Session 15 Paper 3, University College London, 16-17 April 2015
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The Department of Energy and Climate Change has recently announced a proposed doubling of GSHP Renewable Heat Incentive tariffs on smaller installations and tripling them on larger installations to support the growth of the GSHP market financially. It reflects the perceived importance of this technology to the United Kingdom. Ensuring long term performance is one of the key factors to achieve an economical and sustainable array design solution for this emerging technology.
Experience suggests the majority of plants installed in buildings are likely to be replaced in every 20 to 25 years in order to remain competitive. However, it is widely assumed that the ground arrays will have a relatively long life span for at least 50 years or even more. Nevertheless, the impact of future climate or the progressively tightening building regulation on insulation standards are not usually being considered in the array design process. This might lead to a significant reduction on the long term heat pump performance and minimising the carbon saving potential would have been received from this technology.
This paper is intended to investigate the influence of the climate and building insulation standards on the long term GSHP performance for a school building. A numerical analysis is carried out to simulate the long term performance of GSHP over 50 years. Future weather data will be adopted in order to simulate the future heating and cooling demands of the selected building under two different building insulation standards. The findings from this work suggest that impact of the future climate should always be considered in the design stage in order to optimise the thermal load ‘self balancing’ potential especially in a heating dominated building. The impact of improving the insulation standard is obvious when compared to the base case that only considering the current climate but less obvious when compared to the impact caused by the future climate alone. It is suggested that detailed numerical analysis is required to provide information that allows engineers to make the right design on the array length and heat pump capacity that could optimise the performance over the whole life perspective.