Passive Solar Research Articles

Application of heat pump assisted solar evacuated tube water heater operated within passive solar house in severe cold region

Replace coal with solar energy to low-cost heating in severe cold regions can improve indoor air quality, but indoor thermal comfort is not fully guaranteed. Therefore, a dual-source heat pump (DSHP) assisted solar evacuated tube water heater heating system was used in a house with sunspace to meet the heating stable and cleaning. TRNSYS model verified by experiment was used to research performance and economy of system. Results found the higher ambient temperature and solar radiation, the more heat from sunspace, solar assisted heat pump (SAHP) and solar water heater, conversely, the longer heating time of air-source heat pump (ASHP). During heating season, solar fraction of heating was 51.6 %, solar heat collection efficiency was 46.0 %, EER was 3.35, COP were 2.81 (ASHP) and 3.65 (SAHP). Heating time proportion of ASHP, SAHP and solar water heating were 15.0 %, 40.3 %, 44.7 %, ASHP heating was accounting for 22 % and 50 % in November and January. The system, sunspace supplied 16707.1, 2307.6 kW h of heat for room, solar effective heat collection was 10107.0 kW h, power consumption was 5164.7 kW h, CO2 emission reduction was 14232.4 kg. The dynamic payback period of system was 6.78 years, as will be shortened with support of clean energy heating policy.

An Overview of the Effects of Passive Solar Strategies on Thermal Comfort

The paper presents the impact of passive solar strategies on residential buildings concerning the thermal comfort factor. This study focuses on passive solar design elements like orientation, shading, and thermal mass to offer improved energy efficiency and occupant comfort. With a global natural gas crisis looming, interest in alternative heating and cooling is surging. With the growing concern of reducing the energy use by buildings while maintaining proper thermal comfort, both in cold and hot climates, the interest shifts to passive solar strategies. In this view, 547 publications have been analysed to reveal knowledge gaps and trends in the research. The bibliographic and thematic analysis techniques identified some approaches to passive solar design but no dominant method. Further, the study found under-researched areas within themes that appeared established. The authors have finally concluded with calls for further research and collaboration across institutions and nations to address these gaps and develop effective passive solar strategies. These findings contribute to sustainable architecture by pointing out the pros of applying passive solar strategies to reduce heating and cooling loads. In this respect, this was an original approach since it brought both quantitative and qualitative data together to measure thermal comfort. This is further underpinned by raising the need for energy-efficient building designs as measures toward mitigating climate change impacts.

CFD analysis of the impact of air gap width on Trombe wall performance

AbstractIn recent years, there has been a lot of research and debate on how solar energy can be used instead of conventional sources of heating to power residential heating. In this study, the Trombe wall (TW) technique, based on natural convection and energy storage, was examined to predict mass flow rate, temperature field, and velocity field for the TW system under steady conditions. A numerical simulation model was investigated for further validation using k‐ε turbulence and discrete ordinates (DO) radiation models. Independent grid studies were conducted to ensure that there were no changes after varying the grid numbers. The effect of the air gap was carried out to enhance TW thermal performance. CFD simulation shows good agreement with published data in the literature, and the optimum air gap was set at 0.1 m. The results pave the way for future studies to improve passive solar heating systems, which will eventually help move towards more sustainable residential heating solutions.

Green building and energy efficient design

In the construction industry, adopting strategies such as energy-efficient design or construction as well as green building construction technologies will minimize environmental harm and promote sustainability. The energy efficiency is emphasized as a core part of sustainability within the architecture, also as the perceiving ‘what is…’, its methods and benefits, green building concepts are explored. It includes energy efficiency, water efficiency, materials efficiency, interior environmental quality and site and building design efficiency. There is mention of a range of energy efficiency measures including the use of advanced insulation systems, passive solar design, energy management techniques, and the use of renewable energy sources. All these points bear very clearly the projections for enhancement of urban landscapes and health of the world while also looking into the challenges and possibilities for the future of the green building practices.

Study of a Novel 3D Façade Configuration and Its Impact on Energy Performance and Office Space Sustainability

This research paper examines how multi-angled façade systems improve and optimise energy performance compared to a flat façade and meet sustainability targets for lower energy use to align with UN SDGs 3, 11, 12, and 13. The multi-angled façade system does not tilt up and down. Instead, it employs two different window orientations on a vertical axis (left and right). The large portion orients more to the north to allow more daylight to penetrate inside the room, and the small part is oriented more to the south to provide passive solar heating. The investigations in this research paper were carried out using version 4.8 of the IDA ICE software, and the researchers evaluated the energy consumption, the energy action through the façade, and the building’s inside operative temperature. The results of this paper present the simulation findings for primary energy consumption in different scenarios. For example, the researchers explain that one can save 6.3 kWh/(m2·year) when using a multi-angled façade system compared to a flat façade. This is in addition to improving the thermal indoor climate that results from using the façades. The conclusions of the research show that the façade with multiple angles maximises using daylight and optimises solar power, thus avoiding overheating issues.

Optimizing Building Orientation for Passive Cooling

This research paper explores the application of passive design strategies in three museums in Lagos, Nigeria: The National Museum, Jaekel House, and the Heritage Museum in Badagry. The study focuses on building orientation as a key passive design strategy and evaluates its effectiveness in enhancing energy efficiency and thermal comfort in tropical climates. With the use of data collection from Google Earth Pro, a comparative analysis examines the architectural features and design elements of each museum, highlighting their use of building orientation, shading devices, and landscaping to optimize passive cooling and natural lighting. The innovative layout and strategic orientation of the National Museum demonstrate a successful integration of passive design strategies, while Jaekel House's use of deep overhangs and vegetation showcases a deliberate commitment to sustainable architecture. The Heritage Museum in Badagry, with its historical significance, presents an intriguing case study for passive design. While limited information is available, satellite imagery suggests an optimal orientation for passive solar design, complemented by deep overhangs and a reflective roof. The findings suggest that the three museums can benefit from further enhancements to their passive design strategies, including the integration of renewable energy sources, smart building systems, green roof systems, and water harvesting and management systems. In addition, educational initiatives can raise awareness and promote sustainable practices among visitors and the local community.

Innovative methods to optimize the integration of passive solar design principles into buildings

Innovative methods to optimize the integration of passive solar design principles into buildings

Prediction research on the contribution degree of solar energy to the coefficient of heating performance of carbon dioxide heat pump

The carbon dioxide heat pump (CDHP) offers efficient heating over a wide temperature range, but its heating energy efficiency under low-temperature conditions decreases obviously due to a correlation with the evaporation temperature, limiting the widespread use of CDHP in cold regions. To address this, we implemented a passive solar house with short-term heat storage capacity to raise the evaporation temperature and studied it by experimental and theoretical analysis. We introduced the concept of contribution degree (K) of solar energy to the heating performance coefficient of CDHP. The prediction models for the evaporation temperature, heating performance coefficient, and K were constructed gradually. The study optimized the operation mode of solar-assisted CDHP using the evaporation temperature partition theory and presented a method to calculate the limit distribution range of K. The result shows that the order of importance level of the significant items on evaporation temperature was ambient temperature (Ta) > direct solar irradiance on the inclined surface (Gb) > scattering solar irradiance on the inclined surface (Gr) > GḃTa > Ta2 > Gb2. The predicted limit distribution range of K was [0.00, 8.17]. The study optimized the operation mode of solar-assisted CDHP into three categories. It was observed that K changes positively with any single variable according to the law of a composite function composed of a natural exponential function and a quadratic function. Our study suggests a feasible development direction and offers a new theoretical and engineering basis for overcoming the large-scale application limitations of CDHP in cold regions.

Building Mass Optimization to Reduce Solar Radiation in High Rise Building by Using Parametric Approach

Buildings use 40% of global primary energy, therefore their design and use affect climate change. Building performance analysis can assist architects predict performance before construction with parametric design tools. Radiance can be reduced via a parametric mass, lowering cooling load and energy use. The study uses theoretical and computational research to explain, forecast, and analyze events, whereas parametric design optimizes complicated geometries using mathematical parameters and algorithms. Environmental analysis in Grasshopper with the Ladybug plugin uses Rhinoceros. This plugin provides solar radiation, and climate analysis capabilities. To determine the most energy-efficient building design, the research links independent and dependent variables such solar radiation intensity and building mass. The study uses Surabaya weather data and high rise buildings. The land is formed like a square, with a 15-degree slope to the north and is flanked by low-rise buildings. As a result, the location receives the most direct sunlight during the day. Then, solar radiation analysis. It helps optimize passive solar design solutions. According to the modelling results, solar radiation on the top and west sides are particularly large and dominant in 65.37 and 32.69 kWh/m2. Meanwhile, the north, east and south sides receive very little solar radiation. The following simulation considers the optimal direction, which is to extend west-east and face to the south. A multi-towered megastructure is a high-rise building that responds best to solar radiation. The total solar radiation value is 3,718,100 kWh. It can accommodate large spaces with large mass composition but relatively low total solar radiation values. The building towers provide shade to each other, thereby reducing direct radiation from the sun to the building. The sides of the building's podium are also shaded, so the top of the building is partially red.

Advancing Sustainability: Paper for Enhancing Eco-Friendly Methodology in the Shanghai Tower

This proposal aims to enhance the eco-friendly methods of the Shanghai Tower, a prominent building in Shanghai, by implementing additional sustainable practices. The building already incorporates various environmental friendly technologies, such as vertical green vegetation, intelligent building skin, natural ventilation, passive solar heating, and more. This proposal suggests further enhancements, including optimization natural lighting, rainwater collection, ice-need cold technology, on-site renewable energy utilization, and intelligent control systems. By implementing these measures, the Shanghai Tower can emerge as a pioneering model for other buildings, making significant contributions to environmental preservation, energy efficiency, and sustainable development in the region.

Impact of operation strategies on performance of integrated kang-floor heating system in severe cold areas

Efficiently and cost-effectively meeting the heating requirements of residents in severely cold regions by utilizing solar energy is currently a pressing need. Therefore, a solar heating system that integrated Kang-floor heating was established and tested for a passive solar house in Gan-nan Tibetan. This study reveals the effects of adjusting the flow/intermittent time periods and implementing variable flow rate operations on performance of system, to improve energy efficiency and optimize sleeping comfort. Findings indicated decreasing flow/intermittent time to 15/15 min had strengthened the average heat transfer from the water side, and mitigated the influence of returning water on internal water temperature of the tank, ultimately enhancing heat supply. The heating period was divided into three stage (18–24, 0–4, 4–8 o'clock), with a specific flow rate assigned to each stage. Under five flow rate configurations(A-E) with identical initial conditions: during constant flow rate, the greater the initial supply water temperature of the system, the more heat was transferred to room, and the higher heating efficiency was achieved, however, under variable flow rate, the effect of the water temperature on heating efficiency was significantly less evident. Mode B (low-to-high flow rate) had the highest heating efficiency and heat supply. The heating rate and cooling rate of Kang surface, temperature variations were notably less compared to the other four modes. Shortening the flow/intermittent periods and implementing variable flow method could improve the system's heat supply and sleep comfort with limited capital and resource investment.

Thermal performance of a novel Trombe wall enhanced by a solar energy focusing approach

The Trombe wall is a passive solar building exterior wall system proposed by Professor Felix Trombe in France, which can collect solar energy to heat buildings without additional energy consumption, making it a focal point of research in building energy conservation. However, its effectiveness is constrained by the low density of solar radiation in winter and the potential for overheating in summer. This study introduces a novel Trombe wall designed to address these issues through a focused strategy, enabling automatic transition between heating during winter and shading during summer. The thermal performance parameters of the novel Trombe walls in both winter and summer seasons are examined, and their energy consumption is assessed using experimental research methodologies. Findings indicate that the novel Trombe wall facilitates greater energy savings in both winter and summer. When compared with traditional Trombe walls, the novel Trombe wall achieves a significant reduction in energy consumption, with up to 55 W/m2 in heating load during winter and 47 W/m2 in cooling load during summer. The introduction of this new system holds substantial potential for the realization of zero-energy buildings.

Preparation and investigation of a prefabricated salt hydrate phase change material partition for passive solar buildings

The incorporation of phase change material (PCM) into building structures offers a pathway for passive energy storage, enabling adaptable indoor temperature control and alleviating energy consumption. Despite these advantages, the widespread adoption of PCM in building structures faces challenges due to extended payback periods. In this study, a novel and cost-effective salt hydrate PCM composite, comprised of calcium chloride hexahydrate–potassium chloride (CCH–KCl), was developed. Melamine foam (MF) and strontium chloride hexahydrate (SCH) were synergistically utilized to address phase separation and supercooling issues. Numerical simulations were conducted to assess the performance of the developed salt hydrate PCM composite in building partition walls. Specifically, incorporating a 20 mm-thick composite resulted in peak temperature reductions of 0.72 °C during normal operation and 1.01 °C during power outages compared to structures without PCM, accompanied by a substantial reduction in energy consumption by 5376.68 kWh/year. Moreover, the cost of the developed salt hydrate PCM is 89.33 % lower than industrial paraffin, and it reduces CO2 emissions by 1.40 kg/year/m2 compared to paraffin's 1.11 kg/year/m2. In summary, the developed salt hydrate PCM composite exhibits commendable thermal regulation and economic advantages in building applications, serving as a pivotal contributor to emission reduction efforts.

Architectural Design Recommendations Based on Bioclimatic Features Using Climate Consultant and Mahony Tables Strategies

Abstract The aim of this research is to provide bioclimatic design suggestions to improve the thermal comfort of people in hot and humid climates according to the BWh (hot desert climate) Köppen climate classification. The city of Minia is considered one of Egypt’s hot desert regions. This study considered two main variables to achieve thermal comfort according to air velocity and temperature. To select the best bioclimatic design tactic, the findings are reviewed and plotted on the Climate Consultant (CC) Bioclimatic Chart and the Mahoney Table (MT). The proposed procedures are presented as figures relating to the approaches and are examined independently. We conclude that specific bioclimatic design strategies have been applied through the extensive study presented in this paper for Minia City, which can be exported to other regions with comparable climates. These strategies are practically and effectively considered functional architectural approaches that can improve thermal comfort for people. The two tools CC and MT are compared based on 27 recommended strategies that can be achieved according to the bioclimatic parameters that were studied. They agreed with 30% as good natural ventilation, passive solar heating with a high percentage that reached 10% for each. Where there is a difference of 20 recommendations to 70%, this represents other factors or recommendations such as shading with which it is proposed in MT as well as other parameters.

Performance prediction of a novel disinfection-enhanced type Trombe wall with transverse fins

Trombe wall is an efficient passive solar heating system, while the utilization form of heated air needs to be expanded. Indoor microorganisms that can be transmitted through aerosol endanger the safety of human health. The fact that microorganisms can be thermally inactivated makes it possible to disinfect the air through Trombe wall. To expand and enhance the disinfection effect of the wall, extending the residence time of bioaerosols in the flow channel and raising the air temperature can be applied. Therefore, a transverse-finned-Trombe wall is proposed. Multiple physical field coupling is studied numerically. Migration, inactivation, and deposition of bioaerosols are described by Eulerian method. The results indicated as follows: As fin height increases, the thermal efficiency first rises and then drops; the single-pass inactivation ratio rises remarkably with its value reaching 90.96 % and 66.98 % for SARS-CoV-1 and SARS-CoV-2 even at low irradiance level (400 W/m2) at a fin height of 35 mm. As fin angle increases from −45° to +45°, the thermal efficiency drops first and then rises. Optimal disinfection performance is achieved at α = 0°. The contribution of deposition to removal of infectious bioaerosols plays a significant role when the thermal inactivation is not strong.

Assessment of Passive Solar Heating Systems’ Energy-Saving Potential across Varied Climatic Conditions: The Development of the Passive Solar Heating Indicator (PSHI)

This study aims to evaluate the energy-saving potential of passive solar heating systems in diverse global climates and introduce a new indicator, the passive solar heating indicator (PSHI), to enhance the efficiency of building designs. By collecting climate data from 600 cities worldwide through a simulation model, the present study employs polynomial regression to analyze the impact of outdoor temperature and solar radiation intensity on building energy savings. It also uses K-means cluster analysis to scientifically categorize cities based on their energy-saving potential. The findings underscore the benefits of both direct and indirect solar heating strategies in different climates. Significantly, the PSHI shows superior predictive accuracy and applicability over traditional indices, such as the irradiation temperature difference ratio (ITR) and the irradiation degree hour ratio (C-IDHR), especially when outdoor temperatures are close to indoor design temperatures. Moreover, the application of a cluster analysis provides hierarchical guidance on passive heating designs globally, paving the way for more accurate and customized energy-efficient building strategies.

Sustainable Development of Landscape Architecture from the Perspective of Energy and Environment Management

A major concern in the field of landscape architecture is sustainable development. The goal of this strategy is to provide design solutions that satisfy current demands without jeopardizing the capacity of future generations to satisfy their own. The viewpoint of energy and environmental management is crucial for achieving sustainable development in landscape architecture. Energy management is essential to landscape architecture because it involves resource efficiency, reducing energy usage, and integrating renewable energy sources. It includes incorporating strategies like passive solar design, proper material selection, and the use of green infrastructure systems. These practices not only promote eco-friendly designs but also reduce the cost of maintenance and operation in the long term. Environmental management focuses on preserving and enhancing the natural environment through sustainable land use practices.

Passive Solar Energy Building

Passive Solar Energy Building

Annual Energy-Saving Smart Windows with Actively Controllable Passive Radiative Cooling and Multimode Heating Regulation.

Smart windows with radiative heat management capability using the sun and outer space as zero-energy thermodynamic resources have gained prominence, demonstrating a minimum carbon footprint. However, realizing on-demand thermal management throughout all seasons while reducing fossil energy consumption remains a formidable challenge. Herein, an energy-efficient smart window that enables actively tunable passive radiative cooling (PRC) and multimode heating regulation is demonstrated by integrating the emission-enhanced polymer-dispersed liquid crystal (SiO2@PRC PDLC) film and a low-emission layer deposited with carbon nanotubes. Specifically, this device can achieve a temperature close to the chamber interior ambient under solar irradiance of 700W m-2, as well as a temperature drop of 2.3°C at sunlight of 500W m-2, whose multistage PRC efficiency can be rapidly adjusted by a moderate voltage. Meanwhile, synchronous cooperation of passive radiative heating (PRH), solar heating (SH), and electric heating (EH) endows this smart window with the capability to handle complicated heating situations during cold weather. Energy simulation reveals the substantial superiority of this device in energy savings compared with single-layer SiO2@PRC PDLC, normal glass, and commercial low-E glass when applied in different climate zones. This work provides a feasible pathway for year-round thermal management, presenting a huge potential in energy-saving applications.

Dynamical Janus-Like Behavior Excited by Passive Cold-Heat Modulation in the Earth-Sun/Universe System: Opportunities and Challenges.

The utilization of solar-thermal energy and universal cold energy has led to many innovative designs that achieve effective temperature regulation in different application scenarios. Numerous studies on passive solar heating and radiation cooling often operate independently (or actively control the conversion) and lack a cohesive framework for deep connections. This work provides a concise overview of the recent breakthroughs in solar heating and radiation cooling by employing a mechanism material in the application model. Furthermore, the utilization of dynamic Janus-like behavior serves as a novel nexus to elucidate the relationship between solar heating and radiation cooling, allowing for the analysis of dynamic conversion strategies across various applications. Additionally, special discussions are provided to address specific requirements in diverse applications, such as optimizing light transmission for clothing or window glass. Finally, the challenges and opportunities associated with the development of solar heating and radiation cooling applications are underscored, which hold immense potential for substantial carbon emission reduction and environmental preservation. This work aims to ignite interest and lay a solid foundation for researchers to conduct in-depth studies on effective and self-adaptive regulation of cooling and heating.