Solar facades for heating and cooling in buildings

The aim of this thesis is to study the energy performance of a building integrated heating and cooling system. The research objectives are to investigate the system operating characters, to develop mathematical models for the heating and cooling systems, to demonstrate the technologies experimentally, to identify the best designs for a combined system and to investigate the cost effectiveness of the system. The main components of the systems are the aluminium plate façade and the building wall behind it, these form a plenum between them and the air is then heated or cooled as it flows through this plenum. Mathematical models were developed based on the energy balance equations and solved by matrix inversion method. These models were then validated with experimental results. The experiments were carried out in the laboratory with a facade area of 2m2. Two designs of facade were tested, i.e. flat and transpired plates. Results showed that the transpired design gave better thermal performance; the system efficiency for the flat plate was only about 30%, whereas it was about 85% for the transpired plate. On the other hand, a cooling system with double plenums was found to be better than a single plenum. Thus, a transpired plate with two plenums was identified as the best design for space heating and cooling. The cooling efficiency was nearly 2.0 even at low solar radiation intensity. A simulation study was carried out by assuming a 40m2 of façade was installed on an office building in London. The yearly energy saving was estimated as 10,877kWh, which is equivalent to 5,874kgCO2/year of emission avoidance. The system is calculated to cost about £70/m2, and for a discount rate of 5% and 30 years of lifetime, the payback period for this system would be less than a years

Solar facades for heating and cooling in buildings

The aim of this thesis is to study the energy performance of a building integrated heating and cooling system. The research objectives are to investigate the system operating characters, to develop mathematical models for the heating and cooling systems, to demonstrate the technologies experimentally, to identify the best designs for a combined system and to investigate the cost effectiveness of the system. The main components of the systems are the aluminium plate façade and the building wall behind it, these form a plenum between them and the air is then heated or cooled as it flows through this plenum. Mathematical models were developed based on the energy balance equations and solved by matrix inversion method. These models were then validated with experimental results. The experiments were carried out in the laboratory with a facade area of 2m2. Two designs of facade were tested, i.e. flat and transpired plates. Results showed that the transpired design gave better thermal performance; the system efficiency for the flat plate was only about 30%, whereas it was about 85% for the transpired plate. On the other hand, a cooling system with double plenums was found to be better than a single plenum. Thus, a transpired plate with two plenums was identified as the best design for space heating and cooling. The cooling efficiency was nearly 2.0 even at low solar radiation intensity. A simulation study was carried out by assuming a 40m2 of façade was installed on an office building in London. The yearly energy saving was estimated as 10,877kWh, which is equivalent to 5,874kgCO2/year of emission avoidance. The system is calculated to cost about £70/m2, and for a discount rate of 5% and 30 years of lifetime, the payback period for this system would be less than a years

Thermal analysis of flat and transpired solar facades

Building integrated solar technologies is important not only to reduce energy consumption and carbon emissions but also to help to make the technologies more economically feasible and challenge the creativity of architects in designing buildings. In this paper, two types of solar facades for heating purposes were studied: flat and transpired aluminium plates. Mathematical models of the thermal performance of these plates were developed and verified through experiments. The thermal performances were then compared in terms of heat gains and losses under the same operational conditions. It is found that the transpired design is able to reduce heat losses and hence achieve better heat transfer: the efficiencies for the flat and transpired facades are about 30% and 80% respectively

Drying Kinetics and Drying Models of Terong Dayak (Solanum lasiocarpum)

Drying using a hot air chamber was tested on samples of terong dayak (Solanum lasiocarpum). Drying kinetics curves of drying S. lasiocarpum demonstrated that drying at 55oC and relative humidity of 10% were the optimum values for drying S. lasiocarpum, with the appropriate equations using the Page’s model drying equation MR = exp (-0.5494t1.4052) that produced 96.8% accuracy. According to the results which showed the highest average values of R2 and the lowest average values of MBE and RMSE, therefore it can be stated that the Page model could describe the drying characteristics of S. lasiocarpum in the drying process at a temperature of 55oC and relative humidity of 10%. Keywords: Drying kinetics, drying modeling, hot air chamber, S. lasiocarpum, terong daya

Mathematical Modeling of Belimbing Dayak Fruit (Baccaurea angulata) Influence of Different Drying Air Temperature

Drying using a hot air chamber was tested on samples of belimbing dayak fruit (Baccaurea angulata). The drying experiments were performed at various air temperature drying (40 to 50oC). Drying kinetics of belimbing dayak fruit were investigated and obtained. Ten drying models were compared with experiments data belimbing dayak fruit drying. A new model was introduced, which is an offset linear logarithmic (offset modified Page model). The fit quality of the models was evaluated using the coefficient of determination (R2), Root Mean Square Error (RMSE) and Sum of Squared Absolute Error (SSAE). The result showed that the new model was comparable with two or three-term exponential drying models. Keywords: B. angulata, belimbing dayak, drying kinetics, drying modeling, hot air chambe

Activation Energy of Thin-layer Drying Kinetics of Belimbing Dayak Fruit (Baccaurea angulata)

Drying using a hot air chamber was tested on samples of belimbing dayak (Baccaurea angulata). The drying experiments were performed at drying air temperature 40, 45 and 50°C, respectivly and at a constant relative humidity of 20% and constant air velocity of 1 m/s. The drying kinetics of B. angulata were investigated and obtained. The time required to dry B. angulata from an initial moisture content of about 89% (wb) to the final moisture content of around 8% (wb) was 13, 11.5 and 7 h at 45, 50 and 55°C of drying air temperature respectively. The effective moisture Diffusivity (Deff) of B. angulata increased from 1.99×10-9 to 3.71×10-9 m2 /s as the drying air temperature increased from 45 to 55°C. The activation energy of diffusion (Ea) was calculated about 54 kJ/mol. Keywords: Activation energy, B. angulata, belimbing dayak, drying kinetics, hot air chambe

Solar facades for heating and cooling in buildings

The aim of this thesis is to study the energy performance of a building integrated heating and cooling system. The research objectives are to investigate the system operating characters, to develop mathematical models for the heating and cooling systems, to demonstrate the technologies experimentally, to identify the best designs for a combined system and to investigate the cost effectiveness of the system. The main components of the systems are the aluminium plate façade and the building wall behind it, these form a plenum between them and the air is then heated or cooled as it flows through this plenum. Mathematical models were developed based on the energy balance equations and solved by matrix inversion method. These models were then validated with experimental results. The experiments were carried out in the laboratory with a facade area of 2m2. Two designs of facade were tested, i.e. flat and transpired plates. Results showed that the transpired design gave better thermal performance; the system efficiency for the flat plate was only about 30%, whereas it was about 85% for the transpired plate. On the other hand, a cooling system with double plenums was found to be better than a single plenum. Thus, a transpired plate with two plenums was identified as the best design for space heating and cooling. The cooling efficiency was nearly 2.0 even at low solar radiation intensity. A simulation study was carried out by assuming a 40m2 of façade was installed on an office building in London. The yearly energy saving was estimated as 10,877kWh, which is equivalent to 5,874kgCO2/year of emission avoidance. The system is calculated to cost about £70/m2, and for a discount rate of 5% and 30 years of lifetime, the payback period for this system would be less than a years.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Thermal Effectiveness Enhancement of Autoclaved Aerated Concrete Wall with PCM-Contained Conical Holes to Reduce the Cooling Load

This work investigates and improves the thermal dynamics of autoclaved aerated concrete (AAC) wall containing phase change material (PCM). The PCM is paraffin wax loaded into conical holes drilled into the AAC. Filled AAC with three different numbers of PCM-filled holes (2, 3, and 4 conical holes, which are designated as AAC-2H, AAC-3H, and AAC-4H, respectively) as well as the unfilled original AAC were both tested under two different conditions: indoors (with controlled temperature) and outdoors (with actual weather). For the indoor experiment, a heater was used as a thermal source and set up to maintain the testing temperature at one of three levels: 40 °C, 50 °C, or 60 °C. The wall temperature was then measured on the surface with each horizontally-positioned wall as well as four different positions at various depths below the surface of the wall. It was found that AAC-4H was the optimum condition, which can produce outstandingly a time lag of approximately 27%, reduce a decrement factor of approximately 31%, and also decrease the room temperature. This reached approximately 9% when compared with that of ordinary AAC at the controlled testing temperature of 60 °C. All samples were further tested in actual weather to confirm the thermal performances of AAC-4H. Thermal effectiveness of AAC-4H was improved by extending approximately a 14.3% time lag, which reduces approximately a 4.3% decrement factor and achieving approximately 5% lower room temperature when compared with ordinary AAC

Sustainable Development Goals through Energy cooperation in ASEAN

The ASEAN primary energy demand to grow by an average of 3.4% per year from 627 to reach 1,450 million tons of oil equivalent by 2040. In the alignment to accelerating the energy transition through the ASEAN, the region is aiming to reach 23% of RE in the total primary energy supply (TPES). With the five-year remaining, ASEAN has a lot opportunity to accelerate the effort. This research presents overview of the shaping of the renewables and low-carbon power utilisation which has been in the action plan to optimise effective and efficient power utilisation. It will be presented in the study report, the alignment of low-carbon society and renewable energy promotion in ASEAN has been in great progress considering its attempt to improve all power utilisation lineage

The ASEAN climate and energy paradox

This article carries out a multisectoral qualitative analysis (MSQA) and policy integration analysis of six sectors important for climate mitigation in Southeast Asia in order to assess the status of the climate-energy nexus in the region. It concludes that Southeast Asia will be heavily affected by climate change but the mitigation efforts of the member states of the Association of Southeast Asian Nations (ASEAN) are incommensurate with the threat they face. Their nationally determined contributions under the Paris Agreement are modest, they have a low proportion of renewable energy in their energy mixes, a modest target for raising the share of renewable energy and they are not likely to reach this target. The ASEAN countries have also been slow to adopt electric vehicles and to accede to the International Renewable Energy Agency (IRENA), while continuing to burn their forests, channel subsidies to fossil fuels and invest in new coal power plants. If ASEAN accelerated decarbonization, it could seize business opportunities, secure its standing in the international political system and climate justice discussions, and increase its chances of reaching the United Nations Sustainable Development Goals (SDGs)