Passive intelligent kinetic external Dynamic shade design for improving indoor comfort and minimizing energy consumption

In humid subtropical climates with a green environment, windows are the most dominant envelope elements affecting indoor visual and thermal comfort and visual connection to the outdoors. This research aims to optimize a dynamic external shading system for north-facing windows in Sydney, Australia, which acts automatically in eight predefined scenarios in response to indoor comfort conditions. The method of investigation was simulating a multi-objective optimization approach using Non-dominated Sorting Particle Swarm Optimization (NSPSO) to assess visual and thermal comfort along with energy usage and view of the outside. A combination of human and sensor assessments were applied to validate the simulations. A set of sensors and High Quality (HQ) cameras fed the system input to operate the shade. Simulations and field measurements demonstrated that optimized shading scenarios brought average yearly reductions of 71.43%, 72.52%, and 1.78% in Annual Solar Exposure, Spatial Daylight Glare, and LEED Quality View, respectively, without sacrificing Daylight Autonomy. Moreover, yearly improvements of 71.77% in cooling demand were achieved. The downside of the shading system was an increase of 0.80% in heating load and 23.76% in lighting electricity, which could be a trade-off for improved comfort and energy savings. This study investigated the effect of dynamic external shade on visual and thermal comfort together with energy usage and view, which has not been investigated for southern-hemisphere dwellings. A camera-sensor-fed mechanism operated the external shade automatically, providing indoor comfort without manual operation

Curve optimization for the anidolic daylight system counterbalancing energy saving, indoor visual and thermal comfort for Sydney dwellings

Daylight penetration significantly affects building thermal-daylighting performance, and serve a dual function of permitting sunlight and creating a pleasant indoor environment. More recent attention has focused on the provision of daylight in the rear part of indoor spaces in designing sustainable buildings. Passive Anidolic Daylighting Systems (ADS) are effective tools for daylight collection and redistribution of sunlight towards the back of the room. As affordable and low-maintenance systems, they can provide indoor daylight and alleviate the problem of daylight over-provision near the window and under-provision in the rear part of the room. Much of the current literature on the ADS pays particular attention to visual comfort and rarely to thermal comfort. Therefore, a reasonable compromise between visual and thermal comfort as well as energy consumption becomes the main issue for energy-optimized aperture design in the tropics and subtropics, in cities such as Sydney, Australia. The objective of the current study was to devise a system that could act as a double-performance of shade and reflective tool. The central aim of this paper is to find the optimum curve that can optimize daylight admission without an expensive active tracking system. A combination of in-detail simulation (considering every possible sky condition throughout a year) and multi-objective optimization (considering indoor visual and thermal comfort as well as the view to the outside), which was validated by field measurement, resulted in the optimum ADS for the local dwellings in Sydney, Australia. An approximate 62% increase in Daylight Factor, 5% decrease in yearly average heating load, 17% savings in annual artificial lighting energy, and 30% decrease in Predicted Percentage Dissatisfied (PPD) were achieved through optimizing the ADS curve

Thermal Comfort Performance of Wind Towers in the Australian Residential Context

This study investigates the performance of a wind tower in contemporary medium-density residential structures in subtropical Sydney, Australia. Wind towers have been a traditional residential and commercial natural ventilation system for more than three thousand years in Persia and neighbouring countries. Wind-induced ventilation offsets solar gain by cooling the building structure and improving occupant comfort in warm to hot weather by increasing indoor air movement. As Australian metropolitan cities increasingly tend towards medium-density apartment-style housing, urban canyons are created where pollution and noise result in a heavy dependence on air conditioning behind sealed windows. Concerns about climate change and global warming also support the introduction of a natural ventilation system to provide occupant comfort and reduce cooling load. This four-phase study evaluates wind tower natural ventilation using wind-driven indoor air movement for occupant comfort. First, a sealed scale model of a typical residential apartment incorporating a wind tower was tested within a boundary layer wind tunnel under three urban context scenarios, assessing the effects of windward obstructions on the external pressure distribution over the building model and the associated wind tower. A large number of internal and external geometrical configurations of wind tower were analysed leading to an optimised wind tower design. In the second phase, this design was exposed to Sydney’s contemporary meteorological data to assess its applicability in the Sydney climate. The third phase of study quantified comfort performance of a wind tower for the six warmest months of the year. In the fourth phase, the cumulative total improvement in indoor comfort temperatures was applied in an energy calculation procedure to predict the potential of wind tower ventilation to reduce electricity demand and carbon emission. The results indicated that, in ambient temperatures of 23°C and above, the optimised wind tower in the most conservative scenario increased indoor air speeds at average 0.4 m/s and improved indoor comfort by 4935 degree hours (ΣΔSET*) compared to the default design relying on through-window ventilation. The wind tower produced an average cooling potential (ΔSET*) of 3°C and decreased cooling loads by 25 kWh/m2/y

Strategies and scenarios to reduce energy consumption and CO2 emission in the urban, rural and sustainable neighbourhoods

peer reviewedThe building sector has become a major source of worldwide carbon emissions and energy consumption because of rapid population growth and a continuous environmental strain caused by humanity. A lack of consistent data on life-cycle carbon emissions and energy demand at the neighbourhood level has made it difficult to understand the origins of climate change at this scale. A sensitivity analysis brought clarity concerning the extent of environmental impacts on future climate evolution. From this perspective, the authors aimed to evaluate, analyse, compare, and provide recommendations to reduce carbon emissions, as well as the energy required by three types of neighbourhoods (urban, rural, and sustainable) located in and adapted to all countries worldwide. The most important parameters affecting carbon emission and energy consumption were analysed, including the energy mix of countries, local building materials and climate, technological solutions utilised, daily mobility, and occupied spaces. The results indicated that the highest levels of carbon dioxide emissions were produced by countries with prosperous economies, such as China, the United States, India, Germany, and Poland, because of high concentrations of coal in their energy mixes. Modernising cities through the construction of new ecodistricts and increasing the use of new techniques for substantial renovations of outdated buildings worldwide could mitigate the amount of greenhouse gases emitted by neighbourhoods 53–97 % by 2050. Moreover, by combining substantial building renovations with the installation of photovoltaic panels on roofs, the objective of ‘zero carbon’ at the neighbourhood level could be achievable by 2050 in rural neighbourhoods. Radical changes in the judicious choice of construction materials and use of green energy production represent targeted opportunities to resolve the future climate dilemma

Passive Intelligent Kinetic External Dynamic Shade Design for Improving Indoor Comfort and Minimizing Energy Consumption

In humid subtropical climates with a green environment, windows are the most dominant envelope elements affecting indoor visual and thermal comfort and visual connection to the outdoors. This research aims to optimize a dynamic external shading system for north-facing windows in Sydney, Australia, which acts automatically in eight predefined scenarios in response to indoor comfort conditions. The method of investigation was simulating a multi-objective optimization approach using Non-dominated Sorting Particle Swarm Optimization (NSPSO) to assess visual and thermal comfort along with energy usage and view of the outside. A combination of human and sensor assessments were applied to validate the simulations. A set of sensors and High Quality (HQ) cameras fed the system input to operate the shade. Simulations and field measurements demonstrated that optimized shading scenarios brought average yearly reductions of 71.43%, 72.52%, and 1.78% in Annual Solar Exposure, Spatial Daylight Glare, and LEED Quality View, respectively, without sacrificing Daylight Autonomy. Moreover, yearly improvements of 71.77% in cooling demand were achieved. The downside of the shading system was an increase of 0.80% in heating load and 23.76% in lighting electricity, which could be a trade-off for improved comfort and energy savings. This study investigated the effect of dynamic external shade on visual and thermal comfort together with energy usage and view, which has not been investigated for southern-hemisphere dwellings. A camera-sensor-fed mechanism operated the external shade automatically, providing indoor comfort without manual operation

Ambient Air Pollution and Stillbirths Risk in Sydney, Australia

We aimed to determine the associations between ambient air pollution, specifically particulate matter less than or equal to 10 microns and 2.5 microns (PM10 and PM2.5 respectively) and ozone (O3), and stillbirths. We analysed all singleton births between 20–42 weeks gestation in metropolitan Sydney, Australia, from 1997 to 2012. We implemented logistic regression to assess the associations between air pollutants and stillbirth for each trimester and for the entire pregnancy. Over the study period, there were 967,694 live births and 4287 stillbirths. Mean levels of PM10, PM2.5 and O3 for the entire pregnancy were 17.9 µg/m3, 7.1 µg/m3 and 3.2 ppb, respectively. Adjusted odds ratios were generally greater than unity for associations between PM and stillbirths, but none were statistically significant. There were no significant associations between O3 and stillbirths. There was potential effect modification of the PM10 and O3 association by maternal age. We did not find consistent evidence of associations between PM and O3 and stillbirths in Sydney, Australia. More high quality birth cohort studies are required to clarify associations between air pollution and stillbirths

Curve Optimization for the Anidolic Daylight System Counterbalancing Energy Saving, Indoor Visual and Thermal Comfort for Sydney Dwellings

Daylight penetration significantly affects building thermal-daylighting performance, and serve a dual function of permitting sunlight and creating a pleasant indoor environment. More recent attention has focused on the provision of daylight in the rear part of indoor spaces in designing sustainable buildings. Passive Anidolic Daylighting Systems (ADS) are effective tools for daylight collection and redistribution of sunlight towards the back of the room. As affordable and low-maintenance systems, they can provide indoor daylight and alleviate the problem of daylight over-provision near the window and under-provision in the rear part of the room. Much of the current literature on the ADS pays particular attention to visual comfort and rarely to thermal comfort. Therefore, a reasonable compromise between visual and thermal comfort as well as energy consumption becomes the main issue for energy-optimized aperture design in the tropics and subtropics, in cities such as Sydney, Australia. The objective of the current study was to devise a system that could act as a double-performance of shade and reflective tool. The central aim of this paper is to find the optimum curve that can optimize daylight admission without an expensive active tracking system. A combination of in-detail simulation (considering every possible sky condition throughout a year) and multi-objective optimization (considering indoor visual and thermal comfort as well as the view to the outside), which was validated by field measurement, resulted in the optimum ADS for the local dwellings in Sydney, Australia. An approximate 62% increase in Daylight Factor, 5% decrease in yearly average heating load, 17% savings in annual artificial lighting energy, and 30% decrease in Predicted Percentage Dissatisfied (PPD) were achieved through optimizing the ADS curve

Recent Climatic Trends and Analysis of Monthly Heating and Cooling Degree Hours in Sydney

Recent climatic trends of two nearby stations in Sydney were examined in terms of hourly ambient air temperature and wind direction for the time period 1999-2019. A reference was set for the monthly number of cooling (CDH) and heating (HDH) degree hours and the number of monthly hours that temperatures exceeded 24 degrees C (T24) or were below 14 degrees C (T14), parameters affecting not only the energy demands but also the quality of life. The degree hours were linked to the dominant synoptic conditions and the local phenomena: sea breeze and inland winds. The results indicated that both areas had higher mean monthly number of HDH (980-1421) than CDH (397-748), thus higher heating demands. The results also showed a higher mean monthly number of T14 (34-471) than T24 (40-320). A complete spatiotemporal profile of the climatic variations was given through the analysis of their dynamic progress and correlation. In order to estimate the daily values of CDH and HDH, T24 and T14 empirical models were calculated per month based on the maximum and minimum daily air temperatures. The use of forecasted weather conditions and the created empirical models may later be used in the energy planning scenarios

Comfort cooling by wind towers in the Australian residential context : experimental wind tunnel study of comfort

Comfort performance of a wind tower in a residential setting was evaluated in a series of wind tunnel experiments using a sealed, four storey apartment building model at 1:100 scale. This study was structured into three phases; first, the pressure distribution over the wind tower openings and the building fenestrations were measured in a boundary layer wind tunnel. From these data, internal bulk flow air change rates and mean indoor room air speeds were derived. Second, the pressure coefficient results of the first phase were applied to the Sydney Typical Meteorological Year (TMY) to assess the ventilation performance of the wind tower in terms of hourly indoor air speed. Wind tower results were benchmarked against through-window cross ventilation. In the third phase, increased indoor air speeds under wind tower ventilation were processed through the Standard Effective Temperature (SET*) comfort model to compute the additional comfort degree hours resulting from inclusion of a wind tower. Results indicate that the wind tower reduced indoor SET* values by an average 3.2 ​°C relative to conventional through-window cross-ventilation during Sydney's summer when outdoor temperatures were warmer than neutral