ZEMCH 2019 International Conference Proceedings April.2020 | Page 289
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Diffuse Horizontal Solar Radiation Wh/m²
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Figure 3. Average monthly solar radiation and Sky cover for Melbourne. RMY statistics
The above indicates that during winter, which lasts for over half a year, solar radiation is not a
dependable heat renewable heat source. Therefore, it is not worth to invest in expensive evacuated
tubes and a wood burner will be installed. Nevertheless, an inexpensive flat‐belt type solar collector
will be tested without and with glazing.
2.2b Hot water for RC by wood burner.
Trees grow by absorbing greenhouse gas elements from the environment, thus wood is a store of
renewable energy. Fruit trees must be pruned yearly, and twigs makes it easier to kindle a wood fire to
warm up the firebox for complete combustion of wood before the combusted gases go through the
chimney. Some wood stove makers recommend 15 minutes before logs are burnt, and moisture
indicators are available to check that wood is dry enough. Dampers can be used to ensure intake air
and flue are just right for non‐polluting exhaust from the chimney. Wood can thus be a clean renewable
energy source.
3. Materials and Method
The building envelope of this building is made of metallic‐clad polystyrene panels that gives this
building the mandatory 6‐energy stars when rated by a software that satisfies the Nationwide House
Energy Rating Scheme (NatHERS). It is 200mm thick at the roof (R‐value of 5m2.K/W), 150mm thick (R
value of 3.75m2.K/W) for the walls and 100mm thick for the floor.
3.1 The HR‐floor – heat indoors to 15°C by 50m deep vertical ground heat exchanger.
The hydronic floor of the 3mW x 6mL building is 13mm diameter irrigation tubing spaced at
100mm in 45mm reinforced concrete cast above the 100mm thick metallic‐clad polystyrene laid on
ground.
The U‐tube in 50m‐deep VGHE conditions water 15.5±1°C and is circulated to the HR inside the
concrete floor, Ooi et al (2016) pointed out that, based on VDI 4640 German Guidelines for Ground
Coupled Heat Pumps and the soil conditions at the Melbourne building, the power from each VGHE
would be 2.4 to 2.8KW. The floor area of the conditioned zones in the Melbourne building is 30m2; thus
one VGHE would give a power of about 90W/m2, and this is the range of flux density given by
www.healthyheating.com (2019). For cooling, Jeong et al’s simulated results shows a maximum total
load of 57W/m2. Thus, one VGHE should be able to supply enough heat and coldness for the Melbourne
experimental house.
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