The UK is facing a retrofit challenge due to its legacy of old homes which are poorly suited to modern expectations of indoor thermal comfort. The housing stock accounts for almost a third of total energy use and is responsible for significant CO2 emissions. There is global recognition that the current rate of greenhouse gas emissions is causing long term damage and that changes are required in all sectors in order to limit the impacts of our generation on the global climate. The energy service concept offers an alternative perspective on the energy system. It reframes our demand for energy as a desire for the service which it can provide, such as comfortable homes, illuminated spaces, warm meals and security.
This thesis is an investigation of how energy efficiency technologies and measures can deliver energy services with a lower energy input and uses building modelling software as a tool to do so. Four approaches to improving energy service efficiency are compared, and these are high efficiency conversion device, improved passive system, more accurate service control and a reduced service level. These energy efficiency measures are compared based on energy savings attainable and the efficacy of energy service delivery, using the example service of heating thermal comfort. In recognition of the large influence that household occupants have on energy consumption, household behaviours are included in the analysis. Household occupancy pattern is used to define the service demanded and thus energy efficiency measures are compared for a working family, working couple and daytime-present couple occupancy pattern. The suitability of measures for different households is addressed according to elements of motivation for energy efficiency improvement and technical skills of the occupants.
The results of this work show that improved passive system performed best in both energy savings and heating thermal comfort delivery for all occupancy patterns. However, combinations of lower cost measures of control and service level demonstrate an ability to deliver comparable energy savings for occupancy patterns of working couple and daytime-present couple. The findings of this thesis confirm the importance of improving the thermal performance of the housing stock, but also that increased adoption of heating controls and a readdressing of expectations of service level can deliver significant energy savings. The modelling of the delivery of thermal comfort requires an enhanced modelling approach, but offers the ability for energy efficiency recommendations to be made based on suitability for the household, which will lead to greater energy savings within the domestic sector.
