his project aims to develop, optimize, and manufacture novel polymer micro-hollow fibre heat exchangers (PHFHE) for various applications . This light weight PHFHE can reduce the weight up to 50% compared with traditional metal heat exchanger, leading to at least 50% cost reduction. The small diameters of the fibres (micrometers) have thin walls and large surface area so heat transfer intensity is significantly increased. PHFHE can be applied in the following sectors: 1) Buildings: holllow membrane fibres for liquid desiccant cooling and non-porous capillaries for air heat recuperation, air heaters and fan-coils; 2) Automotive: car radiators with same thermal power as traditional radiators but 50% lighter; 3) Electronics:heat transfer units for cooling compact electronic devices; 4) Water desalination:air humidification by pervaporation through hollow fibre membranes; 5) Energy Storage: non-porous hollow fibres for encapsulating PCMs can enhance heat transfer for passive cooling and energy storage applications. The implementation of such micro-fibre technology will offer cost effective and recycleable materials significant reduction in energy consumption and carbon emission.