analysis of the influences of solar radiation and façade glazing ...

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1.2 Background and literature review 20 Yohanis and Norton (Yohanis, et al., 2000) revealed that the investigation of direct solar gain utilization in buildings can be properly carried out based on a zone-by-zone analysis. The base-case building (located Hemel Hempstead, England) was divided into fourteen volume subjects, called zones. The SERI-RES computer program was chosen for simulation tests. The usefulness of heating buildings is a function of the ratio. The calculation of solar gain as a function of the ratio of total solar to total loss (TS/TL) on a base of whole-building analysis can only lead to rough results. The absorption of solar radiation in buildings depends on the orientation and thermal mass of the building. This problem was investigated by the same authors (Yohanis, et al., 2002) based on a single-storey building with glazing areas equal to 42 % of the east and west elevations and located in London (latitude of 52°). A model of the base-case building was created in the thermal simulation code SERI-RES. Estimates indicated that for large thermal mass and for smaller values of the total solar to total loss, the impact of orientation is not significant. But for the small mass of the considered buildings, the percentage differences increase to 8 % for east, 10 % for west and 12 % for north orientations. Florides, with co-workers (Florides, et al., 2002), carried out a thermal response of modern houses taking into consideration ventilation, solar shading and the type of glazing, as well as the shape, orientation and thermal mass of the buildings. The heating and cooling loads were calculated with use of computer software TRNSYS and a typical meteorological year (TMY) for Nicosia, Cyprus. The considered modern house had a floor area of 196 m 2 and consisted of four external walls with a low conductance and low transmittance window glazing with area equal to 5.2 m 2 . The simulation results for the warm period indicated that night ventilation can reduce peak internal temperatures by 2°C, 3°C and 7°C for one, two and eleven air changes per hour, respectively. Moreover, nine air changes per hour can lead to a 7.7 % reduction (maximum value) in annual cooling load. The problem of controlling the solar heat gains in order to reduce the capacity of an air conditioning system was studied by Saleh (Saleh, et al., 2004). They proposed a horizontal rotation of glass windowpanes. The computer program was developed to determine the sun declination and limits of sunlight hours. It was found that the percentage of direct solar heat gain changes achievable by a rotation-angle magnitude of 30 0 and for east wall orientation equals to -11 % and 42 % for summer and winter solstice time, respectively. A novel glazing system with a rotatable frame for buildings located in climates where heating and cooling are required, was investigated by Etzion and Erell (Etzion, et al., 2000). Frame holds have transparent glazing and absorptive glazing with a low shading coefficient. Before a heating season, the glazing system rotates and the absorbing part is on the interior side. The experimental investigations for warm periods showed that the interior radiation for the reversible new glazing system and reference standard 3 mm transparent glazing were reduced to approximately 5 % and 37 % of exterior levels, respectively. For
1.2 Background and literature review 21 winter conditions, the solar radiation through the tested windows was identical to the standard window. Fissore and Fonseca (Fissore, et al., 2007) investigated the thermal behavior of an enclosed space with fenestration for temperate winter climates. Experiments were carried out for heating season conditions and during summer periods. An uncertainly analysis indicated that the most significant errors are generated from measurements of surfaces and air temperature. Errors connected with thermocouples and voltage measurement can be significant. The same authors (Fissore, et al., 2007) analyzed the thermal balance of a window in an office in climate conditions typical for Concepcion (Chile). One-year measurements of ambient and indoor parameters under simulation of various operation conditions showed that heat consumption for uncovered windows during clear winter days could be smaller about 50 % compared to a cloudy period. For autumn conditions, this value was reduced to 26.6 %. The Task 34/Annex 43 project of the International Energy Agency (IEA) included six experiments in an outdoor test cell in order to provide the necessary data for the validation of building energy simulation models and computer software (Manza, et al., 2006). The experimental facility was assembled with two identical cuboid shape test cells with removable façade elements. An air-water heat exchanger was used to control the air temperature inside guarded zones. DOE-2.1E, EnergyPlus, ESP-r and HELIOS building energy simulation computer programs were used for modelling the thermal behavior of the tested spaces. Experimental data, which are available on the Internet from www.empa.ch/ieatask34, can be a good base to investigate solar gains through transparent elements and can also be used to validate existing software for the energy analysis of buildings. The beam solar radiation incident on building fenestration can be controlled with holographic optical elements. This system was tested by James and Bahaj (James, et al., 2005) in modern, highly glazed office extensions with a low thermal mass at Southampton University (UK). The possible solutions of the solar control problem were tested based on the transient thermal simulation of the building structure with help of the computer code TRNSYS. The authors assumed that the HOE systems function at a 100 % diffraction efficiency but required alignment between incident direct radiation and the angle of the hologram. Moreover, the effects of glare and spectral dispersion may cause the unsuitable functioning of holographic elements. Coating with a spectrally selective layer on external walls can affect heat transfer. Prager and co-workers (Prager, et al., 2006) analyzed the influence of solar radiation and convection on the energy balance of a building based on test facilities in Freiburg (Germany). It was found that the considered IR radiative component reduces the heat demand to between 5 % and 15 % during the winter season. However, in summer time, the
Page 1 and 2: ANALYSIS OF THE INFLUENCES OF SOLAR
Page 3 and 4: than the inner air temperature. It
Page 5 and 6: 4.1 SUMMARY .......................
Page 7 and 8: Subscripts σ - Stefan-Boltzmann co
Page 9 and 10: 1.1 Introduction 9 Another problem,
Page 11 and 12: 1.2 Background and literature revie
Page 19: 1.2 Background and literature revie
Page 41 and 42: 2.1 Building energy simulation soft
Page 47 and 48: 2.2 Experimental research methods 4
Page 53 and 54: 3.1 Building description 53 Fig. 3.
Page 55 and 56: 3.1 Building description 55 All int
Page 57 and 58: 3.1 Building description 57 Case B5
Page 59 and 60: 3.1 Building description 59 Of cour
Page 61 and 62: 3.1 Building description 61 Outside
Page 63 and 64: 3.1 Building description 63 In orde
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3.3 Estimation of thermal energy ga
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3.4 Testing of a building indoor en
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36 34 32 30 28 26 24 22 20 18 36 34
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3,00 2,50 2,00 1,50 1,00 0,50 0,00
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3.5 Optimization of a solar domesti
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4.1 Summary 99 4 Summary and conclu
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4.2 Comments and conclusions 101 So
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4.3 Future research 103 of the annu
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References 105 Beausoleil-Morrison,
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References 107 Hendron, R., et al.
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References 109 Rees, S. and Haves,
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References 111 Yohanis, Y.G., et al
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Appendix 1 113 Fig. A1.1 VASATI 2.0
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Appendix 2 123 !-Generator IDFEdito
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Appendix 2 125 0.035, !- Conductivi
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Appendix 2 127 , !- Zone Inside Con
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Appendix 2 129 Discrete; !- Numeric
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Appendix 2 131 Fraction, !- Schedul
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Appendix 2 133 Air Conditioner:Wind
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Appendix 2 135 , !- Sensible Heat F
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Appendix 2 137 281, !- Lighting Lev
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Appendix 2 139 OG2 InfilTRATION, !-
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Appendix 2 141 OG3, !- Zone Name 16
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Appendix 2 143 0.004, !- Zone Heati
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Appendix 2 145 Zone15WindACAirInlet
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Appendix 2 147 0, !- Maximum Flow R
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Appendix 2 149 Zone16WindACOAMixer,
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Appendix 2 151 Zone 9 Outlet Node;
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Appendix 2 153 Stand Alone ERV 16,
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Appendix 2 155 ZoneHVAC:WindowAirCo
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Appendix 2 157 ZoneHVAC:Baseboard:C
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Appendix 2 159 Zone Control Type Sc
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Appendix 2 161 WindACPLFFPLR, !- Pa
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Appendix 2 163 Stand Alone ERV Supp
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Appendix 2 165 0.03001, !- Maximum
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Appendix 2 167 0.81, !- Sensible Ef
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Appendix 2 169 !- == ALL OBJECTS IN
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