Thermal performance of thermoactive continuous flight auger piles

Foundation piles are being increasingly equipped with heat exchangers to efficiently harvest shallow geothermal energy. For buildings in urban areas, continuous flight auger (CFA) piles are common owing to their speed, cost-efficiency and low noise levels. To construct a thermoactive CFA pile usually requires separate central installation of the heat exchanger. However, the energy performance of this type of pile has not been investigated systematically, with most studies focused on rotary piles where the heat exchanger is attached to the reinforcing cage. In this work, insights are provided about the main influences on the energy efficiency of thermoactive CFA piles, with a focus on the implications of using CFA construction techniques rather than rotary boring. An innovative three-dimensional numerical model, able to capture the different aspects of transient heat transfer, is employed together with analytical methods to evaluate the transient and steady-state behaviour of energy piles in a number of design situations. Attention is given to understanding the role of possible pipe-to-pipe interaction, which cannot be systematically investigated with standard methods. Finally, practical guidelines on the optimal choice of design parameters to maximise the energy efficiency of CFA piles, without altering the geotechnical arrangements, are provided

Air conditioning and electricity expenditure: The role of climate in temperate countries

This paper investigates how households adopt and use air conditioning to adapt to climate change and increasingly high temperatures, which pose a threat to the health of vulnerable populations. The analysis examines conditions in eight temperate, industrialized countries (Australia, Canada, France, Japan, the Netherlands, Spain, Sweden, and Switzerland). The identification strategy exploits cross-country and cross-household variations by matching geocoded households with climate data. Our findings suggest that households respond to excess heat by purchasing and using air conditioners, leading to increased electricity consumption. Households on average spend 35%–42% more on electricity when they adopt air conditioning. Through an illustrative analysis, we show that climate change and the growing demand for air conditioning are likely to exacerbate energy poverty. The number of energy poor who spend a high share of income on electricity increases, and households in the lowest income quantile are the most negatively affected

Holistic narratives of the renovation experience: Using Q-methodology to improve understanding of domestic energy retrofits in the United Kingdom

The energy efficient retrofit of existing building stocks can help to address various social, economic and environmental objectives. As the most cost-effective and least disruptive retrofit options have regularly been implemented as a priority, initiatives that seek to encourage continued retrofit are likely to require thoughtful improvements in their design. Understanding the population of households that may be interested in retrofit as a heterogeneous rather than a homogenous group is a critical part of improving support for retrofit. In this research, we use Q-methodology to disaggregate the home owner-occupier population of the UK and create narratives that represent their experience of home renovations. We consider the experience of general home renovations as typically households do not see these as distinctive from energy efficient retrofit. The narratives present a holistic perspective by incorporating a comprehensive range of the influences on the renovation experience. The developed narratives – ‘Organised and seeking greater comfort’, ‘Settled and performing a functional upgrade’, ‘Growing and needing a family home’ and ‘A lot to do and no time like the present’ – provide the opportunity to better understand those making renovation decisions and subsequently develop more appropriate interventions to promote retrofit

Future-Proofed Energy Design for Dwellings: Case studies from England and Application to the Code for Sustainable Homes

This paper investigates ‘future-proofing’ as an unexplored yet all-important aspect in the design of low-energy dwellings. It refers particularly to adopting lifecycle thinking and accommodating risks and uncertainties in the selection of fabric energy efficiency measures and low or zero-carbon technologies. Based on a conceptual framework for future-proofed design, the paper first presents results from the analysis of two ‘best practice’ housing developments in England; i.e., North West Cambridge in Cambridge and West Carclaze and Baal in St. Austell, Cornwall. Second, it examines the ‘Energy and CO2 Emissions’ part of the Code for Sustainable Homes to reveal which design criteria and assessment methods can be practically integrated into this established building certification scheme so that it can become more dynamic and future-oriented