Office for Environmental Programs - Theses

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    Are cool roofs worth it for Melbourne
    Whimpey, Bruce Gregory ( 2011)
    Roofs are important assets in the struggle to reduce the carbon footprint of buildings. Cool roof technology offers one way in which this can be tackled. The concept is being tested via the establishment of some sheds with cool roofs at the Burnley campus of Melbourne University. TRNSYS is being utilised in order to predict the thermal response of the test huts and those results are being compared against measured temperatures. A marked temperature decrease has been noted in the summer temperatures of the sheds with cool roof coatings
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    Can thermal mass be utilised to reduce greenhouse gas emissions from buildings in Melbourne?
    Whimpey, Bruce Gregory ( 2014)
    The motivations for this paper were a reduction in greenhouse gas emissions from Melbourne's buildings, a reduction in their utility costs and thermal comfort improvements within them. There are gaps in the literature regarding the use of thermal mass in Melbourne's buildings and the use of off peak electricity for heating. With this in mind, research questions arose that asked if thermal mass would produce a quantum leap in the performance of Melbourne's buildings and can off peak electricity be used to provide heating to those buildings and how does phase change material perform relative to more traditional forms of thermal mass? To find the answer to those questions, small test buildings (huts) of approximately one metre cubed size were made from cool room panels and were erected at Burnley campus. The huts were made air tight and water tight via the use of expandable foam and with a sheet of poly-carbonate sheeting that was placed above the cool room panel box sloping towards the front. A window of area 0.18 m2 was constructed in the south wall of the cubic boxes. The huts were each suspended above the ground on standard wooden pallets. Two of the huts had thermal mass within them in the form of PCM sheets and containers of water. The third building was empty as a control. Power cords were connected to the three huts so that heaters and incandescent floodlights could be used to provide heating to the huts, The setup was modelled in TRNSYS which allowed the experiment to be simulated across a full year. Measurements of the hut air dry-bulb temperatures were made with logtag devices suspended by string from the centre of the hut's roof. Thermocouple loggers were also used to record the temperature of the water and of the PCM lumps on the PCM sheets. The results showed that thermal mass made quite an impact on comfort levels in the buildings with reduced decrement factors and the rate of change of temperatures being experienced. The TRNSYS models produced results that predicted that this situation should apply across the year's seasons - this project only collected experimental data for the spring season. It is deduced from those results that if a building is not intermittently occupied, thermal mass can be used to reduce utility costs and greenhouse gas emissions from buildings whilst delivering an improvement in thermal comfort. This means that thermal mass is a good option in the construction of Melbourne's buildings with the PCM product surveyed being a good option for timber buildings in particular. Further research into the topic might include other material types and a subsequent consideration of their embodied energy. Also, research may be useful with buildings that are more realistic in size, work could be done to construct an acceptable PCM model and there could be further work in the use of off peak electricity for heating and cooling.