Gaia Research undertook research to determine whether desiccant-cooling technology using solar generated low temperature heat for regeneration, might be reliable and cost effective in the UK in the near future.
Desiccant cooling is a potentially clean technology, which can be used to condition the internal environment of buildings without the use of refrigerants. Unlike conventional air conditioning systems, which rely on electrical energy to drive the cooling cycle, desiccant cooling is an open, heat-driven cycle, which uses a desiccant wheel in tandem with heat recovery to achieve both cooling and dehumidification. The temperatures required for regeneration are low and Gaia wished to investigate if they were potentially compatible with solar generation and waste heat.
The research required monitoring of desiccant ventilation plant in the Midlands and in Scotland. The energy performance and control strategies of these two installed systems were analysed over a period of one year and the potential energy savings and reduction in greenhouse gas emissions assessed compared to alternatives. A desiccant-cooling model was developed, and validated using data gathered from the two study buildings. The model predicts the running costs of desiccant systems.
In addition an assessment was made of what could be achieved if solar energy was utilised to drive the cycle. This was integrated with solar data to provide information on gas and gas/solar hybrid options based on real meteorological data and the actual performance of the two case study systems.