Zero energy buildings and sustainable development implications ― A review

Heating, ventilating, and air-conditioning (HVAC) are parts of the major energy consumption in a building. Conventional heating and cooling systems are having an impact on carbon dioxide emissions, as well as on security of energy supply. In this regard, one of the attempts taken by researchers is the development of solar heating and cooling technologies. The objective of this paper is to review the passive solar technologies for space heating and cooling. The reviews were discussed according to the working mechanisms, i.e. buoyancy and evaporative effects. The advantages, limitations and challenges of the technologies have been highlighted and the future research needs in these areas have also been suggested.

Review of passive solar heating and cooling technologies

Thermal performance of a single basin solar still with PCM as a storage medium

Based on United Nations Environment Program (UNEP), building sector accounts for 40% of total energy consumption. In European countries, 36% of total greenhouse gas emissions is attributed to buildings. In this respect, green roofs are considered to be one of the most appropriate sustainable solutions to resolve the urban heat island-related issues. Roofs account for nearly 20–25% of overall urban surface areas. Energy saving, thermal insulation, shading and evapotranspiration features highlight the key role of green roofs in overall thermal performance of buildings and microclimatic conditions of indoor environments. Within the scope of this research, the concept of green roofs and facades is comprehensively analysed in a holistic and thematic way. Following a historical overview of the technology, the research is split into various subfields such as energy saving in buildings through greenery systems, multifunctional thermal benefits including evapotranspiration, thermal insulation, shading and thermal comfort features, evaporative cooling for reducing cooling demand and minimising wind driven convection losses. The results achieved from the literature survey clearly indicate that green roofs and facades are key solutions to mitigate building-related energy consumptions and greenhouse gas emissions. According to the previous works, heat flow through the building roofs in summer can be reduced by approximately 80% via green roofs. The green roofs are reported to consume less energy in the range of 2.2–16.7% than traditional roofs during summer time. A similar tendency is observed for the winter season depending on regional and climatic conditions. The temperature difference between conventional and greens roofs in winter is found to be about 4 °C, which is remarkable. Energy demand of buildings in summer is highly dependent on the plant intensity as it is reported to be 23.6, 12.3 and 8.2 kWh/m2/year for extensive, semi-intensive and intensive greenery surface, respectively. Greenery systems are also capable of providing thermally comfortable indoor and outdoor conditions. It is underlined that the annual average accumulation of CO2 reaches the level of 13.41–97.03 kg carbon/m2 for 98 m2 of vertical greenery system. The results of this research can be useful for dwellers, builders, architects, engineers and policy makers to have a good understanding about the potential of green roofs and facades to mitigate building-related energy consumptions and carbon emissions in a renewable, sustainable, energy-efficient and cost effective way.

Green roofs and facades: A comprehensive review

Thermal Energy Storage (TES) has been a topic of research for quite some time and has proven to be a technology that can have positive effects on the energy efficiency of a building by contributing ...

Combining thermal energy storage with buildings – a review

Study of natural ventilation of houses by a metallic solar wall under tropical climate

Performance improvement of the combined cycle power plant by intake air cooling using an absorption chiller

This article presented an indoor experiment on developing a mathematical model for predicting the productivity of an ethanol solar still of basin type. The test still contained a horizontal evaporating surface and a condensing surface inclined 14° to a horizontal. Various concentrations of ethanol–water solution were employed for this experiment. The distillation temperature range included boiling point. The collected data were used to estimate the mass-transfer coefficient and mass transfer conductance of the solar still. Accordingly, a mathematical model was developed based on the Spalding theory of convection and the Fick's law of diffusion. In order to increase the performance at the outdoor conditions, a basin solar still was integrated with a set of fin-plate fitting in the still basin for distillation of a 10%v/v alcohol solution. It was found that the productivity of the modified solar still was increased by 15.5%, compared to that of a conventional still. Moreover, the predicted still efficiency by the model could increase to 46% when a number of fins that raised an effective absorptance were increased. Condition of high concentration output and high productivity was investigated. Monthly mean productivity and efficiency of the still were found to increase with daily mean insolation.

Pichai Namprakai

Papers

Study of natural ventilation of houses by a metallic solar wall under tropical climate

Performance improvement of the combined cycle power plant by intake air cooling using an absorption chiller

The thermal performance of an ethanol solar still with fin plate to increase productivity

Cooling performance and condensation evaluation of horizontal earth tube system for the tropical greenhouse

The thermal performance of an ethanol solar still with fin plate to increase productivity