Clive Edwards, Facilities and Maintenance Manager at The Building Centre, was behind the decision to install low carbon technology that would provide the hot water requirements for the entire building.
“We wanted to incorporate more LZC technologies into The Building Centre, not only to reduce the building’s carbon emissions but also because we want to encourage more building services engineers to investigate the different low carbon technologies available and I believe it is best to lead by example. We already have some renewable technologies installed within The Building Centre, such as heat pumps for the air conditioning system. However, much of the energy we consume is used in the production of hot water via electricity and this was the area I wanted to concentrate on next. After talking to Baxi Commercial Division, they suggested installing solar thermal, as this technology can significantly reduce energy usage and running costs.”
The previous hot water setup within The Building Centre consisted of two separate hot water systems, one operating on the third floor and the other serving the first and second floors. In total, these comprised two electric boilers and three cylinders. The new system, consisting of just one hot water storage cylinder integrated with the SOLARflo solar thermal package, was run alongside the existing hot water system until the solar thermal system itself was commissioned and installed. Consequently, everything was in position for the changeover, which took place over just one weekend. The old system could then be removed once the new one was up and running, thereby minimising downtime.
After careful assessment, it transpired that the layout and design of the Building Centre was ideal for solar thermal installation. The building has a large, south-facing roof with a natural 30-40° slant, which is the perfect angle for solar thermal collectors to optimise solar gain. In addition, the kitchen and adjoining workroom where the cylinder was installed were being refurbished, so the installation of the SOLARflo system was scheduled to fit in around the work that was already being carried out. This meant disruption was kept to an absolute minimum. The positioning of the new cylinder adjacent to the kitchen, which utilises the majority of the hot water, has also resulted in minimal standing heat loss and even greater efficiency.
Evacuated tubes were selected over glazed flat plate collectors mainly for ease of installation, as they could be transported to the roof in the lift, which would not have accommodated the flat plate collectors. This avoided the need for cranes or additional equipment. Evacuated tubes also require a lower surface area of collector array per litre of storage, so only 4m² of collectors were required, as opposed to 6m² of flat plate collectors.
“For me, the benefits of this system also extend to ease of maintenance,” said Clive. “By routing the pipework differently, all three floors are now served by the one system, with just the 300 litre electric cylinder providing storage and backup for the entire building. Utilising free energy also means I have more time and funds to spend on other low carbon projects in the future!”
Forthcoming legislation will require carbon reduction initiatives to be monitored, and Clive will be keeping a close record of the amount of electricity used by the new hot water system compared to the previous one. This information will serve to demonstrate how technologies like solar thermal can play an important role in reducing energy consumption in buildings.