Publication Summary
The air conditioning industry has, in recent years, come under sustained attack from a range of economic, environmental and regulatory pressures. Global environmental concerns, improving standards of ventilation and increasing concerns about indoor air quality have all contributed to a change in design thinking. Professional guidance is increasingly steering clients and consultants away from full air conditioning to natural ventilation and mixed -mo e solutions in new and refurbishment projects. Nevertheless inefficient lighting, increases in computing equipment and architectural fashion mean that overheating is the predominant design consideration for new offices in the UK. The situation is likely to worsen if glo bal warming scenarios are accurate. 1 Hence it is vitally important that the building industry seeks innovative methods of maintaining and improving the quality of the indoor environment, under potentially more demanding performance criteria, without increasing environmental impact. The occurrence of cooling power in phase with cooling load suggests a compelling argument in favour of consideration of air conditioning powered by the sun displacing peak load electricity in summer. Desiccant cooling is a potentially benign technology which can be used to condition the internal environment of buildings. Unlike conventional air conditioning systems which rely on electrical energy to drive the cooling cycle, desiccant cooling is one of a number of emerging heat driven cycles. By using gas -solar hybrid desiccant cooling and dehumidification technology it may be possible to offer a benign solution to cooling of buildings, in new and refurbishment situations, reduce dependence on harmful refrigerants and significant ly reduce greenhouse gas emissions which result from air conditioning demands. This paper is a development of an earlier study, and uses real meteorological data to evaluate the feasibility of using solar energy to drive the desiccant cooling cycle in a United Kingdom application. Through the use of parametric studies, the paper investigates the energy consumption and costs associated with solar desiccant cooling. A steady state desiccant model has been developed which initially investigated the solar con tribution to the cooling load for a range of ventilation rates and regeneration temperatures. A model was then developed to predict the heat available for desiccant regeneration for any given set of meteorological data, solar collector algorithm and orien tation. Early indications are that a significant amount of the cooling load can be provided from the solar energy (50%) with savings in running cost and reduction in CO2 emissions.
