Open University, Milton Keynes
The education sector is championing the uptake of heat pumps in the UK, providing an important showcase for the fast growth of the heat pump market.
The Open University in Milton Keynes is a 2000 sq metre sustainable new-build development that forms part of the Walton Hall campus.
Sustainability and carbon reduction were the core requirements of the customer.
The new building, which opened in early 2011, is targeting a BREEAM Outstanding rating.
It incorporates natural ventilation, night time cooling, solar chimneys, automatic lighting controls, a green roof, solar water heating and PV panels.
The solution
Thirteen boreholes were drilled to a depth of 100+ metres to install a ground loop system feeding four Robur gas absorption heat pumps, with ground source renewable energy (GAHP GS) with a capacity of 140 kW heat output, providing heating and domestic hot water as well.
The operation of Robur ground source gas absorption heat pumps is very simple and reliable: the thermal energy absorbed by the earth is enhanced by the refrigeration cycle.
The outcomes
- The four Robur ground source gas absorption heat pumps GAHP GS provide up to 40.9% utilisation of ground source renewable energy, exceeding peak efficiencies of 169% and 40.9% reductions in annual heating costs and in CO2 emissions compared to condensing boilers.
- Every year the Robur GAHPs installed at the Open University save 20.4 tons of CO2 emissions, equivalent to those absorbed by 2,856 trees or those produced by 8 green cars; every year 8.8 TOE are saved.
- Legislative benefits include cost savings relating to the Carbon Reduction Commitment Energy Efficiency Scheme and improved Building Energy Certificate ratings.
- Gas absorption heat pumps enables points for BREEAM assessment as a result of low emissions.
- Robur gas absorption heat pumps work very effectively to deliver reliable and affordable low carbon heat, contributing to the University’s carbon reduction strategy.