy Convers Manag 2014;77:738–54. https://doi.org/10.1016/j.enconman.2013.10.023. 

[18] Mahmoud M, Ramadan M, Naher S, Pullen K, Baroutaji A, Olabi A-G. Recent advances in district energy systems: A review. Therm Sci Eng Prog 2020;20:100678. https://doi.org/10.1016/j.tsep.2020.100678. 

[19] Gracia A De, Navarro L, Castell A, Ruiz-pardo Á, Álvarez S, Cabeza LF. Thermal analysis of a ventilated facade with PCM for cooling applications. Energy Build 2013;65:508–15. https://doi.org/10.1016/j.enbuild.2013.06.032. 

[20] Navarro L, De Gracia A, Castell A, Cabeza LF. Experimental evaluation of a concrete core slab with phase change materials for cooling purposes. Energy Build 2016;116:411–9. https://doi.org/10.1016/j.enbuild.2016.01.026. 

[21] Khadiran T, Hussein MZ, Zainal Z, Rusli R. Advanced energy storage materials for building applications and their thermal performance characterization: A review. Renew Sustain Energy Rev 2016;57:916–28. https://doi.org/10.1016/j.rser.2015.12.081. 

[22] Cabeza LF. Advances in thermal energy storage systems: methods and applications. Adv. Therm. Energy Storage Syst., Elsevier; 2021, p. 37–54. https://doi.org/10.1016/B978-0-12-819885-8.00002-4. 

[23] Ding W, Shi Y, Braun M, Kessel F, Frieß M, Bonk A, et al. Compatibility of 3d-printed oxide ceramics with molten chloride salts for high-temperature thermal energy storage in next-generation csp plants. Energies 2021;14. https://doi.org/10.3390/en14092599. 

Websites 

https://iea-es.org/ 

https://www.eera-set.eu/ 

https://ease-storage.eu

• Energy consumption 

• The inclusion of PCM in free-cooling systems can reduce up to 50% the fans electricity consumption [12,16] 

• Energy savings 

• Heat recovery systems can have energy savings between 8% in humid climates and 60% when linked with district heating systems [17,18] 

• TABS systems with PCM can achieve 19-26% energy savings if used in active façades [19] and 30-50% energy savings if used in concrete slabs [20] 

• PCM-based variable air volume air conditioning can achieve average energy savings between 28% and 47% [13] 

• Cost 

• A radiant floor with PCM can represent 18% cost reduction compared to a conventional radiant floor (when working with a heat pump system) [14] 

• Free-cooling systems including PCM can reduce the cost of a conventional ventilation system by 50%-90% [12] 

Projects 

LOWUP (H2020-funded project GA 723930): Within the LowUP project three different heating and cooling systems will be developed and demonstrated: HEAT-LowUP (low exergy heating system directly fed by solar and sewage water recovered heat), COOL-LowUP (low exergy cooling systems directly fed by renewable and free energy sources) and HP-LowUP (waste heat recovery and upgrading via heat pump). The first two systems are focused on the rational and efficient use of low valued energy sources for direct implementation in low-exergy heating & cooling systems for buildings and the third one is focused on the exploitation of low temperature residual energy, wasted with industrial processes, by upgrading them to generate useful heat to be re-introduced in the process. 

TubeICE (H2020 -funded project GA 778143): TubeICE project deals with the design, industrialization and commercialization of an innovative Phase Change Material (PCM) tubular shaped PTES unit, able to store energy within the range 22-27°C. 

WEDISTRICT (H2020-funded project GA 857801): The project demonstrates an integrated district heat and cooling (DHC) network combining renewable energy sources, thermal storage and waste heat recovery at low temperatures. Innovative concepts include use of molten salts for thermal storage, interaction with other energy networks, and end-user involvement through ICT solutions. 

StoRIES (H2020-funded project GA 101036910): Promoting a European ecosystem of industry and research organisations to develop innovative concepts and competitive and less costly energy storage technologies. By providing access to first-rate research infrastructures and services, the project will speed up the advancement of knowledge and technology in the field of energy storage. One of its technological goals is to optimise hybrid energy systems.