Evaluation of savings from an underground fan replacement project
- De Canha, D., Pretorius, J.H.C., Laubscher, R., Van Rhyn, P.
- Authors: De Canha, D. , Pretorius, J.H.C. , Laubscher, R. , Van Rhyn, P.
- Date: 2016
- Subjects: Measurement and verification , Energy efficiency , Underground ventilation
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/213676 , uj:21182 , De Canha, D. et al. 2016. Evaluation of savings from an underground fan replacement project.
- Description: Abstract: The savings calculation methodology from a fan replacement project is presented in this paper. The fans replaced are part of the underground ventilation system in a platinum mine. Initially, 290 axial flow fans rated at 45kW were to be replaced with carbon fibre composite fans. According to the manufacturer, the carbon fibre construction allowed for an optimum blade shape which results in the carbon fibre fan being more energy efficient. However, after the first few fans were replaced, it was discovered that the mine’s blasting activities caused the carbon fibre fans to crack and eventually fail. Fortunately, the manufacturer was able to produce a steel fan with similar performance to that of the carbon composite fans and continue replacing old fans in the mine. The savings were independently verified according to the International Performance Measurement & Verification Protocol (IPMVP). This involved testing old and new fans in a BS848 test duct and comparing the old and new fans at various operating points on their fan curves and making adjustments for operating conditions such as air density underground vs at the test duct. It was found that the new fans saved 5kW on average, across a range of operating points.
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- Authors: De Canha, D. , Pretorius, J.H.C. , Laubscher, R. , Van Rhyn, P.
- Date: 2016
- Subjects: Measurement and verification , Energy efficiency , Underground ventilation
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/213676 , uj:21182 , De Canha, D. et al. 2016. Evaluation of savings from an underground fan replacement project.
- Description: Abstract: The savings calculation methodology from a fan replacement project is presented in this paper. The fans replaced are part of the underground ventilation system in a platinum mine. Initially, 290 axial flow fans rated at 45kW were to be replaced with carbon fibre composite fans. According to the manufacturer, the carbon fibre construction allowed for an optimum blade shape which results in the carbon fibre fan being more energy efficient. However, after the first few fans were replaced, it was discovered that the mine’s blasting activities caused the carbon fibre fans to crack and eventually fail. Fortunately, the manufacturer was able to produce a steel fan with similar performance to that of the carbon composite fans and continue replacing old fans in the mine. The savings were independently verified according to the International Performance Measurement & Verification Protocol (IPMVP). This involved testing old and new fans in a BS848 test duct and comparing the old and new fans at various operating points on their fan curves and making adjustments for operating conditions such as air density underground vs at the test duct. It was found that the new fans saved 5kW on average, across a range of operating points.
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Negative energy impacts in the absence of proper baseline studies - a South African case study
- Pretorius, J.H.C., Van Rhyn, P., De Canha, D.
- Authors: Pretorius, J.H.C. , Van Rhyn, P. , De Canha, D.
- Date: 2016
- Subjects: Measurement and verification , Energy efficiency , Underground ventilation
- Language: English
- Type: Conference proceedings
- Identifier: http://ujcontent.uj.ac.za8080/10210/368139 , http://hdl.handle.net/10210/213583 , uj:21171 , Citation: Pretorius, J.H.C., Van Rhyn, P & De Canha, D. 2016. Negative energy impacts in the absence of proper baseline studies - a South African case study.
- Description: Abstract: Energy Conservation projects have become a focus area throughout the world in an attempt to reduce greenhouse gasses. These projects encompass various energy efficient technologies of which the retrofit of old technologies with new technology has become a common phenomenon. Energy savings are usually quantified by comparing actual post-retrofit energy consumption levels with baseline levels representative of the preretrofit status quo, adjusted for changes in energy drivers (e.g. weather). Baseline adjustments during energy conservation projects are of the utmost importance if operating conditions, occupancies, ambient temperatures, production levels and other factors have changed between the baseline period and the postretrofit period. During a recent case study in South Africa, an HVAC retrofit was done on a multistorey building where old technology air-conditioners were replaced with heat pump based units with inverters. To the disappointment of the landlord, the post energy measurements exceeded the baseline energy consumption by approximately 12% without any changes in operating conditions. This paper illustrates the catastrophic effects when an energy efficiency project is accelerated to the implementation stage without due consideration of operating conditions during the pre-implementation stage. A qualitative analysis prior to baseline establishment is proposed.
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- Authors: Pretorius, J.H.C. , Van Rhyn, P. , De Canha, D.
- Date: 2016
- Subjects: Measurement and verification , Energy efficiency , Underground ventilation
- Language: English
- Type: Conference proceedings
- Identifier: http://ujcontent.uj.ac.za8080/10210/368139 , http://hdl.handle.net/10210/213583 , uj:21171 , Citation: Pretorius, J.H.C., Van Rhyn, P & De Canha, D. 2016. Negative energy impacts in the absence of proper baseline studies - a South African case study.
- Description: Abstract: Energy Conservation projects have become a focus area throughout the world in an attempt to reduce greenhouse gasses. These projects encompass various energy efficient technologies of which the retrofit of old technologies with new technology has become a common phenomenon. Energy savings are usually quantified by comparing actual post-retrofit energy consumption levels with baseline levels representative of the preretrofit status quo, adjusted for changes in energy drivers (e.g. weather). Baseline adjustments during energy conservation projects are of the utmost importance if operating conditions, occupancies, ambient temperatures, production levels and other factors have changed between the baseline period and the postretrofit period. During a recent case study in South Africa, an HVAC retrofit was done on a multistorey building where old technology air-conditioners were replaced with heat pump based units with inverters. To the disappointment of the landlord, the post energy measurements exceeded the baseline energy consumption by approximately 12% without any changes in operating conditions. This paper illustrates the catastrophic effects when an energy efficiency project is accelerated to the implementation stage without due consideration of operating conditions during the pre-implementation stage. A qualitative analysis prior to baseline establishment is proposed.
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Novel approach for concentrating and harvesting solar radiation in hybrid transparent photovoltaic façade’s in Southern Africa.
- Gevers, R.H., Pretorius, J.H.C., Van Rhyn, P.
- Authors: Gevers, R.H. , Pretorius, J.H.C. , Van Rhyn, P.
- Date: 2016
- Subjects: Transparent solar cell , Solar , Solar energy
- Language: English
- Type: Conference proceeding
- Identifier: http://hdl.handle.net/10210/91838 , uj:20152 , Citation: Gevers, R.H., Pretorius, J.H.C. & Van Rhyn, P. 2016. Novel approach for concentrating and harvesting solar radiation in hybrid transparent photovoltaic façade’s in Southern Africa.
- Description: Abstract: Electrical consumption and the price thereof is rapidly increasing in South Africa. Finding alternatives to the current grid-tied electricity supply in the country is a prodigious concern to the South African economy due to historic unreliability. The national power grid and the South African economy can extensively benefit from utilizing solar energy as an abundant clean and renewable energy source. This paper considers and further investigates power generation utilising a novel approach to transparent solar façades (windows). Harvesting solar energy is consequently included in the building envelope, which improves building efficiency while reducing demand on the national electric grid. The impacts, design, modelling and results of this novel approach to Photo Voltaic (PV) systems, is further examined in this paper. These systems are aimed to be used in the commercial and residential market. Factoring in the location, design and installation of the solar façade, geographical conditions relevant to South Africa were used to evaluate the transparent façade’s performance. The generated power from a façade depends on solar irradiation, orientation, (Azimuth and Zenith angles); climate conditions such as temperature and rainfall; and other solar constraints. These factors were incorporated using average values from meteorological data.
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- Authors: Gevers, R.H. , Pretorius, J.H.C. , Van Rhyn, P.
- Date: 2016
- Subjects: Transparent solar cell , Solar , Solar energy
- Language: English
- Type: Conference proceeding
- Identifier: http://hdl.handle.net/10210/91838 , uj:20152 , Citation: Gevers, R.H., Pretorius, J.H.C. & Van Rhyn, P. 2016. Novel approach for concentrating and harvesting solar radiation in hybrid transparent photovoltaic façade’s in Southern Africa.
- Description: Abstract: Electrical consumption and the price thereof is rapidly increasing in South Africa. Finding alternatives to the current grid-tied electricity supply in the country is a prodigious concern to the South African economy due to historic unreliability. The national power grid and the South African economy can extensively benefit from utilizing solar energy as an abundant clean and renewable energy source. This paper considers and further investigates power generation utilising a novel approach to transparent solar façades (windows). Harvesting solar energy is consequently included in the building envelope, which improves building efficiency while reducing demand on the national electric grid. The impacts, design, modelling and results of this novel approach to Photo Voltaic (PV) systems, is further examined in this paper. These systems are aimed to be used in the commercial and residential market. Factoring in the location, design and installation of the solar façade, geographical conditions relevant to South Africa were used to evaluate the transparent façade’s performance. The generated power from a façade depends on solar irradiation, orientation, (Azimuth and Zenith angles); climate conditions such as temperature and rainfall; and other solar constraints. These factors were incorporated using average values from meteorological data.
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Utilising high and premium efficiency three phase motors with VFDs in a public water supply system
- Van Rhyn, P., Pretorius, J.H.C.
- Authors: Van Rhyn, P. , Pretorius, J.H.C.
- Date: 2015-05-13
- Subjects: Centrifugal pump systems , Energy efficiency , Variable frequency drives
- Type: Article
- Identifier: uj:5107 , ISBN 978-1-4799-9978-1 , http://hdl.handle.net/10210/13929
- Description: The increased reliability and ultimately reduced life cycle cost of high and premium efficiency three phase motors in a process control application is discussed. The reduced energy consumption of these motors is evaluated in a public water system case study under variable frequency conditions. The importance of the consideration of a combined system, which includes variable speed control, motor and load - as opposed to only replacing with high efficiency motors for energy saving purposes - is practically observed and reported on. The paper reports on the marginal improvement in energy consumption at reduced supply frequency for motor replacement only (not surprising) but a very impressive 46% saving in energy consumption by controlling pumped water at a reduced but constant delivery rate.
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- Authors: Van Rhyn, P. , Pretorius, J.H.C.
- Date: 2015-05-13
- Subjects: Centrifugal pump systems , Energy efficiency , Variable frequency drives
- Type: Article
- Identifier: uj:5107 , ISBN 978-1-4799-9978-1 , http://hdl.handle.net/10210/13929
- Description: The increased reliability and ultimately reduced life cycle cost of high and premium efficiency three phase motors in a process control application is discussed. The reduced energy consumption of these motors is evaluated in a public water system case study under variable frequency conditions. The importance of the consideration of a combined system, which includes variable speed control, motor and load - as opposed to only replacing with high efficiency motors for energy saving purposes - is practically observed and reported on. The paper reports on the marginal improvement in energy consumption at reduced supply frequency for motor replacement only (not surprising) but a very impressive 46% saving in energy consumption by controlling pumped water at a reduced but constant delivery rate.
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