A SIMULATION BASED STUDY OF ENERGY CONSERVATION OF RESIDENCES IN LAHORE, PAKISTAN

A house in composite climate of Lahore (Pakistan) needs intensive cooling in summers; energy recovery ventilation to reduce humidity during monsoon and comfortable indoor temperature during winters. All these conditions have to be fulfilled with a reduced load on energy resources. Recent trends in construction and design of residential buildings in Pakistan symbolize uncontrolled use of energy resources. There is no data available with planning and developing authorities of housing sector that shows an account of energy loads of built houses. The potential of conservation of energy will be analyzed by actually studying the cooling and heating loads of recently constructed houses Key Words: Energy Conservation Potential, Module Study, Simulations

Concentrated Solar Power (CSP) for Sustainable Architecture to Supply Domestic Hot Water and Heating Loads of Buildings

Parabolic Trough Concentrators (PTC) are the most common solar concentrators. However, the high cost of production, operation, sun- tracking system, and the environmental sensitivity made them unprofitable for urban contexts. Lenses are more efficient and effective, but the complexity of manufacturing made them less used in sustainable architecture. This research proposes a liquid lens to be integrated into buildings’ envelope and compared with a PTC based on the energy production and reduced CO2 emissions over a year. The output energy, temperature, and efficiency of concentrator are obtained by the physics of light equations, and Ray-tracing software simulation. The results show that water lenses are at least 6% more efficient, their output temperature is higher, their underneath greenhouse effect made them less sensitive to the environment, and are still productive in high latitudes where PTCs are not operative. The paper presents the full result of the research that was registered as a patent.

State-of-the-Art Technologies for Building-Integrated Photovoltaic Systems

Advances in building-integrated photovoltaic (BIPV) systems for residential and commercial purposes are set to minimize overall energy requirements and associated greenhouse gas emissions. The BIPV design considerations entail energy infrastructure, pertinent renewable energy sources, and energy efficiency provisions. In this work, the performance of roof/façade-based BIPV systems and the affecting parameters on cooling/heating loads of buildings are reviewed. Moreover, this work provides an overview of different categories of BIPV, presenting the recent developments and sufficient references, and supporting more successful implementations of BIPV for various globe zones. A number of available technologies decide the best selections, and make easy configuration of the BIPV, avoiding any difficulties, and allowing flexibility of design in order to adapt to local environmental conditions, and are adequate to important considerations, such as building codes, building structures and loads, architectural components, replacement and maintenance, energy resources, and all associated expenditure. The passive and active effects of both air-based and water-based BIPV systems have great effects on the cooling and heating loads and thermal comfort and, hence, on the electricity consumption.

Evaluating the Effect of External Horizontal Fixed Shading Devices’ Geometry on Internal Air Temperature, Daylighting and Energy Demand in Hot Dry Climate. Case Study of Ghardaïa, Algeria

The present study investigates the effect of fixed external shading devices’ geometry on thermal comfort, daylighting and energy demand for cooling and heating in the hot and dry climate of the city of Ghardaïa (Algeria). A parametric analysis was performed by using three software: RADIANCE 2.0 and DAYSIM 3.1 for daylighting simulation and TRNSYS.17 for thermal dynamic simulation. Three shading device parameters were assessed: the spacing between slats, the tilted angle and the slats installation. The vertical shading angle “VSA” is fixed; it is equal to the optimum shading angle measured for Ghardaïa. The simulation results indicate that fixed external shading devices have a significant impact on decreasing the energy demand for cooling; however, they are unable to reduce the total energy demand since they significantly increase heating loads. It was found that fixed external shading devices remove all risks associated with glare in summer by decreasing illuminance close to the window; however, they do not improve daylighting performance in winter because of glare. We note that even if the vertical shading angle “VSA” was the same for all cases, these did not present the same thermal and luminous behavior. This is mainly due to the amount and the way that the solar radiation penetrates space.