Potential energy savings from cool roofs in South Africa

Abstract: Cool roofs are beneficial for most buildings almost everywhere in the world. They are described as an inexpensive method in order to improve the comfort level in buildings in mild and hot climate or save energy. However, their cost-effectiveness can vary significantly, depending on climate and local factors. Therefore, the use of simulations with local conditions can provide the clarity required in order to deploy cool roofs in a particular location. This paper presents an estimation of the potential energy savings resulting from the use of cool roofs for different climatological conditions within South Africa. Several cities have been selected across South Africa and climatological data have been obtained from the NASA Atmospheric Science Data Center. The DOE Cool Roof Calculator was adapted for the estimation of cooling and heating saving corresponding to specific type of roofs and climatological variables within these selected cities. The preliminary results strongly suggest that cool roofs yield positive potential savings in residences using electrical heating for most of the cities studied

Design model of a novel cooling condensation type atmospheric water generator for coastal rural South Africa

Abstract: In many of South Africa’s rural communities, rivers and rain water storage tanks are the main source for domestic water supply and agricultural use. However, from 2015 to date South Africa has faced severe water shortages due to the worst droughts the country has experienced in over 23 years. The droughts have led to the reduction in flow volumes of some rivers and domestic rain water storage tanks being rendered mostly empty. This greatly endangered the livelihoods of many rural communities in South Africa. This study investigates the implementation of an affordable cooling condensation type Atmospheric Water Generator (AWG) solution for coastal rural households as a supplementary water source in the event of water crisis. The eastern coastal region of KwaZulu-Natal (KZN), situated between the towns of Amanzimtoti and St. Lucia, was chosen as the case study location due to the favourable climate conditions for the implementation of AWG technology as well as the large number of surrounding rural communities that have been affected by the on-going draughts..

Development of solar powered water purification systems

Abstract: In this paper, we highlight the effects of contaminated water on humans as well as the crisis of water supply and distribution of potable water in many areas of developing countries. Water is the most important substance on earth. While water is a primary human need, contaminated water can cause and spread diseases. It is, therefore, necessary to ensure that water is purified and decontaminated for daily use at a low-cost. Therefore, the design of solar-powered water purification systems is considered to produce clean water. Solar energy poses no polluting effect; thus, has become a dependable energy source for usage. The design of a solar-powered water purification system is based totally on the thermal method by using the thermal heating system principle. This principle converts sunlight rays into heat. The most vital aspect is the absorption of heat to induce evaporation of water. Research shows that flat plate collectors produce heat at relatively low temperatures (27°C to 60°C) and are commonly used to heat liquids. A solar-powered water purification system consists of a solar collector that absorbs sunlight to ensure vaporisation which is the first stage of purifying and a filter that removes contaminants. Four different concepts have been developed. A detailed description of the components and the operation of the systems constitute the main contribution of this paper

Experimental study of part load performance of a counter flow cooling tower

Abstract: Please refer to full text to view abstract

Thermodynamics 3

Exam paper (Supplementary) for first semester National Diploma (Mechanical Engineering Technology

Thermodynamics II (Supplementary Examination)

Exam paper for second semester summer supplementary examination 2014, National Diploma Engineering: Mechanica