Martin Mayfield

Bio: Martin Mayfield is an academic researcher from University of Sheffield. The author has contributed to research in topics: Energy consumption & Scale (ratio). The author has an hindex of 11, co-authored 46 publications receiving 446 citations.

What is a Smart Building

Abstract: Purpose – Within the building sector a lack of clarity in terminology does not help designers, clients or researchers. Non-domestic buildings have shown rapid increases in the use of advanced technology and control systems with varying drivers, many of which are labelled as intelligent. The term smart has been used interchangeably with intelligent without any clear distinction between the two. If the term Smart Buildings represented a separate, more advanced grouping, it would provide an opportunity to focus the future progress of non-domestic building development. The paper aims to discuss these issues. Design/methodology/approach – Drawing upon academic and industrial literature and experience, this paper reviews the scope of Intelligent Buildings and the current available definitions of Smart Buildings to form a clear definition of both smart and Intelligent Buildings. Findings – These definitions define the border between the intelligent and the (more advanced) Smart Building. The upper bound of the S...

Analysing the performance of low-cost air quality sensors, their drivers, relative benefits and calibration in cities—a case study in Sheffield

Abstract: Traditional real-time air quality monitoring instruments are expensive to install and maintain; therefore, such existing air quality monitoring networks are sparsely deployed and lack the measurement density to develop high-resolution spatiotemporal air pollutant maps. More recently, low-cost sensors have been used to collect high-resolution spatial and temporal air pollution data in real-time. In this paper, for the first time, Envirowatch E-MOTEs are employed for air quality monitoring as a case study in Sheffield. Ten E-MOTEs were deployed for a year (October 2016 to September 2017) monitoring several air pollutants (NO, NO2, CO) and meteorological parameters. Their performance was compared to each other and to a reference instrument installed nearby. E-MOTEs were able to successfully capture the temporal variability such as diurnal, weekly and annual cycles in air pollutant concentrations and demonstrated significant similarity with reference instruments. NO2 concentrations showed very strong positive correlation between various sensors. Mostly, correlation coefficients (r values) were greater than 0.92. CO from different sensors also had r values mostly greater than 0.92; however, NO showed r value less than 0.5. Furthermore, several multiple linear regression models (MLRM) and generalised additive models (GAM) were developed to calibrate the E-MOTE data and reproduce NO and NO2 concentrations measured by the reference instruments. GAMs demonstrated significantly better performance than linear models by capturing the non-linear association between the response and explanatory variables. The best GAM developed for reproducing NO2 concentrations returned values of 0.95, 3.91, 0.81, 0.005 and 0.61 for factor of two (FAC2), root mean square error (RMSE), coefficient of determination (R2), normalised mean biased (NMB) and coefficient of efficiency (COE), respectively. The low-cost sensors offer a more affordable alternative for providing real-time high-resolution spatiotemporal air quality and meteorological parameter data with acceptable performance.

Life cycle impact comparison of different concrete floor slabs considering uncertainty and sensitivity analysis

Abstract: The traditional construction industry is characterized as a labor-intensive, wasteful, and inefficient sector. Currently, prefabrication has become a common practice in residential development and has reduced energy consumption and waste generation compared to traditional on-site practices. This study investigates the differences in life cycle environmental impacts among three different floor systems (precast slab, composite slab (semi-precast slab) and cast-in-situ slab) based on two functional units (delivering the same carrying capacity and maintaining consistent floor depth) using both LCA midpoint and endpoint methods using the software tool SimaPro. This study sets a calculation boundary for the construction process: raw material production, slab production, transportation, construction activities on-site, demolition and recycling of buildings at the end-of-life stage. Moreover, uncertainty and sensitivity analysis are carried out to help decision-makers identify major environmental impact factors and develop eco-friendly plans to facilitate housing industrialization. The results indicate that (1) the environmental impact of precast slab outperforms those of cast-in-situ and composite floors regardless of different design functional units and evaluation methods. (2) While under different functional units, the environmental performance of composite and cast-in-situ floors varies considerably. (3) From the perspective of life cycle stages, the transportation sector and its supply chain make up a significant portion of the final environmental impact and are responsible for 45.2%, 50.1% and 53.6% of the total impact for the precast, composite and cast-in-situ slabs, respectively. Slab production of precast slab (it is raw material production of cast-in-situ and composite slabs) is the second largest contributor to the environmental impact.

Reducing carbon emissions by integrating urban water systems and renewable energy sources at a community scale

Abstract: This paper presents a novel take on the energy-water nexus; exploring the coupling of renewable generation sources with drinking water distribution and wastewater collection assets that can store and release energy in response to temporal changes in residential heat demand. The paper presents the development of a simulation tool that uniquely integrates energy storage in drinking water reservoirs, heat recovery from sewers with wind turbine(s), solar photovoltaic panel(s) and a non-renewable source. Simulations at the scale of a 1000 household community and hourly intervals were used to find the optimal energy generation mix that minimises the total annual carbon emissions (embedded and operational). Three different locations in the UK were studied. Results show that the integrated idealised system is able to satisfy the heat demand for up to 63% of the time across a year with no carbon emissions, and reduce the annual associated C O 2 by 60% when compared to all heat demand being satisfied by natural gas. This work shows that adopting such an interlinked system at a typical neighbourhood scale could help the UK meet its carbon emission obligations by substantially reducing the 18% of the UK's C O 2 emission (currently estimated to be) related to domestic heat use.

Ecological network analysis on intra-city metabolism of functional urban areas in England and Wales

Abstract: The UK has one of the world’s most urbanised societies where nearly 83% of the total population lives in cities. The continuing population growth could lead to increases in environmental pollutions and congestion within cities. The framework of urban metabolism uses an analogy between cities and ecosystems to study the metabolic processes within complex urban systems akin to natural biological systems. It remains as a challenge to fully understand the complicated distribution of resource flows within an urban network. In this paper, Ecological Network Analysis was applied to study the intra-city flows between economic sectors in 35 functional urban areas in order to investigate their respective metabolic relationships. The intra-city flows network of each area was also supplemented with the geographical distance between the workplace zones to study the impacts of spatial distribution on the density of resource flows. The metabolic systems were dominated by 64% of exploitative relationships with an average mutualism index of 0.93 and synergism index of 3.56 across all 35 areas. The consumption-control and production-dependency relationships revealed the hierarchical orders among the sectors resembling the pyramidal structure of an urban ecosystem. Network community classification emphasized the importance of inter-relationship within the organisation of each community class. The producer-type and consumer-type communities showed the tendencies of those sectors to cluster based on their respective hierarchical roles in the ecosystem. This work provides an insight into the wide range of intra-city ecological metabolic characteristics which can potentially expand to a multi-scale assessment of urban metabolism across the country.

[ACM Press the 2nd ACM Workshop - Zurich, Switzerland (2010.11.02-2010.11.02)] Proceedings of the 2nd ACM Workshop on Embedded Sensing Systems for Energy-Efficiency in Building - BuildSys \'10 - Occupancy-driven energy management for smart building automation

Abstract: Buildings are among the largest consumers of electricity in the US. A significant portion of this energy use in buildings can be attributed to HVAC systems used to maintain comfort for occupants. In most cases these building HVAC systems run on fixed schedules and do not employ any fine grained control based on detailed occupancy information. In this paper we present the design and implementation of a presence sensor platform that can be used for accurate occupancy detection at the level of individual offices. Our presence sensor is low-cost, wireless, and incrementally deployable within existing buildings. Using a pilot deployment of our system across ten offices over a two week period we identify significant opportunities for energy savings due to periods of vacancy. Our energy measurements show that our presence node has an estimated battery lifetime of over five years, while detecting occupancy accurately. Furthermore, using a building simulation framework and the occupancy information from our testbed, we show potential energy savings from 10% to 15% using our system.

Triumph of the City

Abstract: Edward Glaeser, Basingstoke and Oxford, Palgrave Macmillan, 2011, 338 pp., £25.00 (hbk), ISBN 9780230709386 This is a book that was waiting to be written—a popular book on the contemporary urban co...

Validation of calibrated energy models: Common errors

Abstract: Nowadays, there is growing interest in all the smart technologies that provide us with information and knowledge about the human environment. In the energy field, thanks to the amount of data received from smart meters and devices and the progress made in both energy software and computers, the quality of energy models is gradually improving and, hence, also the suitability of Energy Conservation Measures (ECMs). For this reason, the measurement of the accuracy of building energy models is an important task, because once the model is validated through a calibration procedure, it can be used, for example, to apply and study different strategies to reduce its energy consumption in maintaining human comfort. There are several agencies that have developed guidelines and methodologies to establish a measure of the accuracy of these models, and the most widely recognized are: ASHRAE Guideline 14-2014, the International Performance Measurement and Verification Protocol (IPMVP) and the Federal Energy Management Program (FEMP). This article intends to shed light on these validation measurements (uncertainty indices) by focusing on the typical mistakes made, as these errors could produce a false belief that the models used are calibrated.

Comprehensive analysis of the relationship between thermal comfort and building control research - A data-driven literature review

Abstract: Buildings are responsible for about 30–40% of global energy demand. At the same time, we humans spend almost our entire life, up to 80–90% of the time, inside of buildings. Reducing energy demand through optimal operation is the subject of building control research, while human satisfaction in buildings is studied in the thermal comfort community. Thus, balancing the two is necessary for a sustainable and comfortable building stock. We review both research fields and their relationship using a data-driven approach. Based on specific search terms, all relevant abstracts from the Web Of Science database are downloaded and analyzed using the text mining software VOSviewer. We visualize the scientific landscapes of historic and recent trends, and analyze the citation network to investigate the interaction between thermal comfort and building control research. We find that building control focuses predominantly on energy savings rather than incorporating results from thermal comfort, especially when it comes to occupant satisfaction. We identify potential research directions in terms of bridging the two fields.