SciELO - Scientific Electronic Library Online

vol.23 número3A techno-economic study of energy efficiency technologies for supermarkets in South AfricaPerformance of A R22 split-air-conditioner when retrofitted with ozone friendly refrigerants (R410A and R417A) índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados



Links relacionados

  • En proceso de indezaciónCitado por Google
  • En proceso de indezaciónSimilares en Google


Journal of Energy in Southern Africa

versión On-line ISSN 2413-3051
versión impresa ISSN 1021-447X

J. energy South. Afr. vol.23 no.3 Cape Town  2012


Efficiency and cost analysis of a designed in-line water heating system compared to a conventional water heating system in South Africa



Rupert Gouws; Estie le Roux

School of Electrical, Electronic and Computer Engineering, North-West University, Potchefstroom, South Africa




In this paper, the authors compares the efficiency and cost of a designed in-line water heating system with a conventional water heating system (geyser) in South Africa. The paper provides an overview on water heating systems and heating elements and provides the typical water consumption required by an average household in South Africa. A summary on the design of the in-line water heating system together with a system cost analysis is provided. The designed in-line water heating system takes the energy consumption, temperature and pressure into account during operation. The energy consumption and cost of the designed in-line water heating system is compared to a conventional water geyser. A cost analysis on the designed in-line water heating system, heat pumps and solar water heating systems are also provided. The energy consumption results showed that the conventional water geyser on average consumes 2.5% more energy to heat one litre of water from 15 °C to 60 °C, than the designed in-line water heating system to supply one litre of water at 60°C.

Keywords: efficiency analysis, cost analysis, in-line water heating system, conventional water heating system, design and monitoring



Full text available only in PDF format.




ACME, (2010). How does a water heater work. Available at         [ Links ]

DEAT, (2004). A national climate change response strategy for South Africa. Department of environmental affairs and tourism. Available at, Pretoria, September 2004.         [ Links ]

EDRC, (2003). Electricity consumption in South African households accounts for approximately 35% of peak demand. Available at         [ Links ]

Etankless, (2010). Compare electric tankless water heaters. Available at (Accessed: Dec. 2010).         [ Links ]

Ilsette P, (2010). SWH information handbook,         [ Links ] [Online] Available at (Accessed: Dec. 2010]).

Klenck T., (1997). How it works: Water Heater. Available at (Accessed: Dec. 2010).         [ Links ]

LaMeres B.J., Nehrir M.H., Gerez V., (1999). Controlling the average residential electric water heater power demand using fuzzy logic, Journal on Electric Power Systems Research, Vol. 52, Issue 3, December 1999, pp. 267-271.         [ Links ]

Le Roux E., Gouws R., (2011). Design of an in-line water heating system, North-West University, Project document, Faculty of Engineering, June 2011.         [ Links ]

Omega, (2011). Introduction to immersion Heaters. Available at (Accessed: Jan 2011).         [ Links ]

Prud'homme T., Gillet D., (2001). Advanced control strategy of a solar domestic hot water system with a segmented auxiliary heater, Journal on Energy and Buildings, Vol. 33, Issue 5, May 2001, pp. 463-475.         [ Links ]

Rollins G., (2010). Inline hot water heaters. Available at (Accessed: Nov. 2010).         [ Links ]

Sebitosi A.B., (2008). Energy efficiency, security of supply and the environment in South Africa: Moving beyond the strategy documents, Journal on Energy, Vol. 33, Issue 11, November 2008, pp. 1591-1596.         [ Links ]

Sebitosi, A.B., Pillay P., (2008). Renewable energy and the environment in South Africa: A way forward. Journal on Energy Policy, Vol. 36, Issue 9, September 2008, pp 3312-3316.         [ Links ]

Sowmy D.S., Prado R.T.A., (2008). Assessment of energy efficiency in electric storage water heaters, Elsevier Journal on Energy and Buildings, Vol. 40, Issue 12, pp. 2128-2132.         [ Links ]

Swiftheat, (2011). Industrial heating elements. Available at (Accessed: June 2011).         [ Links ]

Tempco, (2011). Screw plug immersion heaters. Available at (Accessed: March 2011).         [ Links ]

van Amerongen C., (1972). How things work, The Universal Encyclopaedia of Machines, Paladin/Granada Publishing,         [ Links ]

Wilson R.P, (1978). Energy conservation options for residential water heaters, Journal on Energy, Vol. 3, Issue 2, April 1978, pp. 149-172.         [ Links ]



Received 12 August 2011
Revised 1 May 2012

Creative Commons License Todo el contenido de esta revista, excepto dónde está identificado, está bajo una Licencia Creative Commons