Research Repository

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Effect of design parameters on thermal performance of integrated phase change material blind system for double skin façade buildings (2019)
Journal Article
Li, Y., Darkwa, J., Kokogiannakis, G., & Su, W. (2019). Effect of design parameters on thermal performance of integrated phase change material blind system for double skin façade buildings. International Journal of Low-Carbon Technologies, doi:10.1093/ijlct/ctz010

Double skin facades (DSFs) have overheating problems in warm seasons which may increase the cooling loads in buildings. A previous study has developed an integrated phase change material (PCM) blind system and proved its capacity of mitigating the ov... Read More

The micro/nano-PCMs for thermal energy storage systems: A state of art review (2019)
Journal Article
Arshad, A., Jabbal, M., Yan, Y., & Darkwa, J. (in press). The micro/nano-PCMs for thermal energy storage systems: A state of art review. International Journal of Energy Research,

With advancement in technology, the nanotechnology, various thermal energy storage (TES) materials have been invented and modified with promising thermal transport properties. The solid–liquid phase change materials (PCMs) have been extensively used... Read More

Experimental comparison of green facades with outdoor test cells during a hot humid season (2019)
Journal Article
Kokogiannakis, G., Darkwa, J., Badeka, S., & Li, Y. (2019). Experimental comparison of green facades with outdoor test cells during a hot humid season. Energy and Buildings, 185, 196-209. doi:10.1016/j.enbuild.2018.12.038

We used outdoor test cells during a hot humid period to analyse the surface temperatures behind the following four types of green walls: a felt layer wall; a planter boxes wall; a direct climbing plants wall, and; an indirect climbing plants wall. We... Read More

Experimental investigations into the adsorption enhancement in packed beds using Z-Annular flow configuration (2018)
Journal Article
Yeboah, S., & Darkwa, J. (2019). Experimental investigations into the adsorption enhancement in packed beds using Z-Annular flow configuration. International Journal of Thermal Sciences, 136, 121-134. doi:10.1016/j.ijthermalsci.2018.10.027

Annular packed bed structures have the potential to overcome limitations of conventional fully packed bed types by offering radial distribution of airflow within them to enhance fluid-solid contact during adsorption and also to minimize pressure drop... Read More

Thermal performance of a novel helically coiled oscillating heat pipe (HCOHP) for isothermal adsorption: an experimental study (2018)
Journal Article
Yeboah, S., & Darkwa, J. (2018). Thermal performance of a novel helically coiled oscillating heat pipe (HCOHP) for isothermal adsorption: an experimental study. International Journal of Thermal Sciences, 128, doi:10.1016/j.ijthermalsci.2018.02.014. ISSN 1290-0729

Helically Coiled Oscillating Heat Pipes (HCOHPs) have been designed and tested under laboratory conditions to investigate their potential to achieve isothermal adsorption when integrated with a cylindrical solid desiccant packed bed system. The HCOHP... Read More

Preparation of microencapsulated phase change materials (MEPCM) for thermal energy storage (2017)
Journal Article
Su, W., Darkwa, J., Kokogiannakis, G., Zhou, T., & Li, Y. (in press). Preparation of microencapsulated phase change materials (MEPCM) for thermal energy storage. Energy Procedia, 121, doi:10.1016/j.egypro.2017.07.485. ISSN 1876-6102

Microencapsulated phase change materials (MEPCM) could be used for energy saving applications in buildings due to their relatively high energy storage capacities at constant temperature, which could passively reduce peak cooling loads in summer. In t... Read More

Heat transfer analysis of an integrated double skin façade and phase change material blind system (2017)
Journal Article
Li, Y., Darkwa, J., & Kokogiannakis, G. (2017). Heat transfer analysis of an integrated double skin façade and phase change material blind system. Building and Environment, 125, doi:10.1016/j.buildenv.2017.08.034. ISSN 0360-1323

In this study, the heat transfer in an integrated double skin facade (DSF) and phase change material (PCM) blind system has been theoretically analysed. Both heat transfer and airflow models with CFD methods have been developed for the integrated DSF... Read More

Multiphase change materials for energy storage application in buildings (2017)
Journal Article
Darkwa, J., & Su, W. (2017). Multiphase change materials for energy storage application in buildings. Journal of Thermophysics and Heat Transfer, 31(4), doi:10.2514/1.T5101. ISSN 0887-8722

Experimental study has been carried out towards the development of a multiphase change material (MCM) by combining two fabricated microencapsulated phase change materials (MEPCM-oct and MEPCM-eic) samples. The study also covered the characterization... Read More

Review of solid–liquid phase change materials and their encapsulation technologies (2017)
Journal Article
Su, W., Darkwa, J., & Kokogiannakis, G. (2017). Review of solid–liquid phase change materials and their encapsulation technologies. Renewable and Sustainable Energy Reviews, 48, doi:10.1016/j.rser.2015.04.044. ISSN 1364-0321

Various types of solid–liquid phase change materials (PCMs) have been reviewed for thermal energy storage applications. The review has shown that organic solid–liquid PCMs have much more advantages and capabilities than inorganic PCMs but do possess... Read More

Development of microencapsulated phase change material for solar thermal energy storage (2016)
Journal Article
Su, W., Darkwa, J., & Kokogiannakis, G. (2017). Development of microencapsulated phase change material for solar thermal energy storage. Applied Thermal Engineering, 112, doi:10.1016/j.applthermaleng.2016.11.009. ISSN 1359-4311

In this paper a novel microencapsulated phase change material (MF-3) has been developed and tested for solar assisted hot water storage systems. Even though the morphology of the sample was affected by the type of emulsifier used for fabrication it r... Read More

Development of a novel phase change material emulsion for cooling systems (2015)
Journal Article
Shao, J., Darkwa, J., & Kokogiannakis, G. (2016). Development of a novel phase change material emulsion for cooling systems. Renewable Energy, 87, doi:10.1016/j.renene.2015.10.050. ISSN 0960-1481

In this paper, a novel phase change material emulsion (PCE-10) consisting of an organic PCM (RT10) and water has been developed. Its thermophysical properties such as heat of fusion, viscosity and sub-cooling temperature have been established. The ch... Read More

Review of phase change emulsions (PCMEs) and their applications in HVAC systems (2015)
Journal Article
Shao, J., Darkwa, J., & Kokogiannakis, G. (2015). Review of phase change emulsions (PCMEs) and their applications in HVAC systems. Energy and Buildings, 94, doi:10.1016/j.enbuild.2015.03.003. ISSN 0378-7788

Phase change material emulsions (PCMEs) are multifunctional fluids consisting of phase change materials (PCMs) and carrier fluids. PCMEs could be potential candidates as heat transfer media in heating, ventilation and air conditioning (HVAC) systems.... Read More

Thermal evaluation of laminated composite phase change material gypsum board under dynamic conditions (2015)
Journal Article
Zhou, T., Darkwa, J., & Kokogiannakis, G. (2015). Thermal evaluation of laminated composite phase change material gypsum board under dynamic conditions. Renewable Energy, 78, doi:10.1016/j.renene.2015.01.025. ISSN 0960-1481

Thermal evaluation of non-deform laminated composite phase change material (PCM) gypsum board has been carried out. The theoretical studies covered the analysis of different thicknesses of PCM layers and their corresponding heat transfer rates during... Read More

Evaluation of thermal energy dynamics in a compacted high-conductivity phase-change material (2015)
Journal Article
Darkwa, J., Su, O., & Zhou, T. (2015). Evaluation of thermal energy dynamics in a compacted high-conductivity phase-change material. Journal of Thermophysics and Heat Transfer, 29(2), doi:10.2514/1.T3911. ISSN 0887-8722

This study evaluates the concept of developing a nondeform phase-change energy storage material possessing higher thermal conductivity and energy storage density through a pressure compaction process. The theoretical and experimental investigations h... Read More

A survey on development of energy service industry in Zhejiang China (2014)
Journal Article
Qu, Y., Wang, X. Y., & Darkwa, J. (in press). A survey on development of energy service industry in Zhejiang China. Applied Mechanics and Materials, 587-589, doi:10.4028/www.scientific.net/AMM.587-589.140

Energy service industry (ESI) has grown quickly recent year in China. A main and important role in ESI is Energy Service Company (ESCO) which engages in reducing energy consumption through retrofitting the existing facilities. This survey focuses on... Read More

Support for the integration of green roof constructions within Chinese building energy performance policies (2013)
Journal Article
Kokogiannakis, G., & Darkwa, J. (2014). Support for the integration of green roof constructions within Chinese building energy performance policies. Energy, 65, doi:10.1016/j.energy.2013.11.076. ISSN 0360-5442

Green roofs could act as a thermal buffer in buildings and offer potential energy savings. However, the energy benefits from green roofs are not usually properly recognised by traditional building energy regulations. Building energy regulations are t... Read More

Simulating the influence of microclimatic design on mitigating the urban heat island effect in the Hangzhou metropolitan area of China (2013)
Journal Article
Shen, T., Chow, D., & Darkwa, J. (2016). Simulating the influence of microclimatic design on mitigating the urban heat island effect in the Hangzhou metropolitan area of China. International Journal of Low-Carbon Technologies, 11(1), doi:10.1093/ijlct/ctt050. ISSN 1748-1317

There are many indications that Urban Heat Island (UHI) is a significant contributor to the increased emission of greenhouse gases due to the increase in energy consumption for cooling during summer. Hangzhou is currently the second hottest city in C... Read More

Performance of an integrated solar absorption cooling system in a sub-tropical region (2012)
Journal Article
Darkwa, J., & Fraser, S. (2012). Performance of an integrated solar absorption cooling system in a sub-tropical region. International Journal of Low-Carbon Technologies, 7(3), doi:10.1093/ijlct/cts024. ISSN 1748-1317

Evaluation of an integrated solar absorption cooling system located in a sub-tropical region has been carried out. Analysis of the results revealed an operational efficiency of 61% for the solar collectors at a mean differential temperature forumla o... Read More