The study aimed to assess the overheating vulnerability of an existing multi-apartment building built in 1971 in Podgorica, Montenegro. The building consists of 80 apartments and is mostly still in ...its original state. Firstly, the building was modelled in EneryPlus, and a parametric study was performed with jEPlus. The energy need for heating and cooling was simulated using parameters such as thermal insulation level, window properties, external surface solar absorptivity, shading activation set-point, and natural ventilation cooling intensity. Moreover, the energy need was determined for four different climate periods, namely for the current and three future periods up to the end of the 21
st
century under the RCP8.5 climate change scenario. The total number of building models equalled 648 for each of the four climate scenarios, resulting in 2,592 simulated cases. After that, the overheating vulnerability score was determined using the minimax regret method and cooling energy need as a performance indicator. The best retrofit action was determined by identifying the most favourable combination of the overheating vulnerability and total energy need. The results deliver the appropriate energy retrofit actions to limit the increase in overheating risk and provide for climate change adaptation of the multi-apartment building stock in Montenegro.
•Low energy use of single-family buildings can be assured solely by passive design.•Passive adaptation only partly counterbalances climate change effects on energy use.•Total energy use will decrease ...in cold and temperate and increase in warm climates.•The most effective long-term climate adaptation measure is applying smaller windows.•New buildings should be designed according to mid-term optima (2020/2050 period).
The presented study aims to clarify the implications of passive design measures on heating and cooling energy use of single-family residential buildings under European representative climates. In order to address this matter, different values of thermal transmittance (opaque and transparent), window to floor ratio, window distribution, shape factor, diurnal heat storage capacity, external opaque surface solar absorptivity and natural ventilation cooling rates were combined in 496,800 building energy models, which were simulated at eight locations. Because buildings are in use for many decades, the energy use simulations were made considering the projected climate change up to the end of the 21st century. The results delivered a set of the most effective passive design measures for achieving low energy use in buildings regarding climate type and period. A lower window to floor ratio was identified as the most universally applicable design measure to counterbalance the projected effect of a warming climate. In contrast, other measures vary according to climate type and studied period. Furthermore, it was concluded that it is difficult to neutralise the projected climate change effects on buildings' energy use, even when applying the best performing combination of passive design measures. However, reasonably low energy use can still be assured solely by passive building design, especially in oceanic, warm, and some temperate climate locations. Therefore, the identified trends in energy use and passive design measures represent the foundation for strategies and guidelines aimed at future-proof energy-efficient buildings.
The study deals with a three-storey log house located in the suburbs of Ljubljana, Slovenia (temperate climate). Firstly, the calibrated thermal model of the log house was defined. The calibrated ...model had an hourly NMBE between −2.12 % and 1.84 % and a CV(RMSE) between 3.16 % and 3.57 %. Then, the adaptive thermal comfort during the warmer part of the year was assessed according to EN 16798-1 and future climate (SRES A2 scenario). Additionally, various building-related and organisational measures for overheating prevention were evaluated. It was found that the most effective measures to prevent overheating are the organisational measures of shading activation and night ventilation. It was demonstrated that the efficiency of night ventilation would even improve over time. Thus, at the end of the 21
st
century, discomfort hours could be reduced by 67 % compared to the baseline. In contrast, building-related measures have a significant effect only when combined with organisational measures. Overall, in 2071–2100 adaptive thermal comfort was improved most when the measure of increased thermal insulation was coupled with shading and night ventilation, resulting in 1053 discomfort hours less than the baseline case.
Bioclimatic potential analysis is one of the starting points for bioclimatic building design. However, as climate changes are being brought into the spotlight, bioclimatic potential is being put into ...question as well, because traditionally used passive strategies at a specific location may no longer represent properly balanced approach. Therefore, the purpose of this paper was to systematically evaluate bioclimatic potential of the selected five locations. At these locations, bioclimatic potential was observed separately for each of the last five decades. In the second part, present and future energy performance of one bioclimatic and one non-bioclimatic real residential building was simulated. The results show that yearly balance between heating and cooling passive strategies changed through time in all the locations. For example, the use of overheating prevention strategies is becoming more significant than it used to be in the past. Specifically, the period of year when shading is needed to achieve thermal comfort increased by 2–7% points, depending on location. Energy performance analysis of the selected buildings showed that by 2050 both analysed buildings will become cooling dominated and that by 2050 the current design solutions in bioclimatic buildings will become irrelevant or at least extremely inefficient. In general, in temperate climate zone the prevailing bioclimatic strategies integrated in architecture focus on heating season. Therefore, bioclimatic strategies in a particular location must be re-evaluated in order to design new and retrofit existing energy efficient contemporary buildings with comfortable indoor thermal conditions.
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•Past, present and future bioclimatic potential at 5 locations was observed.•Due to climatic shifts a change in bioclimatic potential was identified.•Passive strategies for overheating prevention are gaining in importance.•Reducing building envelope U value might become less important in the future.•The results should be employed in future building energy performance policy.
•The impact of passive measures on heating and cooling was assessed using MLR.•A bioclimatic potential analysis is helpful for future-proofing of single-family homes.•The opaque envelope U-value was ...the most relevant for the total and heating energy use.•The window area was the most relevant for the cooling energy use in present and future.•The relevance diagrams of passive parameters for the energy use were introduced.
In the early phases of building design, it is essential to quantify the relevance of passive design measures in order to assure the desired thermal performance of buildings throughout their lifespan. In the present research work, the authors investigated the relevance of the selected passive design measures for heating and cooling energy use of single-family detached buildings at five European locations. To this end, a multiple linear regression analysis was performed, and least-squares estimates were used to identify the most relevant passive design measures under current and three future periods. The statistical analysis showed that the importance of passive design measures would change under the projected global warming effects. In general, the most relevant for the heating energy use of the analysed building models is the opaque envelope U value. Besides effective shading, the most relevant parameter affecting the cooling energy use is the window-to-floor ratio. Furthermore, relevance diagrams for the influence of passive design parameters on the resulting energy use under the climate change scenario and specific U values of the opaque envelope were defined. Building designers and policymakers can use them as design-support tool to find appropriate ways of converting the number of unknowns in future climate into information for designers and decision-makers to assure low vulnerability of the built environment to global warming.
Daylight is ever more recognised as a major synchroniser of circadian rhythms, linking us to the 24 h solar day. However, the time that urbanised humans spend outdoors has decreased substantially ...during the last century, which highlights the importance of appropriate indoor daylighting. Quality and quantity of daylight in indoor environments are primarily modulated by the characteristics of the building envelope. In this context, a combined in-situ experimental (Ljubljana, Slovenia) and simulation study of a cellular office model was executed in order to evaluate the impact of different glazing types and internal wall colours on the non-visual potential of daylight. In particular, the impact of seven glazing types and six different wall cover hues at three reflectance levels was determined. Among these, three glazing types and three wall colours of equal reflectance were further evaluated through diurnal simulations of the indoor luminous environment. Low-e glazing with high visual transmittance and blue coloured wall were indicated as combinations with the highest non-visual entrainment, while the opposite is true for the combination of bronze tinted solar protective glazing and orange walls. In general, a better non-visual environment can be achieved using materials characterised by higher spectrally neutral transmissivity or reflectance than with those characterised by spectrally non-neutral properties and of lower transmissivity or reflectance.
•Low-e glazing and blue coloured wall combination have highest non-visual potential.•Bronze tinted glazing and orange walls have lowest non-visual potential.•If possible, high transmitting glazing is recommended for typical cellular offices.•Similar impact of wall reflection & window transmissivity on non-visual potential.•The highest melanopic illuminance was more than twice the value of the lowest.
•Adaptive thermal comfort field study was conducted for subjects at a high metabolic rate.•About 92% and 68% students were found comfortable during autumn and winter season, respectively.•Accepted ...mean airspeed for male was higher than female (AVSm = 0.29 m/s; AVSf = 0.17 m/s)•Seasonal comfort temperature varied by more than 5°C.•Subjects are found to be more sensitive towards outdoor temperature fluctuations.
An adaptive thermal comfort study was carried for assessing the thermal comfort requirements of students working in naturally ventilated (NV) university workshop building in the composite climate of India over two seasons (Autumn and Winter). 1332 complete surveys, 516 and 816 from autumn and winter season, respectively were collected and analyzed. A maximum of 70% of subjects were found voting comfortable when indoor temperature varied from 28°C to 32°C. During the autumn season, the mean comfort temperature was about 5°C higher than the winter season. Also, female subjects had about 1.5°C higher comfort temperature compared to male subjects. Further, an attempt has been made to present an adaptive model for university students engaged in activity corresponding to machine work. The results were also compared with international thermal comfort standards. The results showed that students are more sensitive towards the fluctuations of outdoor conditions compared to the subjects in office and residential buildings. Moreover, subjects have shown better thermal adaptability towards prevailing mild cold climatic conditions through behavioural and clothing adjustments.
Climate change is expected to expose the locked-in overheating risk concerning bioclimatic buildings adapted to a specific past climate state. The study aims to find energy-efficient building designs ...which are most resilient to overheating and increased cooling energy demands that will result from ongoing climate change. Therefore, a comprehensive parametric study of various passive building design measures was implemented, simulating the energy use of each combination for a temperate climate of Ljubljana, Slovenia. The approach to overheating vulnerability assessment was devised and applied using the increase in cooling energy demand as a performance indicator. The results showed that a B1 heating energy efficiency class according to the Slovenian Energy Performance Certificate classification was the highest attainable using the selected passive design parameters, while the energy demand for heating is projected to decrease over time. In contrast, the energy use for cooling is in general projected to increase. Furthermore, it was found that, in building models with higher heating energy use, low overheating vulnerability is easier to achieve. However, in models with high heating energy efficiency, very high overheating vulnerability is not expected. Accordingly, buildings should be designed for current heating energy efficiency and low vulnerability to future overheating. The paper shows a novel approach to bioclimatic building design with global warming adaptation integrated into the design process. It delivers recommendations for the energy-efficient, robust bioclimatic design of residential buildings in the Central European context, which are intended to guide designers and policymakers towards a resilient and sustainable built environment.
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•Bioclimatic potential of locations in the Alpine-Adriatic region was analysed.•The analysis included precise consideration of solar irradiation influence.•Bioclimatic potential was ...compared with building’s energy performance analysis.•Cooling and heating energy demand coincided with bioclimatic potential prognosis.•Adequate correlation with Köppen-Geiger climatic classification was identified.
In recent years, the construction industry has been comprehensively focusing on energy performance of buildings and on achieving higher standards of living comfort. One of the most sophisticated ways to attain both at the same time is (re)achieving building’s climate balance by using bioclimatic design. Therefore, the main goal of this paper was to present a bioclimatic potential prognosis and to show its application on an example of the Alpine-Adriatic region. The bioclimatic potential prognosis was made for 21 characteristic locations. For this purpose, bioclimatic chart plots were made using elementary weather data and additionally, the actually received solar irradiance was precisely considered at every location. The latter was shown to have a large influence on the analysis results. Furthermore, an evaluation of performed bioclimatic potential prognosis was made with simulations of a generic building model using Energy Plus. The generic building model was tested in five selected locations and the heating and cooling demand results were compared with the bioclimatic potential analysis. The results showed that the application of the presented method can indicate which passive solutions should be applied in building design at a specific location in order to facilitate smaller energy usage and consequential higher indoor comfort. In addition, the presented approach can be used in order to incorporate the latest or predicted climate data into bioclimatic potential analysis. The latter has a significant influence on the design of buildings of the future.
•Thermal discomfort in a log house was assessed using a calibrated model.•Effective passive overheating prevention actions were identified for future climate.•Natural ventilation was the ...best-performing measure in reducing future overheating.•Building-related measures are of secondary importance under free-run operation.•Possibilities for future-proofing log houses are presented.
This study aimed to identify the most effective passive design measures to prevent overheating in a log house in a temperate climate. The study was conducted with a calibrated thermal model under a future climate projection (SRES A2 scenario) utilising an EN 16798–1 adaptive comfort model for the building operated under free-run mode during summer. The effects of six building-related and three organisational measures on the projected future thermal comfort in the studied log house were evaluated. During 2011–2040 and 2041–2070, thermal insulation and thermal mass paired with natural ventilation with or without shading were among the best-performing combinations. During 2071–2100, three of the six best-performing combinations were thermal insulation and thermal mass paired with natural ventilation with or without shading. Comparing the first and the last periods, the most effective organisational measure reduced the operative temperature by an average of 0.35 or 0.34 °C in the first two periods and by 0.36 or 0.33 °C in the third period. By outlining the potential effectiveness of specific measures in preventing overheating discomfort under climate change conditions, the findings significantly contribute to climate change adaptation of log houses and buildings in general. These findings can be used as design guidelines for future buildings and to formulate future building regulations as well as a decision-making support for policy-makers.
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