Abstract
There are two main drivers for the consideration of ground source energy systems in the built environment in the UK today. Firstly, to reduce the operational costs of the provision of space heating and cooling and, secondly, to reduce the carbon dioxide emissions of the building. Building occupiers and owners are becoming increasingly concerned at rising energy prices and are seeking alternatives to conventional systems to reduce the running costs of buildings. Building designers, due to European and national legislation, are also required to reduce the operational CO<inf>2</inf> emissions from new and existing buildings. The capital costs for closed loop ground source heat pump systems are often found to be unattractive versus conventional approaches and low carbon alternatives. This paper will consider the optimisation of maximising the operational benefits whilst minimising the capital installation costs of closed loop ground source heating and cooling systems. Bivalent (dual fuel) heating and cooling systems offer a way to reduce the installation costs but also still provide considerable economic and environmental savings. A study example is presented for a newly proposed Academy (school) in the UK. The results of the study show a >40% reduction in the capital cost versus a peak sized GSHP systems whilst still providing >70% of the respective economic savings and CO<inf>2</inf> reduction.