The challenge

300 offices in a large campus building at the University were chosen to be retrofitted with Lightwave modules in an attempt to reduce heating costs. The building was controlled by an inflexible BMS; it was not possible to heat less than 200 rooms. If only one was occupied, over half of the building would have to be heated. Rooms were found to be constantly heated despite being unoccupied left with open windows.

The solution

Radiator valves and sensors

Lightwave Radiator Valves were hand fitted to every radiator without special tools. The valves could be controlled via an app by occupants and maintenance staff remotely.

The aim was to be able to control any room without affecting others, and implement flexible, automatic schedules from anywhere. In every office, movement sensors that automatically turned down the radiator if the room was left empty for an extended period were installed. Window triggers also turned down the temperature if windows were left open. Administrators could receive alerts via the Web App or email if windows were open or rooms left empty for long periods; of abnormal temperatures; and of maintenance issues such as low batteries.

Official findings

A significant saving

From the previous 4 years of data, the average annual carbon emissions associated with heating the building was 357 tonnes and the cost of heating was £44,563. From the results gained after analysing the performance of the LightwaveRF system, it was calculated that an average energy saving of 20% across the building could be expected. This equates to an annual saving of £8,900 (71 tonnes of Carbon).

A more detailed thermal modelling analysis predicted that savings of between 42% and 46% could be achieved in rooms where windows were frequently left open (as the system would automatically switch off the heating).

Further benefits

User engagement

Greater user control and improved user perception can decrease tendency to utilise expensive electric heaters.

Improved optimisation

The study represents an early adoption of the technology. With ongoing improvements, refinements and optimisation, Lightwave firmly believes that even better savings can now be achieved and results are eagerly awaited.

Thermal data

One of the other benefits of the system was found to be that the detailed heating data provided insights into room energy efficiency performance. Offices that were under or over heated, badly insulated rooms and those with defective windows could be identified and investigated.