Review on Time-Integrated Overheating Evaluation Methods for Residential Buildings in Temperate Climates of Europe

peer reviewedOverheating exposure over time can lead to discomfort, productivity reduction, and health issues for the occupants in buildings. The time-integrated overheating evaluation methods are introduced to describe, in a synthetic way, the extent of overheating over a span of time and predict the uncomfortable phenomena. This paper reviews the time-integrated overheating evaluation methods that are applicable to residential buildings in temperate climates of Europe. We critically analyze the methods found in (i) 11 international standards, namely, EN 15251 (2006), EN 16798 (2019), ISO 7730 (2004), ISO 17772 (2017–2018), ASHRAE 55 (2017), ASHRAE 55 (2020), CIBSE Guide A (2006), CIBSE TM52 (2013), CIBSE Guide A (2015), CIBSE TM59 (2017), and Passive House (2015), (ii) five national building codes based on the Energy Performance of Building Directive (EPBD) in Belgium, France, Germany, the UK, and the Netherlands, and (iii) two studies in the scientific literature. For each method, we present the thermal comfort models along with the time-integrated overheating indices and criteria. The methods are analyzed according to some key measures in order to identify their scope, strength, and limitations. We found that most standards recommend the static comfort models for air-conditioned buildings and the adaptive comfort models for non-air-conditioned ones. We also found a promising method based on three indices, namely, Indoor Overheating Degree (IOD), Ambient Warmness Degree (AWD), and overheating escalation factor (aIOD=AWD) that allows for a multi-zonal and climate change-sensitive overheating assessment. Finally, some guidance is provided for practice and future developments.[OCCuPANt] Impacts of climate change on buildings in Belgium during summe

Comparison of overheating risk in nearly zero-energy dwelling based on three different overheating calculation methods

peer reviewedThis study aims to inform building designers about overheating risks in nearly zero-energy dwelling and the importance of calculation methods. Three overheating risk indicators are selected and compared, comprising 1) the EPBD overheating indicator, 2) the Passive House overheating indicator, and 3) the ambient warmness degree and indoor overheating degree indicators developed by Hamdy et al. (2017) (Hamdy et al., 2017a). The third overheating calculation method represents the latest state-of-the-art method for overheating assessment. With the help of the EnergyPlus energy modeling program, a calibrated building energy model was created. Annual simulations took place for a typical meteorological year comparing overheating risk according to three calculation approaches. Results confirm a 216% difference in the overheated hours between the Energy Performance of Buildings Directive (EPBD) method and the used method of Hamdy et al. 2017. Results emphasize the need to improve the Belgian EPBD calculation method and integrate long-term thermal discomfort indicators to represent climate change and overheating risks in dwellings. Key Innovations Overheating risk estimation is calculated based on three different calculation methods, and results are compared One of the overheating calculation method takes into account future climate change scenarios and applies long-term thermal comfort evaluation indicators The findings urge the call for a new standardised wat to calculate overheating within the EU Energy Performance of Buildings Directive (EPBD) Practical Implications This paper provides a basis to integrate a new overheating calculation method in the EPBD tools in Belgium and other EU member states.[OCCuPANt] Impacts of climate change on buildings in Belgium during summe

Application of Simulation-Based Framework to Evaluate Performance of an Optimized Nearly Zero Energy Dwelling During Heatwaves in Belgium

peer reviewed[OCCuPANt] Impacts of climate change on buildings in Belgium during summe

A systematic review on role of humidity as an indoor thermal comfort parameter in humid climates

peer reviewedThermal discomfort over time can lead to unproductivity and health issues for the occupants. Like operative temperature, humidity is an important parameter that affects thermal comfort and occupant health. This paper analyzed how humidity was incorporated into spatial and person alized thermal comfort assessments and models. In addition, the paper studied different indoor thermal comfort indices in terms of index type and time temporality. The study found that most standards and guidelines recommended a fixed upper and lower threshold for humidity for spatial assessment. For personalized assessments, the humidity was indirectly coupled through evaporative heat losses in most physiological and psychological models. In addition, transient processes like metabolic activities that changed in warm temperatures and humidities also influenced human comfort perception. The existing indoor thermal comfort indices used a point-in-time approach in terms of time temporality. Based on these findings, this paper suggested a spatial assessment for early-stage building design and a personalized assessment for the post-occupancy stage. In addition, this paper recommended a time-integrated and multizonal hygrothermal discomfort indicator that should incorporate both operative temperature and relative humidity in the future. Finally, the paper provides a set of suggestions and aspirations for practice and research based on the study findings.Project SurChauff

Simulation-based framework to evaluate resistivity of cooling strategies in buildings against overheating impact of climate change

Over the last decades overheating in buildings has become a major concern. The situation is expected to worsen due to the current rate of climate change. Many efforts have been made to evaluate the future thermal performance of buildings and cooling technologies. In this paper, the term “climate change overheating resistivity” of cooling strategies is defined, and the calculation method is provided. A comprehensive simulation-based framework is then introduced, enabling the evaluation of a wide range of active and passive cooling strategies. The framework is based on the Indoor Overheating Degree (IOD), Ambient Warmness Degree (AWD), and Climate Change Overheating Resistivity (CCOR) as principal indicators allowing a multi-zonal approach in the quantification of indoor overheating risk and resistivity to climate change. To test the proposed framework, two air-based cooling strategies including a Variable Refrigerant Flow (VRF) unit coupled with a Dedicated Outdoor Air System (DOAS) (C01) and a Variable Air Volume (VAV) system (C02) are compared in six different locations/climates. The case study is a shoe box model representing a double-zone office building. In general, the C01 shows higher CCOR values between 2.04 and 19.16 than the C02 in different locations. Therefore, the C01 shows superior resistivity to the overheating impact of climate change compared to C02. The maximum CCOR value of 37.46 is resulted for the C01 in Brussels, representing the most resistant case, whereas the minimum CCOR value of 9.24 is achieved for the C02 in Toronto, representing the least resistant case.[OCCuPANt] Impacts of climate change on buildings in Belgium during summe

Historical and future weather data for dynamic building simulations in Belgium using the regional climate model MAR: typical and extreme meteorological year and heatwaves

peer reviewedAbstract. Increasing temperatures due to global warming will influence building, heating, and cooling practices. Therefore, this data set aims to provide formatted and adapted meteorological data for specific users who work in building design, architecture, building energy management systems, modelling renewable energy conversion systems, or others interested in this kind of projected weather data. These meteorological data are produced from the regional climate model MAR (Modèle Atmosphérique Régional in French) simulations. This regional model, adapted and validated over Belgium, is forced firstly, by the ERA5 reanalysis, which represents the closest climate to reality and secondly, by three Earth system models (ESMs) from the Sixth Coupled Model Intercomparison Project database, namely, BCC-CSM2-MR, MPI-ESM.1.2, and MIROC6. The main advantage of using the MAR model is that the generated weather data have a high resolution (hourly data and 5 km) and are spatially and temporally homogeneous. The generated weather data follow two protocols. On the one hand, the Typical Meteorological Year (TMY) and eXtreme Meteorological Year (XMY) files are generated largely inspired by the method proposed by the standard ISO15927-4, allowing the reconstruction of typical and extreme years, while keeping a plausible variability of the meteorological data. On the other hand, the heatwave event (HWE) meteorological data are generated according to a method used to detect the heatwave events and to classify them according to three criteria of the heatwave (the most intense, the longest duration, and the highest temperature). All generated weather data are freely available on the open online repository Zenodo (https://doi.org/10.5281/zenodo.5606983, Doutreloup and Fettweis, 2021) and these data are produced within the framework of the research project OCCuPANt (https://www.occupant.uliege.be/ (last access: 24 June 2022)​​​​​​​ – ULiège).ARC OCCuPANt7. Affordable and clean energy11. Sustainable cities and communities13. Climate actio

IEA EBC Annex 80 - Dynamic simulation guideline for the performance testing of resilient cooling strategies: Version 2

The objective of Annex 80 is to develop, assess and communicate solutions for resilient cooling. The systematic assessment of resilient cooling strategies is one of the main activities of Annex 80. The previous approach for assessing the resilience of cooling strategies is mainly based on qualitative comparison and based on results from individual research, which lacks common boundary conditions and universal indicators for resilience evaluation. This study aims to provide a consistent approach for assessing the resilience of different cooling strategies by dynamic simulation. Various cooling strategies will be tested on the reference buildings under present and future weather conditions in different climate zones, and proposed key performance indicators will be applied to evaluate summertime overheating risk and climate resistance of cooling strategies.02IEA Annex 80 – Resilient Cooling of Building

Impact of climate change on nearly zero-energy dwelling in temperate climate: Time-integrated discomfort, HVAC energy performance, and GHG emissions

peer reviewedGlobal warming is widely recognized to affect the built environment in several ways. This paper projects the current and future climate scenarios on a nearly zero-energy dwelling in Brussels. Initially, a time-integrated discomfort assessment is carried out for the base case without any active cooling system. It is found that overheating risk will increase up to 528%, whereas the overcooling risk will decrease up to 32% by the end of the century. It is also resulted that the overheating risk will overlap the overcooling risk by 2090s under high emission scenarios. Subsequently, two commonly applied HVAC strategies are considered, including a gas-fired boiler + an air conditioner (S01) and a reversible air-to-water heat pump (S02). In general, S02 shows ∼6–13% and 15–27% less HVAC primary energy use and GHG emissions compared to S01, respectively. By conducting the sensitivity analysis, it is found that the choice of the HVAC strategy, heating set-point, and cooling set-point are among the most influential parameters determining the HVAC primary energy use. Finally, some future recommendations are provided for practice and future research.[OCCuPANt] Impacts of climate change on buildings in Belgium during summe

Resilient cooling strategies – A critical review and qualitative assessment

The global effects of climate change will increase the frequency and intensity of extreme events such as heatwaves and power outages, which have consequences for buildings and their cooling systems. Buildings and their cooling systems should be designed and operated to be resilient under such events to protect occupants from potentially dangerous indoor thermal conditions. This study performed a critical review on the state-of-the-art of cooling strategies, with special attention to their performance under heatwaves and power outages. We proposed a definition of resilient cooling and described four criteria for resilience—absorptive capacity, adaptive capacity, restorative capacity, and recovery speed —and used them to qualitatively evaluate the resilience of each strategy. The literature review and qualitative analyses show that to attain resilient cooling, the four resilience criteria should be considered in the design phase of a building or during the planning of retrofits. The building and relevant cooling system characteristics should be considered simultaneously to withstand extreme events. A combination of strategies with different resilience capacities, such as a passive envelope strategy coupled with a low-energy space-cooling solution, may be needed to obtain resilient cooling. Finally, a further direction for a quantitative assessment approach has been pointed out

Typical and extreme weather datasets for studying the resilience of buildings to climate change and heatwaves

peer reviewedWe present unprecedented datasets of current and future projected weather files for building simulations in 15 major cities distributed across ten climate zones worldwide. The datasets include ambient air temperature, relative humidity, atmospheric pressure, direct and diffuse solar irradiance, and wind speed at hourly resolution, which are essential climate elements needed to undertake building simulations. The datasets contain typical and extreme weather years in the EnergyPlus weather file (EPW) format and multiyear projections in comma-separated value (CSV) format for three periods: historical (2001-2020), future mid-term (2041-2060), and future long-term (2081-2100). The datasets were generated from projections of one regional climate model, which were bias-corrected using multiyear observational data for each city. The methodology used makes the datasets among the first to incorporate complex changes in the future climate for the frequency, duration, and magnitude of extreme temperatures. These datasets, created within the IEA EBC Annex 80 “Resilient Cooling for Buildings”, are ready to be used for different types of building adaptation and resilience studies to climate change and heatwaves.11. Sustainable cities and communitie