Verification of the Performance of a Vertical Ground Heat Exchanger Applied to a Test House in Melbourne, Australia
The ground heat exchanger is traditionally used as a heat source or sink for the heat pump that raises the temperature of water to about 50 °C to heat houses. However, in winter, the heating thermostat (temperature at which heating begins) in the Australian Nationwide House Energy Rating Scheme (Nat...
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| Format: | Article |
| Language: | English |
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MDPI AG
2017-10-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/10/10/1558 |
| _version_ | 1798041474364866560 |
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| author | Koon Beng Ooi Masa Noguchi |
| author_facet | Koon Beng Ooi Masa Noguchi |
| author_sort | Koon Beng Ooi |
| collection | DOAJ |
| description | The ground heat exchanger is traditionally used as a heat source or sink for the heat pump that raises the temperature of water to about 50 °C to heat houses. However, in winter, the heating thermostat (temperature at which heating begins) in the Australian Nationwide House Energy Rating Scheme (NatHERS) is only 20 °C during daytime and 15 °C at night. In South-East Melbourne, the temperature at the bottom of a 50-meter-deep borehole has been recorded with an Emerson™ recorder at 17 °C. Melbourne has an annual average temperature of 15 °C, so the ground temperature increases by 2 °C per 50-m depth. A linear projection gives 23 °C at 200-m of depth, and as the average undisturbed temperature of the ground for a 400-m-deep vertical ground heat exchanger (VGHE). This study, by simulation and experimentation, aims to verify that the circulation of water in the VGHE’s U-tube to low-temperature radiators (LTRs) could heat a house to thermal comfort. A literature review is included in the introduction. A simulation, using a model of a 60-m2 experimental house, shows that the daytime circulation of water in this VGHE/LTR-on-opposite-walls system during the 8-month cold half of the year, heats the indoors to NatHERS settings. Simulation for the cold half shows that this VGHE-LTR system could cool the indoors. Instead, a fan creating a cooling sensation of up to 4 °C is used so that the VGHE is available for the regeneration of heat extracted from the ground during the cold portion. Simulations for this hot portion show that a 3.4-m2 flat plate solar collector can collect more than twice the heat extracted from the ground in the cold portion. Thus, it can thus replenish the ground heat extracted for houses double the size of this 60-m2 experimental house. Therefore, ground heat is sustainable for family-size homes. Since no heat pump is used, the cost of VGHE-LTR systems could be comparable to systems using the ground source heat pump. Water circulation pumps and fans require low power that can be supplied by photovoltaic thermal (PVT). The EnergyPlus™ v8.7 object modeling the PVT requires user-defined efficiencies, so a PVT will be tested in the experimental house. |
| first_indexed | 2024-04-11T22:22:01Z |
| format | Article |
| id | doaj.art-8a959bbc096a450a9fc370a162f45dc7 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-11T22:22:01Z |
| publishDate | 2017-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-8a959bbc096a450a9fc370a162f45dc72022-12-22T04:00:02ZengMDPI AGEnergies1996-10732017-10-011010155810.3390/en10101558en10101558Verification of the Performance of a Vertical Ground Heat Exchanger Applied to a Test House in Melbourne, AustraliaKoon Beng Ooi0Masa Noguchi1Faculty of Architecture, Building and Planning, Melbourne School of Design, The University of Melbourne, Buildings 133, Parkville, VIC 3010, AustraliaFaculty of Architecture, Building and Planning, Melbourne School of Design, The University of Melbourne, Buildings 133, Parkville, VIC 3010, AustraliaThe ground heat exchanger is traditionally used as a heat source or sink for the heat pump that raises the temperature of water to about 50 °C to heat houses. However, in winter, the heating thermostat (temperature at which heating begins) in the Australian Nationwide House Energy Rating Scheme (NatHERS) is only 20 °C during daytime and 15 °C at night. In South-East Melbourne, the temperature at the bottom of a 50-meter-deep borehole has been recorded with an Emerson™ recorder at 17 °C. Melbourne has an annual average temperature of 15 °C, so the ground temperature increases by 2 °C per 50-m depth. A linear projection gives 23 °C at 200-m of depth, and as the average undisturbed temperature of the ground for a 400-m-deep vertical ground heat exchanger (VGHE). This study, by simulation and experimentation, aims to verify that the circulation of water in the VGHE’s U-tube to low-temperature radiators (LTRs) could heat a house to thermal comfort. A literature review is included in the introduction. A simulation, using a model of a 60-m2 experimental house, shows that the daytime circulation of water in this VGHE/LTR-on-opposite-walls system during the 8-month cold half of the year, heats the indoors to NatHERS settings. Simulation for the cold half shows that this VGHE-LTR system could cool the indoors. Instead, a fan creating a cooling sensation of up to 4 °C is used so that the VGHE is available for the regeneration of heat extracted from the ground during the cold portion. Simulations for this hot portion show that a 3.4-m2 flat plate solar collector can collect more than twice the heat extracted from the ground in the cold portion. Thus, it can thus replenish the ground heat extracted for houses double the size of this 60-m2 experimental house. Therefore, ground heat is sustainable for family-size homes. Since no heat pump is used, the cost of VGHE-LTR systems could be comparable to systems using the ground source heat pump. Water circulation pumps and fans require low power that can be supplied by photovoltaic thermal (PVT). The EnergyPlus™ v8.7 object modeling the PVT requires user-defined efficiencies, so a PVT will be tested in the experimental house.https://www.mdpi.com/1996-1073/10/10/1558vertical ground-heat exchangerlow-temperature radiatorsustainable ground heattest house |
| spellingShingle | Koon Beng Ooi Masa Noguchi Verification of the Performance of a Vertical Ground Heat Exchanger Applied to a Test House in Melbourne, Australia Energies vertical ground-heat exchanger low-temperature radiator sustainable ground heat test house |
| title | Verification of the Performance of a Vertical Ground Heat Exchanger Applied to a Test House in Melbourne, Australia |
| title_full | Verification of the Performance of a Vertical Ground Heat Exchanger Applied to a Test House in Melbourne, Australia |
| title_fullStr | Verification of the Performance of a Vertical Ground Heat Exchanger Applied to a Test House in Melbourne, Australia |
| title_full_unstemmed | Verification of the Performance of a Vertical Ground Heat Exchanger Applied to a Test House in Melbourne, Australia |
| title_short | Verification of the Performance of a Vertical Ground Heat Exchanger Applied to a Test House in Melbourne, Australia |
| title_sort | verification of the performance of a vertical ground heat exchanger applied to a test house in melbourne australia |
| topic | vertical ground-heat exchanger low-temperature radiator sustainable ground heat test house |
| url | https://www.mdpi.com/1996-1073/10/10/1558 |
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