The University of Greenwich extends across three campuses in SE London and Kent.  Following the completion of several successful projects for the University, we were engaged from RIBA Stage 1 to replace the ‘end of life’ gas heating network with the latest heat pump technology at its Avery Hill Campus. As the university has a Net Zero carbon goal by 2030 the scheme plays a major part towards reaching this ambitious target by decarbonising the Avery Hill facilities by 60%.

The existing gas fired district heating boiler plant had a capacity of 1.2MW and served five buildings, four of which are over 100 years old.  The boiler plant has been replaced by new air source heat pumps and equipment located within a main energy centre and satellite plant rooms via 1.2 kilometres of below ground pre-insulated welded steel pipework.  To adhere to the strict noise restrictions specified by the planning conditions, the air source heat pumps were fitted with bespoke acoustic enclosures.

The existing LTHW design temperatures of 78◦C flow is considerably higher than heat pumps typically deliver so each building now has its own satellite plant room with water-to-water heat pumps, which takes the LTHW water up to 78◦C. This design temperature was necessary as building fabric upgrades could not be carried out due to the age and heritage of existing buildings.

The changeover from the existing gas fired heating systems to the new systems was undertaken during the middle of winter, therefore the existing heating to the buildings needed to be maintained throughout the installation via a central temporary boiler, with each building then having to be transferred over to the new system following a stringently controlled changeover process. To complement the sustainability of the scheme, the system utilises demineralised water which optimises the efficiency of the heating network. This is controlled via an intelligent building management system which closely monitors energy usage and efficiency via an automatic meter reading (AMR) system.

The scheme also involved substantial adaptions to the existing LV distribution network and the installation of a new 1000kva transformer.

Role:

Mechanical and Electrical D&B Contractor

Main Contractor:

Mulalley

M & E Consultant:

Dench / SDA

Value:

£3.1M

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