I. Knight1*, M. Rhodes1, F. Agyenim1 and E. Ampatzi1

1 Welsh School of Architecture, Cardiff University.
Corresponding Author, knight@,cf. ac. uk

Abstract

This paper provides conclusions from a WERC-funded project undertaken to assess the potential for Solar Thermal Heating and Cooling Systems to reduce the carbon emissions from domestic properties in Wales, UK. The project is based on 4 main elements:

• the physical testing of a novel solar thermally driven air-conditioning system in the Welsh climate to ascertain the real-world and laboratory performances of the system as a whole and its principal components

• the characterisation of the Welsh Housing stock into 13 major construction types

• the thermal modelling of these 13 types to obtain their heating, cooling and DHW demands, and hence their ‘traditional’ carbon emissions and the ‘solar thermal’ carbon emissions

• the aesthetic and design issues to do with integrating such systems into domestic properties, and their potential effect on the overall system efficiency

This paper synthesises some of the findings from these elements to provide a first answer to the question about the potential contribution that Solar Thermal technologies could make to reducing the carbon emissions associated with heating, cooling and DHW use, from both new and existing housing in Wales. This paper presents these findings for each of the housing types individually, as well as for the domestic sector in Wales as a whole.

This information is of importance in establishing whether Solar Thermal should be part of the country’s future energy mix, and potentially how much it could contribute. The work is especially timely within Wales’ stated ambition for all new buildings to be built to zero carbon standards by 2011.

The main conclusion from this work is that the use of Solar Thermal for heating, cooling and DHW for domestic housing in Wales leads to predicted reductions between 10 — 25% in the total carbon emissions, regardless of the type or age of dwelling.

Keywords: Solar Thermal Cooling, Solar Thermal Heating, Carbon Emissions Savings, Existing Buildings, Solar Thermal DHW, Wales

1. Introduction

This paper presents the main findings from a physical and thermal modelling study of the potential for Solar Thermal Air Conditioning Systems (STACS) to reduce the carbon emissions from the domestic housing sector in Wales, United Kingdom. As an autonomous region of the United Kingdom, Wales is one of only 3 countries in the World which have a commitment to sustainability written into their constitution. It is now actively exploring how it might reduce its Carbon emissions as part of this remit. A Renewable Energy Route Map for Wales was published by the Welsh Assembly Government in 2008 [1] exploring how Renewable Energy systems might contribute towards this goal across all sectors of society.

Previous conference papers [2 — 4] have introduced the first findings from the project, looking at the operation of STACS systems and the Welsh Housing stock. This paper, along with other papers presented at the EUROSUN 2008 conference [5 — 7], complete the findings from this project to date.

This paper is in 3 sections:

• A short summary of the Welsh Housing stock showing the % of each type of house in Wales.

• A review of the modelling findings for the heating, cooling and DHW demands for each house type, with and without Thermal Energy Storage.

• A first assessment, based on the above sections, of the potential contribution that STACS might make to the annual heating, cooling and DHW demands in each type of housing, and hence the Carbon Emission reductions that might be achieved in the Welsh Housing sector as a whole.