The performance of split and integrated types of air-source heat pump water heaters in South Africa

Authors

DOI:

https://doi.org/10.17159/2413-3051/2018/v29i2a4358

Keywords:

coefficient of performance; vapour compression refrigeration cycle; renewable energy technologies

Abstract

Renewable energy technologies that can provide optimum and cost-effective energy savings to mitigate global warming, energy crisis and to achieve energy efficiency continue to be of paramount importance. The present study focused on identifying critical parameters such as the volume of hot water drawn off; ambient temperature; relative humidity; refrigerant temperatures at the inlet and outlet of the compressor and condenser; and deterministic quantities such as time used, power consumption and coefficient of performance (COP) as indicators to benchmark the performance of both the split and integrated types of air-source heat pump (ASHP) water heaters. The basis for analysis was on two predominant scenarios: first-hour heating rating and the heating cycle due to controlled volume of hot water drawn-off wherein both the integrated and split types ASHP water heaters experienced vapour compression refrigeration cycles. A data acquisition system was constructed and implemented to monitor the performance of both systems. The results obtained during summer season showed that, under the scenario of 150 L hot water withdrawal, the average COP of the systems was 3.18 and 2.85 for the split and integrated types respectively. The average power consumed was 1.29 (split type) and 0.85 kW (integrated type). The times of operation were 84 minutes (split type) and 138 minutes (integrated type).

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Author Biographies

  • Stephen Loh Tangwe, Fort Hare Institute of Technology, University of Fort Hare, Alice, South Africa

    Stephen Tangwe holds a B.Eng. (Hons) and M. Eng degree in Electrical Engineering from AIU, Honolulu, Hawaii. He is an IEE Graduate student and also an IEE Power and Energy society member. At present, he is a graduate student member in the South Africa Institute of Electrical Engineers and his an adhoc Eskom M&V Engineer with the university of Fort Hare team. He is also an energy efficiency research candidate with Fort Hare Institute of Technology and a MATLAB application Engineer. He is a seasoned author and reviewer in many accredited peer review journals and conference proceedings.

    Tel:0783076922; Email: stangwe@ufh.ac.za

  • Michael Simon, Fort Hare Institute of Technology, University of Fort Hare

    Michael Simon holds a PhD degree in Physics from the University of Fort Hare. He is presently the university of Fort Hare Energy Manager and Head of the Energy Efficiency Group in FHIT. He is also a certified Eskom M&V professional and Team leader of the Eskom M & V team of the university of Fort Hare. He is a Photo Voltaic & an Energy Efficiency specialist.

  • Russel Mhundwa, Fort Hare Institute of Technology, University of Fort Hare

    Russel Mhundwa holds a Ph.D. degree in Physics from the University of Fort Hare. He is an ad-hoc Eskom M&V Technician with the UFH team. He is a certified Professional Physicist (Pr.Phys), a member of SAIP and SAEE. He is also a renewable energy specialist.

References

Aprea, C., Greco, A. and Rosato, A. 2008. Comparison of R407C A heat transfer coefficient and pressure drops during flowing boiling in a horizontal smooth tube. Energy Conversion and Management 49(6): 1629-1636.

https://doi.org/10.1016/j.enconman.2007.11.003

Bodzin, S. 1997. Air-to-water heat pumps for the home. Home Energy, 14(4).

Bryson, D. 2011. Eskom key reason South Africa is a big polluter. Association Press, 24, 679-684.

De Swardt, C.A. and Meyer, J.P. 2001. A performance comparison between an air-source and a ground-source reversible heat pump. International Journal of Energy Research 25(10): 899-910.

https://doi.org/10.1002/er.730

Huang, B.J. and Lin, F.H., 1997. A compact and fast temperature-response heat pump water heater. In ASME 1997 Turbo Asia Conference, V001T13A002-V001T13A002. American Society of Mechanical Engineers.

https://doi.org/10.1115/97-AA-026

Levins, W.P. 1982. Estimated seasonal performance of a heat pump water heater including effects of climate and in-house location (No. ORNL/CON-81). Oak Ridge National Lab., TN (USA).

Meyer, J.P. and Tshimankinda, M. 1998. Domestic hot water consumption in South African townhouses. Energy Conversion and Management 39(7): 679-684.

https://doi.org/10.1016/S0196-8904(97)00048-4

Morrison, G.L., Anderson, T. and Behnia, M. 2004. Seasonal performance rating of heat pump water heaters. Solar Energy 76(1): 147-152.

https://doi.org/10.1016/j.solener.2003.08.007

Tangwe, S., Simon, M. and Meyer, E. 2016. Design of a heat pump water heater performance monitoring system: To determine performance of a split type system. Engineering Journal of Technology and Design14(4):739-751.

https://doi.org/10.1108/JEDT-08-2014-0055

Tangwe, S., Simon, M. and Meyer, E. 2014. Mathematical modelling and simulation application to visualize the performance of retrofit heat pump water heater under first-hour heating rating. Renewable Energy 72: 203-211.

https://doi.org/10.1016/j.renene.2014.07.011

Tangwe, S., Simon, M. and Meyer, E., 2014. Analytical evaluation of the energy losses of an air source heat pump water heater: A retrofit type. Journal of Energy and Power Engineering 8(7): 1251-1257.

Tangwe, S., Simon, M., Meyer, E.L., Mwampheli, S. and Makaka, G., 2015. Performance optimization of an air source heat pump water heater using mathematical modelling. Journal of Energy in Southern Africa 26(1): 96-105

Van Eeden, S.J., Jacobsz, S.W., Rust, M. and Rust, E., 2016. Electricity generation as a beneficial post-closure land use option for a dormant tailings storage facility. Journal of the South African Institution of Civil Engineering 58(1): 53-61.

https://doi.org/10.17159/2309-8775/2016/v58n1a6

Ye, X., Xia, X. and Zhang J. 2012. Residential heat pump rebate programme. Energy efficiency measurement and verification practices, Ed. Xia, X. and Zhang, J. Media in Africa (Pty) Ltd, Unit G, Castle Walk Corporate Park.

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Published

2018-06-22

Issue

Vol. 29 No. 2 (2018): Journal of Energy in Southern Africa. May

Section

Articles

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Copyright (c) 2018 Stephen Loh Tangwe, Michael Simon, Russel Mhundwa

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This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

How to Cite

The performance of split and integrated types of air-source heat pump water heaters in South Africa. (2018). Journal of Energy in Southern Africa, 29(2), 12-20. https://doi.org/10.17159/2413-3051/2018/v29i2a4358