The motivation behind building homes is ultimately to protect ourselves from adverse climatic conditions and to obtain a neutral thermal comfort level. However, the local built environment does a very bad job at dealing with heat in summer and cold in winter – pushing us to heavily rely on air conditioners and heaters.
Recent research on a project headed by the Institute of Sustainable Energy at the University of Malta provides scientific evidence that it is possible to convert your existing home into a zero energy and thermally comfortable environment. We are not talking about new building designs and filling a roof with solar panels. The study focuses on rectifying typical sub-par existing construction design and practices.
The research conducted by Stefan De Marco was based on an apartment in Birkirkara. The energy-saving measures have been fine-tuned for Malta’s climatic conditions and building fabrics. Various relevant aspects such as temperature and humidity were monitored indoors for 12 months. The results showed that passive measures, such as natural ventilation in summer and solar gains in winter, combined with the energy-saving measures, kept the place comfortable through all the seasons.
Such energy-saving retrofit measures consisted of external roof and wall insulation, adjustable louvres, sealing of all ventilators (contrary to the norm) and double action PVC double-glazed windows. The level of customisation required was achieved by the creation of a novel model that is able to guide the retrofitting process based on heat transfer principles for any specific dwelling.
The applied measures only failed to satisfy standard comfort levels for a total of 25 days over a whole year. As a matter of fact, a fan was only needed for three weeks in August, and for some of the winter season, a fleecy top is needed – as opposed to a long-sleeved top for the rest of the colder periods. Subjective tests reported that the middle of February felt more like spring, while our hot summer was bearable with just a light breeze or a fan.
Moreover, the initial costs of retrofit measures pay off after 15 years. This analysis shows that energy efficient dwellings are indeed a possibility in our local climate if retrofitted with adequate and customised measures.
For more details about this project, the full study and results are presented in the University of Malta dissertation ‘Retrofitting a Mediterranean dwelling into a thermally comfortable minimum energy home: A case study in Malta’.
Did you know…
• A compact fluorescent light bulb uses 75 per cent less energy than a regular bulb and it can last up to four years.
• Every time you open the refrigerator door, up to 30 per cent of the cold air can escape.
• A screen saver actually wastes energy and it can also prevent your computer from going to sleep, which is an important energy-saving feature.
• A hot water faucet that leaks one drop per second can add up to 165 gallons a month. That’s more than one person uses in two weeks.
For more trivia: www.um.edu.mt/think
Sound bites
• Scientists have developed solar cells 100 times thinner than a human hair. Scientists in South Korea have developed solar cells thin enough they can be bent around a pencil. The cells could help usher in the use of solar energy in small portable gadgets where space is at a premium. Solar cells are commonly used as power sources in several types of large electronics, but their use on consumer items has been limited.
http://www.sciencealert.com/scientists-have-developed-solar-cells-100-times-thinner-than-a-human-hair
• Scientists are developing graphene solar panels that generate energy when it rains. Key to the process is graphene – a wonder material. Raindrops, not made of pure water, can be harnessed by chemical reaction with graphene and used to generate electricity. Early tests with salty water (rain) allowed the generation of hundreds of microvolts, achieving a 6.53 per cent solar-to-electric conversion efficiency.
http://www.sciencealert.com/how-graphene-could-help-solar-panels-produce-energy-when-it-s-raining