Deo Prasad

Designing with solar power : a source book for building integrated photovoltaics (BiPV)

Designing With Solar Power encapsulates five years of work by over thirty international experts from the fields of research, development and design. Photovoltaic (PV) powers potential for wide distribution makes it a unique and novel energy source that can be embedded within the fabric of individual buildings, shifting power generation away from being large scale and regionally located. As a consequence, an abundantly available, clean and silent electrical supply can be introduced into cities, towns and built-up areas. This in-depth highly illustrated publication shows a clear path to the way of designing with photovoltaic in buildings and is very important for any designer or individual that wishes to keep up with this new and exciting technology.

Thermographic analysis of a building integrated photovoltaic system

A residential-scale building integrated photovoltaic (BiPV) cogeneration system has been thermographically investigated. The results are useful in calibrating the numerical models created to predict the systems operational temperatures. The combined heat and power system is based on existing BiPV roofing technology with the addition of a modular heat recovery unit. The convection of the air behind the panels will serve both to cool the photovoltaic panels and provide a heat source for the residence. The analysis allows for the interpretation of the surface emissivities and operating temperatures, as well as qualitative graphic analysis of temperature gradients.

Modelling of a photovoltaic heat recovery system and its role in a design decision support tool for building professionals

A numerical model has been created to simulate the performance of a residential-scale building integrated photovoltaic (BiPV) cogeneration system. The investigation examines the combined heat and power system in the context of heat transfer. The PV cogeneration system will be based on existing BiPV roofing technology with the addition of a modular heat recovery unit that can be used in new or renovation construction schemes. The convection of the air behind the panels will serve to cool the PV panels while providing a heat source for the residence. This model was created in the Engineering Equation Solver software package (EES), from a series of highly coupled non-linear partial differential equations that are solved iteratively. The models ability to utilize climatic data to simulate annual performance of the system will be presented along with a comparison to experimental data. A graphical front-end has been added to the model in order to facilitate its use as a predictive tool for building professionals. It will thus become a decision support tool used in identifying areas for implementation of a PV cogen system.

Impacts of green certifications, ventilation and office types on occupant satisfaction with indoor environmental quality

One of the important reasons for the interest in green buildings is that the employees can benefit from healthy and productive work environments. This research aims to provide evidence that can affect design decisions by a literature review and an occupant survey. Three important design decisions (green certifications, ventilation types and office types) were investigated through a standard occupant survey in China. Highly rated green buildings could be effective to provide a comfortable, healthy and productive work environment. Mixed-mode ventilation (a hybrid approach to space conditioning that uses a combination of natural ventilation and mechanical systems) and high cubicles (open-plan offices with high partitions) are sensible choices for green buildings to achieve high environmental satisfactions.

THE EFFECTS OF BALCONIES ON THE NATURAL VENTILATION PERFORMANCE OF CROSS-VENTILATED HIGH-RISE BUILDINGS

ABSTRACT Natural ventilation performance can be influenced by various factors, including facade treatments such as balconies. Balconies have been commonly incorporated into residential buildings for various purposes, yet the provision of a balcony as a passive design strategy to improve natural ventilation is not one of its common purposes. The objective of this study is to investigate the effect of balcony design on the natural ventilation performance of cross-ventilated high-rise apartments. This study uses Computational Fluid Dynamics (CFD) models to predict ventilation performance. CFD models are selected because of their accuracy, flexibility and ability to provide comprehensive data for the investigation. This study suggests that balconies in high-rise apartments could improve the ventilation performance of high-rise apartments, but that balconies can also have a negative impact on ventilation performance if not appropriately designed. Finally, this study suggests that balconies could improve the le...

Status report of Task VII of the IEA program: PV in buildings

On January 1, 1997, a new Task started within IEAs PV Power Systems Program: Task VII. Objective of Task VII is to enhance the architectural quality, the technical quality and the economic viability of PV systems in the built environment and to assess and remove non-technical barriers for their introduction as an energy-significant option.

Modeling Efficient Building Design: A Comparison of Conditioned and Free-Running House Rating Approaches

Abstract There has long been a concern that rating building thermal performance based on predicted space loads in conditioned mode is inappropriate to achieve overall energy efficiency of houses in temperate climates. Buildings designed to be free running may achieve better results using a more appropriate rating system. This study, using simulation, predicts the thermal performance of houses in two different operation modes: conditioned and free running. The thermal performance of houses in the conditioned mode is indicated by predicted annual energy requirements (MJ/m2). Thermal performance in the free-running mode is indicated by annual degree discomfort hours (DDH). The paper investigates the correlation between the indicator of thermal performance of simulated houses in a conditioned operation mode and the indicator of thermal performance of those houses in a free-running operation mode. Despite a strong relationship between these two indicators, some significant differences become clear leading to a discussion of the persistent technical problems and issues that are encountered when attempting to optimize energy efficient architectural designs. The results of this study confirm the necessity of a new House Rating Scheme (HRS) incorporating an appropriate indicator for free-running buildings.

Application of "Streamlined" Material Input per Service Unit Concept to Small Residential Districts in China

This article reports a new application of material and energy accounting techniques to characterize and quantify the relationships between material input (and the related energy flows and emissions) and the services provided (i.e., material input per service unit [MIPS]) at the neighborhood level. The case study focuses on Chinas small residential district (SRD). It is concluded that linking a service (in this case, residential function) enabled by a given product (neighborhood development) to the amount of materials, energy, and emissions used or produced in creating that product offers a potential way to reduce the environmental impact of that service through more efficient use of materials, enlarged service scales, and improved buying decisions.

Bonnyrigg solar village: An analysis of annual energy use and comfort

Abstract In 1981, 12 solar-efficient houses and 3 standard houses were designed and built for the New South Wales Housing Commission near Sydney, Australia. Recently, a pilot study was done to evaluate the energy use and comfort levels in these 15 houses over a two-year period. Heavyweight, well insulated houses, as a group, used the least energy annually, averaging 19,235 MJ in 1983–1984. They are least likely to require winter space heating, which typically contributes 31% of the total energy bill. A trade-off of a well insulated house is less comfort in the summer unless active measures are taken by the residents to open windows in the evenings and close shades in the day for effective cooling. Even so, the four houses with heavyweight wall construction remained in the daytime comfort zone an average of 76% of the time in 1983. The annual energy use in the houses was compared to other studies done in Australia. The average energy consumption of the 12 passive solar homes was 22,687 MJ/year in the two-year period 1983–1984. Bartels (1985) found the average household consumption in New South Wales to be 28,000 MJ. The three control houses used 30,059 MJ/year on average, though the sample size was considerably smaller, and thus more likely to be affected by atypical user behavior. This study provides clear evidence of the effectiveness of solar efficient design in significantly reducing winter heating loads.

The Potential of Natural Ventilation in Single-Sided Ventilated Apartment to Improve Indoor Thermal Comfort and Air Quality

Cross ventilation is a more effective ventilation strategy in comparison to single-sided ventilation. In the NSW Residential Flat Design Code1 (RFDC) the majority of apartments are required to adopt cross ventilation. However, in the case of studio and one-bedroom apartments, it is acknowledged that single-sided ventilation may prevail. Deep plan studio and one-bedroom apartments may achieve lower amenity of summer thermal comfort and indoor air quality where mechanical ventilation is not provided by air conditioning. Since compliance with the code may allow up to 40% of apartments in a development in Sydney to be single sided, it is important to understand the natural ventilation performance of such apartments. The objective of this paper is to investigate the natural ventilation potential in single-sided ventilated apartments to improve indoor air quality and thermal comfort. This investigation includes simulating various facade treatments involving multiple opening and balcony configurations. Balcony configurations are included in this study because, in Sydney, a balcony is a compulsory architectural element in any apartment building. The study uses computational fluid dynamics (CFD) software to simulate and predict the ventilation performance of each apartment configuration. This study suggests that properly configured balconies and openings can significantly improve indoor ventilation performance for enhanced indoor air quality and thermal comfort, by optimizing the available prevailing wind. However, it is important to note that inappropriately designed facade treatments also could diminish natural ventilation performance.Copyright