Thermal Comfort In Winter Research Articles

Variability in thermal comfort and behavior of elderly individuals with different levels of frailty in residential buildings during winter

Research on the indoor thermal comfort of elderly individuals has become increasingly detailed, yet studies focusing on the impact of health levels on elderly thermal comfort are still relatively scarce. Due to aging and various chronic diseases, elderly individuals exhibit different physical states, affecting their physiological regulatory functions in response to thermal environmental changes. This study aimed to validate the impact of health levels on elderly thermal comfort and behavior during winter, by employing the Fried frailty assessment method. A survey was conducted in the HSCW regions of China, gathering 1437 valid questionnaires. The analysis revealed that frailty significantly impacts the winter thermal comfort and behavior of the elderly. Specific findings include: 1) Frailer elderly individuals express greater complaints about indoor environments; 2) Frailer elderly are more dependent on heating devices; 3) Frailer elderly have higher rates of closing windows with higher Tout prompting window closure. The Tout prompting non-frailty elderly to completely close windows is 8.1°C, while for pre-frail and frail elderly, it is 16.7°C and 16.0°C, respectively; 4) Frailer elderly individuals exhibit higher Icl, with median values of 1.56 clo for non-frail, 1.68 clo for pre-frail, and 1.71 clo for frail elderly; 5) Frailer elderly individuals have lower MR daily, with median metabolic rates of 1.71 met for non-frail, 1.42 met for pre-frail, and 1.17 met for frail. This study found that the level of frailty significantly impacts the winter thermal comfort and behavior of the elderly and should be considered in future elderly-friendly architectural designs.

Field Study on Winter Thermal Comfort of Occupants of Nursing Homes in Shandong Province, China

Field Study on Winter Thermal Comfort of Occupants of Nursing Homes in Shandong Province, China

Assessing the winter indoor environment with different comfort metrics in self-built houses of hot-humid areas: Does undercooling matter for the elderly?

Thermal comfort in housing is vital for well-being. Despite hot and humid regions experiencing shorter cold periods compared to heatwaves, vulnerable populations are susceptible to threats from cold snaps. However, existing research overlooks undercooling risks in hot regions during winter. This study examines self-built houses in densely populated, hot and humid areas, mainly occupied by elderly residents. We conducted an on-site measurement recording hourly indoor air temperature, humidity, and black globe temperature during wintertime. Two thermal comfort metrics (aPMV and adaptive regression model) and two resilience metrics (SET degree-hour, Hours of Safety) were used to quantify thermal conditions during cold periods under current and future climate conditions. The results show that undercooling hours in recent years exceed 90 % of wintertime using aPMV index and adaptive regression models. Under future climate scenarios (Representative Concentration Pathways), undercooling hours only decrease by 10 %–25 % from 2020 to 2100 across all metrics. Extreme cold events in 2018 saw SET degree-hours double the thermal resilience threshold, while they pose health risks to the elderly for up to 21 days according to the HOS metrics. This study aims to identify the importance of addressing winter thermal comfort in hot and humid regions and to assess the risk posed by cold snaps to vulnerable populations. By quantifying these risks, the study contributes to better decision-making regarding hot-humid region housing thermal retrofit strategies for architects, engineers, and other stakeholders.

Evaluating Thermal Comfort and Overheating Risks in A Social Housing Prototype: As Built Versus Retrofit Scenarios

Climate change has highlighted the importance of thermal comfort and its health-related outcomes, particularly for the most vulnerable members of society living in social housing. Due to their vulnerable living conditions, low-income people are more exposed to negative outcomes of overheating and cold indoor temperatures in buildings. Previous studies suggest that there is a significant risk of overheating in retrofitted buildings both for the current and future weather scenarios. The UK government has introduced new building regulations to assess and limit the risk of overheating in new buildings; however, there is still a need to assess and improve conditions for existing and retrofitted properties. This study aims to evaluate the effect of retrofit strategies on thermal comfort and the risk of overheating in social housing under current and future climatic conditions. A typical case study building was simulated in DesignBuilder to assess thermal comfort conditions for upgraded building fabric to Part L of the UK building regulations and Passive House standards. The summer results were analyzed according to CIBSE TM59 while the Predicted Mean Vote index (PMV) was used for winter analysis. Findings revealed that the south-facing bedrooms are most exposed to overheating. Risk of overheating significantly increased for the future weather scenarios by up to 10 times while winter thermal comfort improved for the retrofitted scenarios.

Multi-objective optimization for generative morphological design using energy and comfort models with a practical design of new rural community in China

In recent years, the development of new rural communities has emerged as a pivotal new trend in china, aimed at enhancing energy efficiency and residential comfort in rural regions. This study introduces a multi-objective optimization design framework for the morphological design of residential area, with a focus on performance objectives such as building energy use intensity, summer thermal comfort, and winter thermal comfort. A case study of a new rural community design project in Hongnan Village, Yancheng City, was conducted. Utilizing the Rhino-Grasshopper parametric platform, this study undertook parametric modeling, performance simulation, and multi-objective optimization to receive the Pareto-optimal solutions. ParetoResults indicate that in the Pareto-optimal morphology scheme for the Hongnan Village community, open spaces are predominantly located on the upwind side with respect to the prevailing summer winds of the site. The number of duplex houses is often 28, and the building orientations are predominantly aligned at 23°, mirroring the direction of the surrounding structures. There is a significant correlation between residential unit configuration, building spacing, and energy use intensity, with correlation coefficients of 0.53 and −0.43, respectively. This study would like to offer valuable insights into the energy-efficient design of new rural communities, thereby contributing to the creation of a more sustainable and habitable rural living environment.

Exploring place attachment: Insights from post-Gorkha earthquake resettlement planning in Nepal

This study investigates the relationship between place attachment and resettlement planning in Nepal post the Gorkha Earthquake of 2015. Focusing on functional place dependence, it analyses place attachment within the Panipokhari Integrated Settlement, designed for the Thami community in Dolakha district. Using "residential satisfaction" as a parameter to measure the influencing factors of place dependence, data were collected through a Likert scale survey, interviews, and observations. The analysis encompassed Cronbach's Alpha for reliability (α = 0.825), mean satisfaction scores for evaluation, and Spearman’s rank correlation to explore relationships between residential satisfaction parameters and place dependence factors. The study revealed significant correlations, highlighting varied influences on place attachment. Notably, social connectivity, represented by nearness to relatives (r = 0.720, p = 0.000), exhibited a strong positive correlation. Similarly, infrastructure amenities like electricity (r = 0.532, p = 0.000) displayed a relatively strong positive correlation, while access to health facilities (r = 0.447, p = 0.002) demonstrated a moderate positive correlation. Moreover, settlement planning components—kitchen gardens (r = 0.623, p = 0.000), open spaces (r = 0.578, p = 0.000), settlement layout (r = 0.549, p = 0.000), and cattle sheds (r = 0.574, p = 0.000)—significantly correlated with increased attachment. Additionally, housing design factors like immediate exterior spaces (r = 0.730, p = 0.000), spaces for life cycle rituals (r = 0.771, p = 0.000), and social events (r = 0.663, p = 0.000) and building performance factor winter thermal comfort (r = 0.606, p = 0.000)displayed substantial positive correlations. Acknowledging study limitations, it offers insights for planners and policymakers, stressing holistic approaches for sustainable resettlement. Future research should explore diverse factors and contexts, emphasizing the dynamic nature of place dependence. Ultimately, the study underscores the intricate relationship between satisfaction parameters and place attachment, urging comprehensive resettlement strategies.

Improvement of Human Comfort in Rural Cave Dwellings via Sunrooms in Cold Regions of China

Economic development limits the living quality of rural residents. In particular, the residential buildings in northern China generally have poor thermal comfort in winter, which affects the physical and mental health of residents. Because of the separation of rooms, residents who live in cave dwellings often have to enter and leave rooms in the course of their daily lives, which leads to worse thermal feelings in winter. Because of the low price and the wind insulation and heat storage, sunrooms are widely used in renovations of rural houses. The traditional purpose of the addition of a sunroom is to provide a buffer room between outdoor and indoor spaces. This manuscript focuses on improving the degree of thermal comfort by means of a sunroom connecting all rooms. This study selected two families with the same number of members and similar daily activities as the study cases. One of the families had a sunroom built to connect its bedroom, living room, and washroom. The household’s air temperature and human comfort were measured both on holidays and on workdays. It is demonstrated that adding a sunroom can significantly stabilize the thermal environment and increase the air temperature in both the bedroom and the living room. Adding a sunroom can increase the air temperature of a cave dwelling’s main room by 1.0 °C on workdays and 4.3 °C on holidays. A cave dwelling with a sunroom can also provide residents with a decent level of human comfort for 24.4% of their daily time on workdays and 39.1% of the time during holidays. This research demonstrates that a sunroom can not only increase the air temperature in cave dwellings but also enhance the stability of human comfort. The conclusion provides new renovation ideas for improving the living comfort of cave dwellings.

Indoor environmental quality in an Apulian kindergarten

Indoor environmental quality (IEQ) in school buildings is crucial for the health and well-being of students, educators, and staff. Poor air quality and inadequate thermal conditions compromise students’ comfort and can lead to potential long-term health issues. Since children’s comfort differs from adults’, it is important to consider surveys on IEQ in school buildings. For this reason, this paper focuses on air quality and thermal comfort in kindergartens in Italy. An IEQ monitoring campaign was conducted within a kindergarten, with data used for thermal comfort and IAQ analyses, including CO2 levels generated by occupants and thermal discomforting hours. The simulations of carbon dioxide levels showed that the amount of CO2 accumulated in the classrooms exceeds the threshold recommended by ASHRAE guidelines. During the winter seasons, CO2 levels are significantly higher than those accumulated in summer due to the limited ventilation practiced during the colder months. Moreover, thermal comfort analyses indicate that the summer season can be problematic due to overheating: 42% of the occupied hours during the monitoring period exceeded the temperature threshold, causing thermal discomfort for the occupants. The winter thermal comfort analyses demonstrated that heating systems are essential to maintain temperatures within comfort thresholds.

Effects of thermal stress on calf welfare

Cold and heat stress present welfare challenges for dairy calves. The consequences of thermal stress on biological functioning have been well documented, and many housing and management strategies have been evaluated to mitigate those detrimental impacts. In cold weather, mitigation strategies have largely focused on nutritional interventions or limiting heat loss with resources such as bedding or jackets. In hot weather, heat abatement strategies such as supplemental shade, increased environmental air exchange through passive ventilation, and forced air movement through mechanical ventilation have been evaluated. Recently in Wisconsin's continental climate, our group evaluated how 2 aspects of calf welfare—the needs for thermal comfort and social contact (i.e., pair or group housing vs. individual housing)—may align or conflict in winter and summer, respectively. In both seasons, calves pair-housed in outdoor hutches preferred social proximity. When 2 calves shared a hutch, the heat load was greater than for a single calf, which may be beneficial for thermal comfort in winter. In summer, the potential detriments from the additional heat load of 2 calves was mitigated with passive hutch ventilation, which calves preferred. Nonetheless, knowledge gaps remain regarding the impacts of thermal stress on calves' affective states, and much remains unknown about their preferences and motivations for specific thermal stress mitigation resources. Future research to address these gaps could improve our understanding of calf welfare and inform best practices for calf management.

Temporal Changes in Tourists’ Climate-Based Comfort in the Southeastern Coastal Region of Spain

In the context of climate change, where the average temperature has risen in recent decades on the Mediterranean coast of the Iberian Peninsula, bioclimatic indicators show an increase in thermal discomfort. This is especially relevant in regions with a clear focus on mass and seasonal sun and beach tourism, with a large number of tourists experiencing discomfort in hot and humid summer environments. The research analyses the temporal evolution (1967–2022) of the coasts of the provinces of Alicante and Murcia (Spain) using the Climate Comfort Index (CCI), divided into four different regions. Used are 14 coastal meteorological observatories divided into four regions. Trend analysis was performed using the Mann–Kendall (MKT) and Theil–Sen (TSE) tests. The results revealed a loss of climate comfort during the summer season (−0.3 to −0.4/decade), as well as an expansion of the warm period toward June and early September, with an increase of 38.7 days in “hot” thermal comfort. The increase in thermal discomfort in the summer is influenced by an increase in average temperature (0.5 to 0.7 °C/decade) and a reduction in the average relative humidity (−1.0 to −2.1%/decade) and wind speed (−0.2 to −0.9 km/h/decade). In the last 22 years (2000–2022), decreases (p ≤ 0.05) have been recorded in July and September (−0.2 to −0.4/decade), reaching “excessive heat” climatic comfort thresholds for the first time. Finally, there has been an increase in thermal comfort in winter, especially during December in recent years (2000–2022).

A Simulation Study of the Impact of Urban Street Greening on the Thermal Comfort in Street Canyons on Hot and Cold Days

The urban heat island effect has become a widely concerning issue worldwide. Many researchers have made great efforts to improve the summer thermal comfort of urban street canyons by optimizing street greening. Relatively less research has focused on how to improve the thermal comfort of street canyons by optimizing street greening during cold days. Many researchers have proposed strategies to improve the summer thermal comfort of street canyons using road greening. This may have a significant negative impact on the winter thermal comfort of street canyons due to the lack of consideration of the impact on hot and cold days simultaneously, especially when the road green space is mainly composed of evergreen tree species. We aimed to explore the impacts of urban street greening on thermal comfort on hot and cold days at the same time. We used Zhutang West Road in Changsha, China, as an example and built six different models to explore the impacts of the street vegetation types, number of street trees, tree heights, crown widths, and Leaf Area Index on the thermal comfort of the street canyon. In addition, we also considered the impact of different building features and wind directions on the thermal comfort of the street canyon. We employed ENVI-met (version 5.5.1) to simulate different urban street greening models. The results show that the model with a high tree canopy density, tall trees, large and dense crowns, and sufficient building shade has good thermal comfort on hot days (the average physiological equivalent temperature (PET) is 31.1 °C for the study period) and bad thermal comfort on cold days (the PET is 13.3 °C) when it is compared with the other models (the average PETs are 36.2 °C, 31.5 °C, 41.5 °C, 36.2 °C, and 35.5 °C, respectively, on hot days and for other models). In addition, the model with a very large number of short hedges has a positive impact on thermal comfort during hot days (the PET is 31.1 °C). The PET value of another comparable model which does not have hedges is 31.5 °C. Even if the model with a small building area has good ventilation, the small building shade area in the model has a more obvious impact and the model has relatively good thermal comfort during cold days (the PET is 14.2 °C) when it is compared to models with bigger building areas (the PET is 13.9 °C). In summer, when the wind is parallel to the direction of the street canyon, the wind speed in the street canyon is high and the model has relatively good thermal comfort (the PET is 35.5 °C) compared with another model which has different wind direction and lower wind speed at the street canyon (the PET is 36.2 °C). In winter, when the wind is perpendicular to the direction of the street canyon, buildings and trees have a strong windproof effect and this is beneficial to the improvement of thermal comfort (the PET is 15.3 °C for this model and 13.9 °C for another comparable model). This research lays a solid foundation and encourages people to think about the impact of building and tree composition and configuration on the thermal comfort of street canyons during hot and cold days simultaneously.

Study on Xiamen’s Spring and Winter Thermal Comfort of Outdoor Sports Space in the Residential Community

In humid subtropical areas, outdoor sports activities in winter and spring are very common. However, there is minimal research surrounding this topic, especially in terms of thermal comfort. This study explored the complex relationship between microclimate and human thermal comfort during various types of outdoor sports activities through a series of outdoor thermal experiments and analysis. The results indicated that (1) in winter and spring, the WBGT comfort threshold for outdoor sports space was 14.6–21.7 °C; (2) the WBGT comfort ranges when doing low-, moderate- and high-intensity physical activities were 13.7–26.2 °C, 14.5–24.0 °C, and 16.0–22.0 °C; (3) air temperature (Ta), G (global radiation) and relative humidity (RH) were the main thermal comfort influencing factors, which varied from the intensities of physical activities; (4) in winter, it was more comfortable to be slightly warm, while in spring, it was more comfortable to be neutral; (5) the ground materials, sunshine and vegetation coverage of outdoor sports space had a significant impact on adjusting Ta; (6) in addition to thermal comfort, factors such as time, weather, variety and quantity of outdoor sports spaces and facilities, high visual comfort, good accessibility, strong safety, regular maintenance of the space and facilities and the sharing level of outdoor sports spaces all had a major impact on outdoor sports activities; (7) semi-outdoor spaces with roofs should be considered next to outdoor sports spaces.

Differences in Outdoor Thermal Comfort between Local and Non-Local Tourists in Winter in Tourist Attractions in a City in a Severely Cold Region

The unique climate and the landscape of severely cold regions in winter attract many tourists. The outdoor thermal environment affects the space use and the tourist experience, becoming one of the key factors in the design of tourist attractions. The outdoor thermal comfort of tourists from different regions should be considered, but it has been poorly studied in winter in severely cold regions. This paper explores the differences in outdoor thermal comfort in winter between local and non-local tourists through the field measurement of the thermal environment and a questionnaire survey of thermal comfort at tourist attractions in Harbin, China. The results show that the proportion of local tourists who expect the air temperature and solar radiation to rise in winter is higher than that of non-local tourists. The thermal sensation vote of local tourists is generally higher than that of non-local tourists. When the Physiologically Equivalent Temperature (PET) < −6 °C, the thermal satisfaction of non-local tourists is higher than that of local tourists. When the PET value is −10 °C, the thermal comfort of non-local tourists is the highest. The thermal comfort decreases with the rise or fall of the PET value. When −28 °C < PET < −7 °C, the thermal comfort of non-local tourists is generally higher than that of local tourists. This paper provides a reference and evaluation basis for urban tourist attractions’ outdoor thermal environment design in severely cold regions.

Global sensitivity analysis based on multi-objective optimization of rural tourism building performance

Morphological design has significant impacts on the performance of rural tourism buildings (RTBs). Multi-objective optimization has been practiced for three prototypes of RTBs in Tianjin, China to explore the RTB design with better energy load, indoor daylighting and thermal comfort performance. However, making decisions from the solution set is still a challenging task for decision-makers. So post-optimization analysis is conducted in this study, and multi-objective optimization solution set of the three RTB types is investigated through global sensitivity analysis (GSA) on the platform of R studio. To begin with, correlation coefficients of the parameters are analyzed by Spearman and partial correlation coefficients methods, and strong correlation relationships are discovered among design parameters of RTBs. Afterwards, Genizi and random forest-based cforest methods are adopted for GSA towards different performance of RTBs, and comprehensive analysis is implemented for the results. Finally, it's found that the depth of frequently used space has significant impacts on annual, cooling and heating load, and daylighting of RTBs. Besides, the height of skylight is discovered to be key important parameter for both cooling and daylighting, and the width as well as the window to wall ratio of the heating space in winter have important influence on winter thermal comfort performance. Overall, the framework and methodology for GSA in post-optimization phase is put forward. The influential mechanism of morphological design parameters on energy load, daylighting and thermal comfort performance of RTBs is explored on basis of the multi-objective optimization solution set. This study not only supplies scientific suggestions for decision-making of RTBs in Tianjin, China, but also offers reference for RTB design and practice in similar regions of the world.

Health gains from home energy efficiency measures: The missing evidence in the UK net-zero policy debate

ObjectivesThis study examined the health gains from a programme of external wall insulation works to homes in south-west Scotland, and in particular the impact upon hospitalisations for respiratory and cardiovascular conditions. Furthermore, to consider how evidence on health outcomes could form part of the debate around actions to meet net-zero goals in the UK. Study designThis was a two-part study. Part one involved before-and-after interviews with 229 recipient households. The second part comprised an observational study of hospital admissions in 184 postcode areas. MethodsAcross three years, interviews collected thermal comfort and self-reported health data(Sf-36) in the winter months prior to installation, and again in follow-up interviews the next winter. Standarised monthly data on non-elective admissions for each set of conditions were compared between the intervention postcodes and the wider health board area over a ten year period. ResultsFollowing receipt of wall insulation, inability to achieve thermal comfort in winter reduced by two-thirds. Improvements in thermal comfort were associated with gains in physical health scores. Relative standardised admissions fell in the treatment areas, remaining lower than the district-wide standardised rate for the majority of a five year period, this effect ending during the Covid-19 pandemic. The impact on admissions was greater for respiratory conditions than for cardiovascular conditions. ConclusionA weak policy commitment to energy efficiency could be strengthened with further evidence of the cost-savings and reduced hospital bed demand resulting from insulations works. The potential health gain may also encourage more home owners to participate.

Research on Indoor Thermal Environment Analysis and Optimization Strategy of Rural Dwellings around Xi’an Based on PET Evaluation

Rural dwellings are an important group of residential buildings in China. With the continuous development of rural construction in China, the contradiction between the pursuit of a simple material space and the villagers’ demand for living quality, especially the indoor thermal comfort of rural dwellings, has become increasingly prominent. Therefore, it is particularly important to study the optimization strategies of the indoor thermal environment in rural dwellings. Current research on optimizing the indoor thermal environment of rural dwellings mainly focuses on analyzing the impact of individual factors, such as the envelope structures, building constructions, and building technology applications, but there is a lack of strategy development based on the comprehensive evaluation. This study aims to analyze the combined effects of multiple design elements on the indoor thermal environment and propose a comprehensive optimization strategy for rural dwellings. This study selects the rural dwellings around Xi’an as an example and establishes a basic model of the rural dwellings around Xi’an through field investigation and software simulation. Then, through univariate and compound-variable simulations, we analyze the influence of changes in passive architectural design indicators on the indoor physiological equivalent temperature (PET) of rural dwellings and obtain a comprehensive design indicator optimization strategy. This strategy can improve the indoor thermal comfort in winter and summer, especially in winter, achieving an average increase of 4.17 °C in the winter PET value and an average decrease of 0.66 °C in summer. This provides a reference for the design and renovation of rural dwellings in Xi’an and other rural areas in the cold regions of China.

Assessing Thermal Comfort Perception in the Context of Social Housing. Case Study in Northern Spain

The influence of people on building performance in terms of energy efficiency and environmental impact is becoming increasingly significant. It is essential to include users’ perspective, their comfort and satisfaction in decision making to ensure not only their well-being, but also the feasibility of interventions and the adequate performance of the building stock. Furthermore, understanding residents’ level of thermal satisfaction can enable more appropriate measures to improve the energy efficiency of buildings. Although there are several methods for studying thermal comfort, such as qualitative analyses based on surveys or perceived comfort indices such as PPD and PMV, thermal satisfaction is susceptible to the subjectivity of the responses. It may be necessary to contrast different indices or methods. This study aims to define an indicator that measures the level of thermal satisfaction of social housing occupants so that it can be contrasted with other methods of analysis of perceived comfort and can be replicated in different building contexts. A way to analyse users’ thermal satisfaction is proposed in a quantitative way, measured as the difference of the desired temperature and the perceived indoor temperature. The index is applied to a sample of 283 social housing dwellings in the Basque Country, Spain, with the data obtained via surveys that include questions on thermal comfort in winter and households’ characteristics. The thermal satisfaction has been analysed and the results have been contrasted with the perceived thermal comfort in winter and the household’s capacity to maintain the dwelling at the desired temperature. Moreover, it has been observed whether there may be energy vulnerabilities by contrasting the satisfaction result with the income and expenditure per person in the household. The obtained variable provides occupants’ opinion and perception to ensure the suitability of the solutions for improving the energy efficiency of the building and the thermal comfort. It is also possible to apply it to different building typologies and compare the results with other models of perceived thermal comfort.

Effects of constant and fluctuating temperature modes of foot heating on human thermal responses in cold environments

Heating demand has increased dramatically in winter in southern China. Foot heating pad, as a personal comfort system device enables to improve occupants’ thermal comfort in winter while consuming less energy. However, the research on the heating modes of these devices remains insufficient. The effects of fluctuating foot heating on thermal responses were compared to those of traditional constant heating in this study. A climate chamber experiment involving 16 subjects was conducted to assess physiological and psychological thermal responses under constant and fluctuating foot heating modes with equal total heating energy. Skin temperatures and thermal perception votes at three indoor temperature conditions of 8, 11, and 14 °C were collected and analyzed. The results indicate that the investigated parameters were significantly improved by foot heating, with foot skin temperature rose by 7 °C, foot thermal sensation rose by 2.7 levels, and overall thermal comfort rose by 0.4 level at least. Constant heating can improve skin temperature and thermal sensation to a higher extent than fluctuating heating in cold environments, especially when ambient temperature was lower than 12 °C. However, heating the foot alone cannot effectively improve overall thermal comfort in a cold environment below 12 °C. With ambient temperature between 13 and 17 °C, fluctuating heating can better avoid local overheating and ensure thermal acceptance rate larger than 90%, and fluctuating heating with high frequency and small amplitude is better than that with low frequency and large amplitude. Thus, the optimal fluctuating foot heating mode was recommended to be applied in cold environments higher than 13 °C.

How to ensure occupant comfort and satisfaction through deep building retrofit? Lessons from a Danish case study

The pace of building retrofit is expected to increase significantly in the coming decade if the European Union is to meet its ambitious climate targets. This study explores successes and challenges with current retrofit efforts, with focus on indoor environmental quality and occupants’ satisfaction with the technical installations. A survey, indoor environmental monitoring and semi-structured interviews were carried out in a Danish social housing area undergoing a deep energy retrofit. The retrofit considerably improved winter thermal comfort and indoor air quality, which was a great source of satisfaction for the occupants. Overheating was however identified as an important concern in summer. The mechanical ventilation units suffered from faults which caused discomfort, in particular dry air, noise and draft. Occupants lacked knowledge on ventilation and manual control over it, which led a share of them to mitigate discomfort in alternative ways, by obstructing diffusers or disconnecting the units. To avoid the risks linked to such behaviors, new retrofit efforts should pay particular attention to user-friendliness of technical installations, clear communication of technical information to the residents and a close monitoring of the installations’ performance and occupants’ satisfaction after move-in.

Thermal comfort in the Modern Movement — Evaluating​ the winter behavior of a housing building in Porto, Portugal

This study aims to examine how the original construction systems implemented in a modern movement apartment building affect its winter thermal comfort. The importance of analyzing the avant-garde and distinctive buildings of this period is linked to the need to define appropriate and specific strategies for their reuse, maintenance and restoration, in order to assess how these buildings can maintain their original integrity and identity. In this study, thermal measurements and simulations were carried out to check whether the indoor conditions meet today’s standards considering an adaptive comfort model. We can conclude that thermal passive comfort is essential to the concept of architectural space, shape and distribution of functions developed by the designers of our case study building. This research provides the basis for defining respectful restoration interventions in architectural heritage of the Modern Movement. It also tries to show that contemporary needs and requirements regarding thermal comfort can be achieved with the occupancy of the dwellings with minimal adjustments and interventions in the existing constructive systems.