Infra-red thermal imaging

Подпись: Fig. 9. Thermal images of solar heating systems.

An infra-red camera was used to check for any defects in the thermal insulation around the tank or any other hidden thermal losses. It was found that there were no losses except from one end of the solar tank, where the electric booster is situated, as shown in Figure 9. Because of that, no insulation is usually placed in that area but just a plastic cover. Otherwise, the insulation around the tank was homogenous and no hot spots were identified.

4.2 Statistics of days with insufficient hot water

Data analysis showed that the number of days with insufficient hot water and that would have required boosting by the electric back-up heating element, ranged between 5 days for a conservative user to 15

or more days for an average user. One has to bear in mind the parameters of this study i. e. 150 litres evacuated-tube solar heating systems, being utilised by couples.

5. Conclusions

The results of this study showed that sizing solar systems should take into consideration, not only the number of persons in the residence, but also their washing habits (showers or baths), their specific requirements (connection of solar hot water to kitchen, washing machine, etc..), the number of days for hot water storage, as well as the inclusion of the FUPF, which caters for any future increase in hot water demand.

Another important conclusion that was reached is that savings do not come automatically with installation of a solar system. In fact, misuse of the solar heating system could at times, lead to higher electricity bills. As a result of close interaction with the users, it was concluded that there was a strong deficiency in the provision of information and education on solar heating systems, even from the side of the installers. It is recommended that a national information campaign be made for the different entities concerned (domestic users, suppliers, installers, large-users, etc.). Only then would misconceptions and doubts be eliminated and more citizens opt for solar heating.

It is also recommended that dealers should start providing instruction and troubleshooting manuals, be more accessible and quick to respond to after-sales services and where possible, offer maintenance contracts. Only then would customer satisfaction be improved and more solar systems be installed.

6. Acknowledgements

Our gratitude goes to the Housing Authority, the Housing Construction and Maintenance Department and to all apartment owners, who supported us during this study.

References

[1] National Statistics Office (2007), Results of the National Census 2005, http://www. nso. gov. mt/statdoc/document file. aspx? id=20961, accessed on 30th June 2008.

[2] R. Farrugia, E. Mallia, M. Fsadni & C. Yousif (2006) Barriers and Incentives for the Widespread Application of Renewable Energy in Malta, Proceedings of the World Renewable Energy Congress — IX, 19th-25th August 2006, Florence, Italy.

[3] V. Buhagiar, F. Camilleri, J. Cilia, R. Piscopo, C. Yousif (2002), Recommendations for Energy Efficient Housing at Tal-Ftieh, Birkirkara, April 2002, unpublished report to the Housing Authority, Floriana, Malta.

[4] The Housing Authority (2004), The Policies of the Housing Authority, Energy Saving, Article 5, http://www. housingauthoritv. com. mt/Publications/the policies. pdf, accessed on 30th June 2008.

[5] The Malta Environment and Planning Authority (2007), Development Control Policy and Design Guidance 2007, Part 13, ISBN 978-99932-83-68-3.

[6] C. Fernandez Vazquez (2008), Performance Analysis of Water-in-Glass Evacuated-Tube Solar Heating Systems at a Housing Project in Malta, unpublished final-year dissertation, Institute for Energy Technology, University of Malta, Malta, in collaboration with Valladolid University, Spain, under the Erasmus Student Exchange European Programme 2007/08..

[7] Enemalta Corporation, http://www. enemalta. com. mt/page. asp? p=926&l=1, accessed 30 July 2008.