Passive Solar Research Articles

Evaluation of low-impact modular housing using energy optimization and life cycle analysis

This paper presents life cycle analysis of the container-based single-family housing and combines energy analysis and optimization, life cycle assessment and life cycle costing. The proposed models include the container code (CC), designed to Canadian national building code as reference model, and an improved container (IC) incorporating passive solar technologies. Utilizing passive design strategies results in approximately 79% reduction in annual operational energy consumption for the improved case. The life cycle assessment considers the total energy use and global warming potential over 60-year lifespan. Three life cycle phases are considered: pre-use, use and operation, and end of life. As a result of envelope upgrade, the IC offers 77% reduction in life cycle energy use and global warming potential (GWP) than the CC. However, the envelope upgrade requiring greater energy intensity through industrial processing of additional building materials led to higher environmental impact, approximately 65,370 kWh of embodied energy and 20 t of CO2 eq of GWP embodied carbon emissions for the improved container at pre-use phase. In terms of life cycle cost, IC shows less than 10% total cost savings as compared to CC. This study, however, proves that integrating passive solar design techniques in building not only results in reduced energy consumption but rather translates to reduction in life cycle environmental impacts and life cycle cost building systems, which is, in this case, a modular container housing.

Simulation and control of shading systems for glazed facades

This paper presents a simulation study on the use of shading devices in highly glazed facades in the context of zero emission buildings (ZEB) located in a Nordic climatic context. Shading devices have the task to control different uses of solar energy (solar gain for passive solar heating and daylighting) and to avoid cooling load, and to find the best strategy (i.e. to optimize the overall performance) for controlling shading devices is not trivial.Different control strategies for the activation of the shading devices (venetian blinds) are simulated, and their performance calculated in this study through a dynamic whole-building simulation tool (EnergyPlus). The results of the simulation studies show that it is possible to achieve very high performance and balanced use of solar energy (for passive solar heating, daylighting), without occurring in too high cooling load, even in the case of fully glazed facades. The optimal strategy for shading activation is not straightforward, and different strategies should be recommended during the year to assure an overall optimal performance.

Building’s solar chimney: The performance of width and inlet to in tropical country

The main purpose of the passive solar design strategy is to maximize the potential for abundance of solar radiation to improve the heating/cooling of buildings. One of them is by utilizing the stack ventilation strategy. Solar Chimney (SC) is a technology that utilizes this effect. Further simulation of Abraham’s research on buildings with SC such as widening the chimney and the opening/closing strategy of the inlet to test the performance of the inlet. The results showed that changes in the variation in width and angle of the solar chimney effectively increased the value of indoor wind speed by 10%. Whereas through the inlet open/close strategy it can be seen which inlet has the best performance.

Passive Solar Energy Utilization in Energy Efficient Building Design: Karataş Open Prison Textile Workshop Project

Bu çalışmada Karataş Kadın Açık Ceza Evi Tekstil atölyesi projesi tanıtılmaktadır. Yazar tarafından Haziran 2017 tarihinde Tekstil Atölyesi projesinin tasarımına başlanmış Aralık 2017’de tamamlanarak Karataş Kadın Açık Ceza İnfaz Kurumu Müdürlüğü’ne teslim edilmiştir. Çalışmada, projeye ilişkin tasarım süreci, tasarımda öne çıkan unsurlar, ergonomik faktörler, mekan kullanımları, alansal büyüklükler ve pasif tasarım ilkeleri ile elde edilen mekan kalitesi sunulmaya çalışılmıştır. 

Parametric synergy of passive design elements in cold-cloudy climate zones of north-east India

Boundaries of nations and states are not demarcated base on climate characteristics, but the generic application of design elements and materials in contiguous regions with antagonistic climates increase energy needs. Assam-type houses designed for warm-humid climate zones increases heating needs in cold-cloudy zones of North-East India. So, the intuitive and rational analysis of critical building elements parametric synergy is a prescient passive design. The method includes survey and analysis of climate and architectural thermal environment, parametric simulations, and synergy analysis. The studies show the evolution of similar design patterns in antagonistic climate zones. Simulation results shows that the integration of direct passive solar heat gain from moderate glazing area on South and West and indoor heat sources with moderate thermal mass heat storage and high envelope insulation are synergetic while the individual effects of only large glazing areas or only high thermal mass aren’t. The process for finding optimum parameters may be further iterated. Passive design entails intuitive architectural ingenuity base on climate and rational parametric synergy to straddle differences between climate and design elements to improve the design process and energy efficiency.

Coupling Effect of Space-Arrangement and Wall Thermal Resistance on Indoor Thermal Environment of Passive Solar Single-Family Building in Tibet

In areas where solar energy is abundant, such as the Tibetan plateau, passive solar buildings are attracting more and more attention and becoming a popular form of rural building. However, it is often difficult to achieve the satisfactory indoor thermal environment in a local rural passive solar single-family house. In order to improve the indoor thermal environment of passive solar buildings through building design, a systematic study of rural single-family buildings in Tibet was conducted. The basic parameters were investigated on the outdoor thermal environment, space-arrangement, envelope structure, and the indoor thermal environment. The building model considering space-arrangement modes was developed based on the survey data in multi-space passive solar buildings. The general physical and mathematical analysis models of multi-space passive solar buildings were established based on the heat transfer theory. Furthermore, the effects of space-arrangement and exterior wall thermal resistance on indoor air temperature were analyzed by numerical simulation. Results show that the indoor air temperature of the passive solar building is influenced by space-arrangement and wall thermal resistance together. When the space-arrangement of the building model was changed from “north-south through type” (mode a) to “through and separation combination” (mode b) and “north-south separation” (mode c), the indoor air temperature of the living room increased from 8.8 °C to 10.6 °C and 11.6 °C, with increases of 20.5% and 31.8%, respectively. In addition, equally increasing the thermal resistance of exterior walls in different orientations has different effects on the indoor air temperature. In the space-arrangement mode c, comparing with the temperature increment of the living room and bedroom caused by increasing thermal resistance of the south wall and north wall, the temperature increment of the living room caused by increasing thermal resistance of the east/west wall increased by 151.7% and 32.7%, and that of the bedroom increased by 609.1% and 239.1% respectively. This study can provide a reference for the optimal design of passive solar buildings in solar energy abundant areas.

Solar Strategies for net-zero energy housing in Canadian North

The North imports most of its energy for fuel and cost of fuel is much higher than the national average, consequently, cost for space heating relying on fuel is very high. The North has an abundance of solar energy available. With the growing concerns on climate change, the region desires to be less dependent on fossil fuels. Significant energy savings for little added cost in housing could be achieved by building high performing envelope systems and integrating solar design strategies. The objective of this paper is to investigate the potential of integrating solar design strategies in improving energy efficiency of housing suitable for the Canadian Northern climates through modelling by optimizing passive solar design and optimal use of thermal and electrical energy from Building Integrated Photovoltaic/Thermal system (BIPV/T) to achieve net-zero energy housing. A reference home with typical construction built in Northern region is modelled using EnergyPlus. The key solar design strategies and building envelope parameters are optimized to minimize energy consumption and maximize the energy production for the reference home. The parameters investigated include thermal resistance of building envelope components, window-wall ratios, thermal mass, night window shutters, shading schedules, and ventilation rates. The optimal use of thermal energy produced by BIPV/T system by integration with Heat Recovery Ventilation (HRV) and air-source Heat Pump (ASHP) is evaluated. Modelling results show that 43% energy saving can be achieved by optimizing the passive solar design and overheating can be eliminated by proper solar shading and natural ventilation. The integration of BIVP/T with HRV can reduce the frost cycle by 10.4%. These preliminary findings demonstrate the potential of integrating solar design strategies to reduce energy consumption and develop net-zero energy housing for the Canadian North.

My sustainable city — Exploring lay people’s conception of sustainable urban design

The new urbanism movement has repeatedly stressed the importance of dimensions such as density, land use and passive solar design in urban sustainability. However, little is known about lay people's conception of these constructs. If the urban environment is to be designed to prioritise people, understanding how they conceive of sustainability becomes important. The present study investigated lay people's conceptions of sustainable urban design by asking them to build their own cities with the urban simulation Sim City. In a balanced within-subjects design, participants were asked to create both the least and the most sustainable city they could imagine, whilst expressing their thought processes in a recorded think-aloud protocol. Transcripts were subsequently analysed for common themes which allowed for a comparison between participants' notions of sustainable urban design features and those identified by experts (Jabareen, 2006). This is the first time lay concepts of sustainability have been assessed this way. Participants showed awareness of several urban form factors including compactness, diversity, density, sustainable energy and transport, as well as greenery and mixed land use. The results further suggested that laypeople place particular emphasis on urban design aspects such as energy and transport. A key novel finding was that laypeople also include non-urban design aspects, such as education about the environment, in their notions of sustainability. These findings suggest there might be both mismatches and overlaps between expert and lay concepts of what a sustainable city entails, which in turn might help explain certain failures to engage with sustainable built environments.

Optimizing Building Envelope Dimensions for Passive Solar Houses in the Qinghai-Tibetan Region: Window to Wall Ratio and Depth of Sunspace

It has been a focus to reduce the energy consumption and improve the space heating performance of high-altitude buildings in winter seasons. In view of the abundant solar energy resources of the high-altitude region, the establishment of passive solar houses should be an effective strategy to deal with the problem of thermal comfort. Both window to wall ratio (WWR) and sunspace depth are of vital importance to determine the thermal comfort level of passive solar houses, while there are limited studies on analyzing their impacts on passive solar houses in high-altitude regions. Therefore, this study is designed to examine how WWR and sunspace depth affect space heating of passive solar houses in the Qinghai-Tibetan region. To be specific, the hourly radiation temperature variations and percentages of dissatisfaction of the residential building with different sunspace depth/WWR (including 0.9m/33%, 0.9m/45%, 0.9m/60%, 1.2m/33% and 1.5m/33%) were quantitatively examined. Results indicated that under the condition of 0.9m/45%, the overall average radiation temperature of the building was approximately 16°C during the entire heating season, which could better satisfy the heating requirements. Meanwhile, the average temperature was higher, and the thermal comfort level was better under the ratio of 45% or the depth of 1.5 m, when only an individual factor in either ratio or depth was considered. These findings can provide references for the determination of dimensions of passive solar houses in high-altitude regions.

BuildSense

Buildings can achieve energy-efficiency by using solar passive design, energy-efficient structures and materials, or by optimizing their operational energy use. In each of these areas, efficiency can be improved if the physical properties of the building along with its dynamic behavior can be captured using low-cost embedded sensor devices. This opens up a new challenge of installing and maintaining the sensor devices for different types of buildings. In this article, we propose BuildSense, a sensing framework for fine-grained, long-term monitoring of buildings using a mix of physical and virtual sensors. It not only reduces the deployment and management cost of sensors but can also guarantee accurate and fault-tolerant data coverage for long-term use. We evaluate BuildSense using sensor measurements from two rammed-earth houses that were custom-designed for a challenging hot-arid climate so almost no artificial heating or cooling is required. We demonstrate that BuildSense can significantly reduce the cost of permanent physical sensors while still achieving fit-for-purpose accuracy, fault-tolerance, and stability. Overall, we were able to reduce the cost of a building sensor network by 60% to 80% by replacing physical sensors with virtual ones while still maintaining accuracy of ≤1.0°C and fault-tolerance of two or more predictors per virtual sensor.

Life cycle assessment and life cycle costing of container-based single-family housing in Canada: A case study

This research presents an early-design analysis of single-family housing located in Calgary, Canada; and combines energy analysis, life cycle assessment (LCA), and life-cycle costing (LCC), to investigate the life cycle impacts associated with repurposing upcycled containers into modular housing. The study considers four case studies; container and lightwood designed to code specifications, both serving as base models and two improved models of container and lightwood, designed by incorporating energy efficiency measures and passive solar design standards.The life cycle assessment results for the code cases clearly show that majority of the life cycle environmental impacts (95%) occur at the use and operation phase, followed by the pre-use contributing 4%, and less than 1% at the end of life. For the improved cases, results show similar findings as the use and operation phase contributes approximately 85% impact, however, a higher pre-use impact of 12% is reported. Over the 50 years lifespan, the comparative life cycle impacts show only 3% difference when comparing container to lightwood cases.Sensitivity analysis show that utilizing Scenario 100:0 (container code-cut-of-method) in housing can result in a substantial amount of avoided impact about 46 (t CO2 eq) and (538 GJ) 149,444 kWh energy savings as compared to Scenario 0:100 (improved container – end of life recycling). Approximately 10% life cycle cost reduction is realized with the improved cases compared to code cases. This study proves the potentials for repurposing container for long-term usage as a building system, thereby meeting affordable housing needs with less environmental impacts.

Passive Solar Heating with Adjustable Heating Modes

This paper discusses different schemes of the performance of passive solar heating of buildings. Based on the solution for heat conduction equation for active building constructions taking into account the influence of convective heat transfer and heat flux, incoming solar radiation, the ways of energy-saving facilities’ operation is analyzed. It is shown that to increase the efficiency of such systems, an individual design should be performed taking into account the climatic features of the construction area, and the choice of rational combinatorics for the outer shell, such as movable shielding heat-protective device, and creating an air gap between the accumulating and heat-insulating layers. Based on the calculations, the energyactive area of the bearing course of buildings, protected from the outer side with the translucent barrier is revealed. The suitable thickness of the accumulation layer for recycling process of solar radiation is determined. The presented innovative technical solutions could help to enhance the efficiency of solar energy utilization and contribute to more active implementation of passive solar heating, expanding the scope of their territorial application

Passive Solar design basics, a way for low emission buildings?

Danish Building Regulation allows a market that chooses non-compact and non-passive Solar optimized design. This leads to balance higher heat demand with surplus active solar gains in calculating a yearly energy balance. Expectations like „Soon we will have district heating with CO2 neutral biomass and batteries to save so is there a need for solar passive design?” further encourages to assume, that summer solar gains might be saved for winter heating demand in a not so far future. As a passive house architect, I am often confronted with this question and this way of thinking by politicians and architecture students. They do care about climate change, but do not seem to understand why we ought to change the way we plan building space and energy systems. The contribution architects can make to reduce climate impact by building spaces that ensure a passive exploit of the suns energy, not just surfaces to mount active solar devices, is not commonly understood.

Passive solar design for energy efficiency in buildings in composite climate

Renewable energy sources offer an unlimited supply of energy. Solar energy can be utilized to supplement energy needs of a building either passively or actively. It is feasible to reduce consumption of energy usage for heating, cooling and lighting requirements of a building by adopting a climate sensitive approach for design of building elements like static sunshade, wall and roof. To study the effect of passive building elements in composite climate zone, four rooms were designed with a different combination of type of static sunshade, wall and roof. The static sunshade and brick cavity wall with brick projections were designed using sunpath diagram and shadow angles. Air cavity was introduced in the reinforced cement concrete (RCC) roof by laying hollow stoneware pipes. This paper presents theoretical and simulation studies to compare thermal performance of the four rooms. Theoretically, the four rooms were compared by steady state method based on total heat load in every month and on representative days in different seasons throughout the year. The extreme and most frequently occurring temperature values (mode) in every season were identified by obtaining the frequency distribution of the outdoor air temperature with the software SPSS Statistics (IBM Corp. 2012). Results showed that room with designed passive elements gained minimum heat in summer and moderate summer, while it lost minimum heat in winter and moderate winter. This shows the effectiveness of the designed passive elements in insulating the room interiors from the extreme climatic conditions. The rooms were also simulated using software Autodesk Ecotect Analysis 2011 and their performance was compared on a typical day in each month. Results showed that this software can be helpful for preliminary design to get an idea about the room performance that can help to create thermally comfortable indoor environment for the well being of occupants.

Heating canarian greenhouse with a passive solar water–sleeve system: Effect on microclimate and tomato crop yield

Heating greenhouses is indispensable for plant development particularly in winter when air temperature is lower. In that sense, passive solar heating is a promising alternative compared to classic methods such as fossil fuels that are cost impacted and harmful to the environment.The current work is devoted to the study of the effect of a solar heating system using black plastic sleeves filled with water on the microclimate, tomato yield and the dynamic population of the tomato key pest, Tuta absoluta (Lepidoptera: Gelechiidae) in canarian greenhouses.The results show that the use of this heating system, improves the nighttime temperature inside the greenhouse by 3.1 °C and reduce by 10% the relative humidity compared to the control greenhouse. This microclimate improvement has a positive impact on the tomato production. It has increased by 35% compared to the control greenhouse. It was also noted that the presence of this heating system lead to a decrease in the development the population of T. absoluta in the heated greenhouse.Based on these results, the solar passive water–sleeve heating system can be an eco-friendly tool to prevent intensive use of fuel fossil and negative effect on the environment.

Numerical analysis of the thermal behavior of building integrated hybrid solar wall

Abstract Building designers have to think about new strategies to achieve the best sustainable building designs. Well-planned passive solar heating strategies in building design may reduce a building’s energy consumption significantly. In this paper, a proposed design of the south façade of a room by integrating a hybrid solar wall and a window to passively heat a room is studied. The simulations for the three-dimensional model of BIPV Trombe wall system were carried out for December 10th, 2015. The temperature and velocity distribution of indoor air in different positions inside the room are obtained from the simulation results. The obtained results show that the temperature difference between the inlet and the outlet of the solar wall can reach 9°C. The 3D analysis of the proposed model clearly shows that the window’s thermal effect on the passive heating cannot be neglected. Meanwhile, the simulation’s daily electrical efficiency conversion and average indoor air temperature of this system can reach 18% and 28° C, respectively for maximum solar radiation of 470 W/m2.

Research Status and Development Trend of Solar Heating Technology

As one of the renewable green energy sources, solar energy has great advantages in energy conservation and environmental protection. With the deepening of the research on solar heating technology, more issues have been discussed. This paper summarizes the research status of solar heating technology from two aspects of solar energy heat collection and heating implementation. Firstly, heat collection technology is still the key to solar energy heat utilization, which focuses on the numerical simulation of heat collector and the influence of heat collection structure on heat collection capacity. Secondly, thermodynamic analysis of heat transfer enhancement of ventilation gap and air flow in passive solar heating system is a hot topic; some scholars even put forward new heat transfer theoretical models and improved equations. Whereas in the active solar heating system, due to the imbalance and instability of solar energy, most of the research focuses on the construction of multiple complementary heating system and the corresponding optimal operation mechanism as well as the study of solar energy heat storage materials, devices and their heat storage performance. Thirdly, in view of the actual building environment in rural areas of northern China, it is proposed that using distributed solar energy collection method combined with heat storage technology and using green energy internet to distribute heat energy is the research trend of maximizing the application of solar heating in the region.

Numerical analysis on the thermal performance of a novel PCM-encapsulated porous heat storage Trombe-wall system

Phase change material (PCM) applied in the architectural equipment can decrease building energy consumption and ameliorate thermal comfort by heightening its thermal energy storage capacity, and it has been a research hotspot in recent years. For the purpose of saving building energy in a simple and effective way, a novel solar composite wall with a porous heat storage layer in the present paper, and its matrix consists of the PCM encapsulated granular capsules, so the phase change occurs in the encapsulated capsules when the temperature reaches the melting point. The unsteady numerical simulation is conducted to analyze the performance of passive solar heating room. In the daytime, a large amount of heat can be stored in the porous layer due to the occurrence of phase change in the capsules, once the temperature of porous layer is above a certain value. The heat can be released at night or in a cloudy day when the temperature is below the solidification temperature, thus, the overheating can be avoided in the room and the heat can be fully utilized. The comparisons are conducted between the porous layer with and without PCM encapsulated granular capsules in the composite wall for heating. And in comparison with the granular capsules-consisted porous layer which without PCM, approximate 20.2% increment of average temperature at night can be achieved in the heating room when the PCM is packaged in the porous layer. The thermal efficiency of the PCM heat storage wall is 76.2%. Besides, the structure parameters and combined modes in the porous composite solar wall are analyzed. For instance, the porous storage wall with a porosity of 0.1 and a thickness of 6 cm are reasonable choices in this model.

Optimization of HVAC system energy consumption in a building using artificial neural network and multi-objective genetic algorithm

The optimization of heating, ventilating and air conditioning (HVAC) system operations and other building parameters intended to minimize annual energy consumption and maximize the thermal comfort is presented in this paper. The combination of artificial neural network (ANN) and multi-objective genetic algorithm (MOGA) is applied to optimize the two-chiller system operation in a building. The HVAC system installed in the building integrates radiant cooling system, variable air volume (VAV) chiller system, and dedicated outdoor air system (DOAS). Several parameters including thermostat setting, passive solar design, and chiller operation control are considered as decision variables. Subsequently, the percentage of people dissatisfied (PPD) and annual building energy consumption is chosen as objective functions. Multi-objective optimization is employed to optimize the system with two objective functions. As the result, ANN performed a good correlation between decision variables and the objective function. Moreover, MOGA successfully provides several alternative possible design variables to achieve optimum system in terms of thermal comfort and annual energy consumption. In conclusion, the optimization that considers two objectives shows the best result regarding thermal comfort and energy consumption compared to base case design.

Heating performance enhancement of a new design trombe wall using rectangular thermal fin arrays: An experimental approach

Abstract It has been nowadays recognized that addressing energy use in buildings can reduce the fossil fuels usage and CO2 emission. Trombe wall is a widely applicable passive solar design option that can significantly reduce the fossil fuel consumption in buildings. This paper experimentally dealt with the effect of applying vertical thermal fin on the absorber of Trombe wall with new design. Three types of aluminum, brass and copper fins were investigated. The experiments were carried out at arid climate of Yazd, Iran. The results showed that when the thermal fin is used the performance efficiency of the Trombe wall increases up to 3% in terms of stored energy within the Trombe wall and 6% in terms of natural convection heat transfer rate inside the channel. However, adopting more thermal fins on the absorber could not ensure higher heating efficiency in terms of stored energy for all cases. Furthermore, copper fin led to maximum heating efficiency and highest average room temperature among three fin types.