Council Offices, UK Local Authority

Heat recovery helps cut costs at ‘smarter’ council offices.

It is a two storey office building with a total floor area of 1,400m². The recently refurbished building is home to the council’s 187m² central server room, which powers the council’s IT network. About 130 council employees in various departments occupy the rest of the building.

After announcing plans seven years ago to rationalise its offices from 11 sites to just three, the council has been investing in improvements to this and the two other buildings, upgrading them to meet modern standards and accommodate relocated staff.

Like most councils, it had limited financial resources and challenging energy savings targets. Therefore, it had to develop a very robust business case in order to secure funding for retrofitting energy saving equipment in several council buildings.

Heat recovery helps cut costs at ‘smarter’ council offices.

SSE Enterprise was awarded the contract in December 2016, and commenced the design of measures for an initial phase of 14 council buildings. This was one of the biggest and most complex buildings in that phase due to its size and critical services.

By opting for Daikin’s three-pipe heat recovery system which can simultaneously heat and cool, SSE is able to utilise waste energy from the server room, and recycle it into other areas of the building – creating a truly smart building.

The heat recovery system, installed by SSE’s specialist sub-contractors, Huddersfield-based Daikin D1 Partner Crowther and Shaw, includes two condensing units, with a combined output of 28hp, located in a parking area. Indoors there are Roundflow cassettes, concealed ceiling units and a wall-mounted fan coil unit. The indoor units are individually controlled, giving each zone the ability to adjust temperatures slightly, if needed.

Kostas Papadopoulos, Head of Smart Cities Solutions Development for SSE Enterprise, says:

“We are extremely pleased with the initial energy savings achieved through the Re:fit project. Our technical team worked tirelessly to ensure the council would achieve maximum energy savings, contributing to the council’s overall carbon reduction target.”

To calculate the savings from the energy conservation measure (ECM) proposed, SSE used Integrated Environmental Systems (IES) software with the Ergon module to produce a simulation with 99.3% accuracy, based on real data. The analysis showed the existing cooling units had a seasonal energy efficiency rating (SEER) of 1.95, while the boilers’ seasonal efficiency was 60%.

SSE worked with Daikin’s bespoke IES plug-in to model how simultaneous heating and cooling would operate and predict the SEER in both modes. This simulation showed that the system could achieve a SEER of 3.37. On this basis SSE’s EPC guaranteed the council would save £4,228 a year and reduce CO₂ emissions by 29.4 tonnes.

In practice, however, results were even more impressive. Checks after six months showed operating cost savings were already up to £5,842.