Housing as a modifier of air contaminant and temperature exposure in Great Britain: A modelling framework

This paper presents the development of a modelling framework that quantifies the modifying effect of dwelling characteristics on exposure to indoor air pollution and excess temperature. A georeferenced domestic building stock model of Great Britain was created using national housing surveys, historical weather, and local terrain data. Dynamic building performance simulation was applied to estimate indoor air pollution and overheating risk metrics at the individual building level. These metrics were then aggregated at various geographic units and mapped across Britain within a Geographic Information System (GIS) environment to compare spatial trends. Results indicate that flats and newly built properties are characterised by lower indoor air pollution from outdoor sources, but higher air pollution from indoor sources. Flats, bungalows and newly built, more airtight dwellings are found to be more prone to overheating. Consequently, urban populations may experience higher levels of pollution from indoor sources and overheating resulting from the higher prevalence of flats in cities

Comfort driven adaptive window opening behaviour and the influence of building design

It is important to understand and model the behaviour of occupants in buildings and how this behaviour impacts energy use and comfort. It is similarly important to understand how a buildings design affects occupant comfort, occupant behaviour and ultimately the energy used in the operation of the building. In this work a behavioural algorithm for window opening developed from field survey data has been implemented in a dynamic simulation tool. The algorithm is in alignment with the proposed CEN standard for adaptive thermal comfort. The algorithm is first compared to the field study data then used to illustrate the impact of adaptive behaviour on summer indoor temperatures and heating energy. The simulation model is also used to illustrate the sensitivity of the occupant adaptive behaviour to building design parameters such as solar shading and thermal mass and the resulting impact on energy use and comfort. The results are compared to those from other approaches to model window opening behaviour. The adaptive algorithm is shown to provide insights not available using non adaptive simulation methods and can assist in achieving more comfortable and lower energy buildings

Energy simulations of a transparent-insulated office facade retrofit in London, UK

Purpose – Transparent insulation materials (TIMs) have been developed for application to building facades to reduce heating energy demands of a building. The purpose of this research is to investigate the feasibility of TI-applications for high-rise and low rise office buildings in London, UK, to reduce heating energy demands in winter and reduce overheating problems in summer. Design/methodology/approach – The energy performance of these office building models was simulated using an energy simulation package, Environmental Systems Performance-research (ESP-r), for a full calendar year. The simulations were initially performed for the buildings with conventional wall elements, prior to those with TI-systems (TI-walls and TI-glazing) used to replace the conventional wall elements. Surface temperatures of the conventional wall elements and TI-systems, air temperature inside the 20mm wide air gaps in the TI-wall, dry-bulb zone temperature and energy demands required for the office zones were predicted. Findings – Peak temperatures of between 50 and 70°C were predicted for the internal surface of the TI-systems, which clearly demonstrated the large effect of absorption of solar energy flux by the brick wall mass with an absorptivity of 90 percent behind the TIM layer. In the office zones, the magnitude of temperature swings during daytime was reduced, as demonstrated by a 10 to 12 h delay in heat transmission from the external façade to the office zones. Such reduction indicates the overheating problems could be reduced potentially by TI-applications. Originality/value – This research presents the scale and scope of design optimisation of TI-systems with ESP-r simulations, which is a critical process prior to applications to real buildings

Adaptive Comfort Models Applied to Existing Dwellings in Mediterranean Climate Considering Global Warming

Comfort analysis of existing naturally ventilated buildings located in mild climates, such as the ones in the Mediterranean zones, offer room for a reduction in the present and future energy consumption. Regarding Spain, most of the present building stock was built before energy standards were mandatory, let alone considerations about global warming or adaptive comfort. In this context, this research aims at assessing adaptive thermal comfort of inhabitants of extant apartments building in the South of Spain per EN 15251:2007 and ASHRAE 55-2013. The case study is statistically representative housing built in 1973. On-site monitoring of comfort conditions and computer simulations for present conditions have been carried out, clarifying the degree of adaptive comfort at present time. After that, additional simulations for 2020, 2050, and 2080 are performed to check whether this dwelling will be able to provide comfort considering a change in climate conditions. As a result, the study concludes that levels of adaptive comfort can be considered satisfactory at present time in these dwellings, but not in the future, when discomfort associated with hot conditions will be recurrent. These results provide a hint to foresee how extant dwellings, and also dwellers, should adapt to a change in environmental conditions

Regulations and robust low-carbon buildings

Building regulations and associated calculation methods have been rapidly evolving, driven in Europe by the European Union Energy Performance of Buildings Directive. As an example, the current UK regulations are explored in relation to buildings that are naturally ventilated, mechanically ventilated, or mechanically ventilated and cooled. The UK regulatory energy and carbon calculation methods are investigated using a standard office design with typical, best practice, and advanced building fabric and systems applied. The criteria and calculations for demonstrating avoidance of excessive temperatures in buildings that have no mechanical cooling are also explored. Observations are made on how the regulations may influence future adoption of mechanical cooling. Current regulatory methods can be subjective and limited in scope. For example, they do not include adaptive comfort criteria or uncertainties in parameters such as occupant behaviour, climate, internal gains from equipment, etc. A design methodology is proposed that addresses these issues and provides a capability parameter to quantify robustness. This capability parameter allows comparison of design options and provides an indication to building users of the limitations to a building's use beyond which mitigating action would have to be taken for performance to be maintained

Predicting the Impact of Climate Change on Thermal Comfort in A Building Category: The Case of Linear-type Social Housing Stock in Southern Spain

The Climate Change scenario projected by the IPCC for the year 2050 predicts noticeable increases in temperature. In severe summer climates, such as the Mediterranean area, this would have very negative e ects on thermal comfort in the existing housing stock, given the current high percentage of dwellings which are obsolete in energy terms and house a population at serious risk of energy poverty. The main aim of this paper is to generate a predictive model in order to assess the impact of this future climate scenario on thermal comfort conditions in an entire building category. To do so, calibrated models representing linear-type social multi-family buildings, dating from the post-war period and located in southern Spain, will be simulated extensively using transient energy analyses performed by EnergyPlus. In addition, a sensitivity analysis will be performed to identify the most influential parameters on thermal discomfort. The main results predict a generalized deterioration in indoor thermal comfort conditions due to global warming, increasing the average percentage of discomfort hours during the summer by more than 35%. This characterization of the future thermal behaviour of the residential stock in southern Spain could be a trustworthy tool for decision-making in energy retrofitting projects which are so badly needed. To do so, further work is required on some limitations of this model so that di erent user profiles and typologies can be represented in detail and an economic assessment can be included

Assessment of Indoor Environmental Quality for Retrofitting Classrooms with An Egg-Crate Shading Device in A Hot Climate

In the Mediterranean climate, a large number of educational buildings suffer from discomfort due mostly to energy-deficient thermal envelopes and a lack of cooling systems. Impending climate change is expected to worsen overheating in classrooms, especially during heatwave periods. Therefore, the protection of window openings to reduce incident solar radiation while maintaining adequate indoor environmental quality must be considered a necessary key focus. The main objective of this research is to assess the influence of an egg-crate shading device on the indoor environmental quality of a classroom in Southern Spain. To do so, two classrooms—with and without this shading device—were simultaneously monitored over a whole year. The implementation of an egg-crate shading device allowed for a significant reduction of the incident solar radiation, both in summer and mid-season (around 45–50%), which objectively slightly conditioned indoor operative temperatures. Given the noticeable influence of the user patterns observed, indoor illuminance was also improved, as the rolling shutters tended to be opened at higher aperture levels

A three-stage optimization methodology for envelope design of passive house considering energy demand, thermal comfort and cost

Due to reducing the reliance of buildings on fossil fuels, Passive House (PH) is receiving more and more attention. It is important that integrated optimization of passive performance by considering energy demand, cost and thermal comfort. This paper proposed a set three-stage multi-objective optimization method that combines redundancy analysis (RDA), Gradient Boosted Decision Trees (GBDT) and Non-dominated sorting genetic algorithm (NSGA-II) for PH design. The method has strong engineering applicability, by reducing the model complexity and improving efficiency. Among then, the GBDT algorithm was first applied to the passive performance optimization of buildings, which is used to build meta-models of building performance. Compared with the commonly used meta-model, the proposed models demonstrate superior robustness with the standard deviation at 0.048. The optimization results show that the energy-saving rate is about 88.2% and the improvement of thermal comfort is about 37.8% as compared to the base-case building. The economic analysis, the payback period were used to integrate initial investment and operating costs, the minimum payback period and uncomfortable level of Pareto frontier solution are 0.48 years and 13.1%, respectively. This study provides the architects rich and valuable information about the effects of the parameters on the different building performance