A Pioneering, Near-Zero-Carbon and All-Climate-Adaptive Air Conditioning System Using Atmospheric Latent Heat and Natural Light Energy

Air conditioning (AC) is one of the major energy systems applied globally with a market size of around £80 billion per annum. Current AC technologies require large amounts of electrical or thermal energy, accounting for 20% global electricity
consumption and resulting in 1,100 mega-tons of carbon emission.
The project aims to establish a scientific foundation for a pioneering, near-zero-carbon and all-climate-adaptive AC system. Compared to existing AC technologies (i.e. mechanical vapour compression, absorption, and adsorption types), the new AC system leads to over 80%-90% energy bills saving, and near-zero carbon emission. Unlike existing evaporative cooling AC systems which only suit arid climates, the new AC will be all-climate-adaptive.
Novelties of the research lie in: (1) The best performing sorption, diffusion, air-tight and light-absorptive materials will be identified and/or refined; (2) A unique sorption/desorption bed comprising an air-flow-interactive sorption layer and a light absorptive desorption layer will be developed; (3) A bespoke natural light harvesting configuration to deliver a controlled light radiation into the desorption layer surface; (4) The latest Fractal theory in the first attempt to a multi-medium/sized. porous block instead of the traditional single medium/sized porous block; (5) A unique multiple-scale light simulation model,
which integrate a non-sequential ray tracing method for simulating the macro-scale light and a finite-difference time-domain
method for simulating the light-moisture interaction on the porous desorption surface; (6) A novel 'life-cycle-cooling-cost'
oriented optimisation method.
The project research programme includes: (1) Screening, refinement, characterisation and selection of the sorption/desorption materials, and determination of the composition/combination methods of the selected materials; (2) Establishment of the theoretical foundation for the light collection/transmission/distribution and light-moisture interaction and conduction of associated computer simulation modelling; (3) Establishment of the theoretical foundation and computer models for moisture adsorption, permeation, diffusion and vaporisation within the porous 'moisture-breathing' bed, and optimisation of the structure of the 'moisture-breathing' bed; (4) Optimisation of the integrated operation between the light-driven 'moisture-breathing' bed and dew point air cooler using the 'life-cycle-cooling-cost' oriented method; and investigation of the AC's building integration approach; and (5) Construction/ testing of the AC prototype (including microbial hazard control) and validation/refinement of the integrated AC computer model.

Development of Moisture permeating porous foam and membrane type structures have been developed and characterised. Desorption layer formation is in progress.

In parallel atomistic molecular dynamics simulations in progress to corroborate our experimental observations and provide a screening method for determining future materials for testing based on water surface contact angle and pore diffusion predictions. This work will facilitate the design of more sustainable, adsorption-driven air-conditioning units.