Improving predictions of operational energy performance through better estimates of small power consumption

This Engineering Doctorate aims to understand the factors that generate variability in small power consumption in commercial office buildings in order to generate more representative, building specific estimates of energy consumption. Current energy modelling practices in England are heavily focussed on simplified calculations for compliance with Building Regulations, which exclude numerous sources of energy use such as small power. When considered, estimates of small power consumption are often based on historic benchmarks, which fail to capture the significant variability of this end-use, as well as the dynamic nature of office environments. Six interrelated studies are presented in this thesis resulting in three contributions to existing theory and practice. The first contribution consists of new monitored data of energy consumption and power demand profiles for individual small power equipment in use in contemporary office buildings. These were used to inform a critical review of existing benchmarks widely used by designers in the UK. In addition, monthly and annual small power consumption data for different tenants occupying similar buildings demonstrated variations of up to 73%. The second contribution consists of a cross-disciplinary investigation into the factors influencing small power consumption. A study based on the Theory of Planned Behaviour demonstrated that perceived behavioural control may account for 17% of the variation in electricity use by different tenants. A subsequent monitoring study at the equipment level identified that user attitudes and actions may have a greater impact on variations in energy consumption than job requirements or computer specification alone. The third contribution consists of two predictive models for estimating small power demand and energy consumption in office buildings. Outputs from both models were validated and demonstrated a good correlation between predictions and monitored data. This research also led to the development and publication of industry guidance on how to stimate operational energy use at the design stage

Analysis of electricity consumption for lighting and small power in office buildings

There is significant evidence to suggest that buildings do not perform as well as expected, and this is commonly referred to as the "performance gap". Energy compliance calculations for Building Regulations in England and Wales do not include sources of energy consumption in buildings such as small power, catering, external lighting and vertical transportation (i.e. lifts and escalators). These so called "unregulated" loads are therefore rarely included in building energy models, and the lack of feedback regarding the in-use performance of buildings makes it harder for designers to quantify their impact on the overall energy consumption of a building. Aiming to address these issues, this paper provides an analysis of monitored electricity consumption in two multi-tenanted office buildings, with one tenant in common in both buildings. This paper focuses on tenant electricity consumption, including lighting and small power. Detailed analysis of the monitored data demonstrates significant variation between the electricity consumption of different tenants occupying the same building whilst performing similar activities. Elements such as lighting controls, hours of occupancy and management decisions are observed to have a significant impact on such variations. Further analysis of half-hourly energy consumption data is also provided, in addition to a detailed breakdown of small power energy consumption due to individual office equipment. Future work will build on this study and aim to develop evidence based benchmarks for energy consumption in office buildings. It will include a "tailoring" component allowing the benchmarks to be adjusted according to profiles of occupancy and management behaviour, as well as workstation density and the specification of energy consuming equipment. It is expected that such benchmarks will inform designers about the impact of each of these parameters on the measured energy consumption of buildings

Predicted vs. actual energy performance of non-domestic buildings: using post-occupancy evaluation data to reduce the performance gap

With the increasing demand for more energy efficient buildings, the construction industry is faced with the challenge to ensure that the energy performance predicted during the design stage is achieved once a building is in use. There is, however, significant evidence to suggest that buildings are not performing as well as expected and initiatives such as PROBE and CarbonBuzz aim to illustrate the extent of this so called ‘performance gap’. This paper discusses the underlying causes of discrepancies between energy modelling predictions and in-use performance of occupied buildings (after the twelve month liability period). Many of the causal factors relate to the use of unrealistic input parameters regarding occupancy behaviour and facilities management in building energy models. In turn, this is associated with the lack of feedback to designers once a building has been constructed and occupied. The paper aims to demonstrate how knowledge acquired from Post-Occupancy Evaluation (POE) can be used to produce more accurate energy performance models. A case study focused specifically on lighting, small power and catering equipment in a high density office building is analysed and presented. Results show that by combining monitoring data with predictive energy modelling, it was possible to increase the accuracy of the model to within 3% of actual electricity consumption values. Future work will seek to use detailed POE data to develop a set of evidence based benchmarks for energy consumption in office buildings. It is envisioned that these benchmarks will inform designers on the impact of occupancy and management on the actual energy consumption of buildings. Moreover, it should enable the use of more realistic input parameters in energy models, bringing the predicted figures closer to reality

Benchmarking small power energy consumption in UK office buildings: a review of data published in CIBSE guide F

CIBSE’s Guide F is a widely recognised guidance document on energy efficiency in buildings, which includes energy consumption benchmarks for small power equipment in offices. In its recently published 3rd edition, existing power demand benchmarks for office equipment were revised to better represent appliances found in contemporary office buildings. Other key sources of data such as typical operating hours for equipment, however, have been omitted. This paper compares the benchmarks published in both the 2nd and 3rd editions of Guide F against a set of measurements of small power loads in a real UK office building. Load profiles for the monitored equipment are also presented to supplement the information included in the new Guide F. Practical application: With the increasing demand for more realistic predictions of operational energy use in buildings, small power should not be disregarded since it typically accounts for more than 20% of total energy used in offices. Furthermore, small power loads can have a significant impact on the cooling loads of a building. This paper reviews existing benchmarks, focusing on the new update to CIBSE Guide F, comparing available benchmarks against newly gathered monitored data. Detailed load profiles for individual office equipment are also provided, which can be used by designers to inform better predictions of small power consumption in office buildings

Review of benchmarks for small power consumption in office buildings

There is significant evidence to suggest that buildings consume more energy than initially predicted during the design phase of building procurement. With increasing efforts to reduce the energy consumption associated with the operation of buildings, it is vital that these predictions be improved to represent the operation of buildings more realistically. One approach to bridge this gap would be to include energy consumption due to small power equipment in the energy models. Typically ignored, these end-uses usually represent between 13% and 44% of the total electricity consumption in an office building, according to Energy Consumption Guide 19. Currently there is little data available related to the electricity consumption of small power equipment in the context of office buildings. Existing data published in CIBSE Guide F is over a decade old and the use of office equipment and its associated technologies has changed significantly over this period. This lack of up-to-date benchmarks makes it increasingly difficult for designers to include small power consumption accurately within in their energy models. Following a detailed review of existing benchmarks for small power in office buildings, this paper presents a set of monitored data for a range of equipment commonly found in contemporary office buildings. Key metrics include details of power consumption and hours-in-use for both ICT equipment and kitchen appliances. In addition, a comparison of different laptops of varying specifications is provided and their subsequent impact on productivity is also discussed

Assessing the impact of occupant behaviour on electricity consumption for lighting and small power in office buildings

Lighting and small power will typically account for more than half of the total electricity consumption in an office building. Significant variations in electricity used by different tenants suggest that occupants can have a significant impact on the electricity demand for these end-uses. Yet current modelling techniques fail to represent the interaction between occupant and the building environment in a realistic manner. Understanding the impact of such behaviours is crucial to improve the methodology behind current energy modelling techniques, aiming to minimise the significant gap between predicted and in-use performance of buildings. A better understanding of the impact of occupant behaviour on electricity consumption can also inform appropriate energy saving strategies focused on behavioural change. This paper reports on a study aiming to assess the intent of occupants to switch off lighting and appliances when not in use in office buildings. Based on the Theory of Planned Behaviour, the assessment takes the form of a questionnaire and investigates three predictors to behaviour individually: 1) behavioural attitude; 2) subjective norms; 3) perceived behavioural control. The paper details the development of the assessment procedure and discusses preliminary findings from the study. The questionnaire results are compared against electricity consumption data for individual zones within a multi-tenanted office building. Initial results demonstrate a statistically significant correlation between perceived behavioural control and energy consumption for lighting and small power

Práticas de comensalidade no âmbito familiar de crianças de 2 a 9 anos de idade durante a pandemia do Covid-19

ABSTRACT   Objective: to evaluate practices of commensality within the family and possible changes in the eating routine of children between 2 and 9 years during the COVID-19 pandemic. Method: a cross-sectional study was carried out with parents and/or guardians of children aged between 2 and 9 years, through an online questionnaire, between November and December 2020. Practices of commensality were evaluated as recommended in the Food Guide for the Brazilian Population. Results: among the 517 participating families, regular meals were observed: breakfast (79.1%), lunch (98.6%), afternoon snack (88, 6%), and dinner (91.5%). Most children had defined times to have meals (82.6%), but more than half consumed snacks between main meals (53%). Lunch (83.0%) and dinner (80.1%) were taken with the family, sitting at the table (83.4%) and sharing the same foods (89.9%). Regarding the dietary changes caused by the pandemic, 50.5% of the families reported that there was no change, however, among the families that reported it, 52.3% considered it was for the better. The frequency of homemade preparations increased in 65.8% of the families, with lunch (82.6%) and dinner (78.1%) being prepared between 5-7 times a week. Conclusion: the practices of commensality were present daily in most of household, with little expression only attention to food. Regarding the eating routine, the social distance caused by the COVID-19 pandemic seems to have had a positive impact. Keywords: food guide, child, COVID-19, family, mealsObjetivo: avaliar práticas de comensalidade no âmbito familiar e possíveis mudanças na rotina alimentar, de crianças entre 2 e 9 anos de idade durante a pandemia do COVID-19. Métodos: estudo transversal realizado com pais e/ou responsáveis de crianças entre 2 e 9 anos, por meio de questionário online, entre novembro e dezembro de 2020. Foram avaliadas as práticas de comensalidade conforme o recomendado no Guia Alimentar Para a População Brasileira. Resultados: dentre as 517 famílias participantes, no que se refere às práticas de comensalidade, foi observada a realização das refeições com regularidade: café da manhã (79,1%), almoço (98,6%), lanche da tarde (88,6%) e jantar (91,5%). A maior parte das crianças possuía horários definidos para realizar as refeições (82,6%), porém mais da metade consumia alimentos entre as refeições (53%). As refeições principais, tais como almoço (83,0%) e jantar (80,1%), eram realizadas em companhia da família, sentados à mesa (83,4%) e compartilhando os mesmos alimentos (89,9%). Com relação as mudanças alimentares provocadas pela pandemia, 50,5% das famílias relataram não ter ocorrido mudança, porém, entre as famílias que relataram, 52,3% considera que foi para melhor. Ainda, a frequência das preparações caseiras aumentou em 65,8% das famílias, sendo o almoço (82,6%) e o jantar (78,1%) preparado entre 5-7 vezes por semana. Conclusão: as práticas de comensalidade estavam presentes no dia a dia da maioria das famílias, sendo pouco expressiva apenas a atenção ao alimento. No que tange a rotina alimentar, o distanciamento social provocado pela pandemia do COVID-19 parece ter gerado um impacto positivo.   Palavras-chave: Guias alimentares. Criança. COVID-19. Família. Refeições

Building Performance Assessment Protocol for Timber Dwellings – Conducting Thermography Tests on Live Construction sites

This paper introduces the pan-Wales (UK) Home-Grown Homes (HGH) project (2018 to 2020) which focusses on three areas of improvement for delivering high performance, affordable and healthy homes. The HGH project is funded by Powys County Council, through the European Regional Development Fund’s Agricultural Stream. The HGH project is being delivered by Woodknowledge Wales in a consortium with Cardiff Metropolitan University (CMU), TRADA and Coed Cymru, with seven work packages. ‘More and Better Homes from Wood’ (work package (WP) WP3) focusses on the assessment of building performance for dwellings using timber, and is being delivered by a multi-disciplinary team at CMU through the Sustainable and Resilient Built Environment (SuRBe) group. This paper discusses the context and need for the HGH project as Wales launched its low carbon agenda in March 2019. The focus of this paper on introducing the building performance assessment (BPA) protocol to be implemented by SuRBe across several housing case studies in Wales, through the design, in-construction and occupancy phases, to address thermal and fire (TaF) performance issues, and impacts on occupants’ quality of life, comfort and safety. Preliminary results of in-construction testing on a live construction site are presented, with the challenges of conducting thermography tests whilst construction is in progress and weather conditions in spring in the UK (April 2019). This paper will be useful for academics, architects, building contractors, housing developers and professionals undertaking building performance assessment and evaluation on live construction sites

O lazer de praticantes de basquete em cadeira de rodas / The leisure of whellchair basketball players

Esta pesquisa teve como objetivo identificar os conteúdos culturais de lazer físico-esportivo e virtual acerca das práticas corporais de pessoas com deficiência praticantes de Basquete em Cadeira de Rodas. Trata-se de uma pesquisa exploratória realizada com treze pessoas a partir da aplicação de questionários. Os resultados expressam a falta de formação escolar para o lazer, a escassez de oferta de práticas de lazer físico-esportivas e conexão entre os interesses de lazer físico-esportivos e virtuais