Lisø PhD Dissertation Manuscript - NTNU

More documents

Recommendations

Info

interesting to compare those results with our own for these four stations. Driving rain numbers from Hoppestad for Oslo, Bergen, Trondheim and Tromsø are shown in Table 4. Note that the built environment around the stations in the late 1940s was likelyto be significantlydifferent than today, and the Bergen and Trondheim observing stations in Hoppestad were not in exactlythe same locations in these cities as the observations used in this study. Some differences are therefore to be expected. For comparison with our values, it is appropriate to use the wall indexes (I y‘s) from 901, 1801, 2701 and 3601 to represent driving rain from the east, south, west and north, respectively. The annual driving rain totals from 1946 to 1950 (in mm/yr) shown in Table 4 are roughlysimilar (at about 500 mm/yr) for Oslo, Trondheim and Tromsø, with approximately four times as much in Bergen (at just under 2100 mm/yr). With the exception of Oslo, our values (obtained by summing the four directional values in each row) are somewhat higher than Hoppestad’s. We must be cautious, however, in trying to draw any firm conclusions about absolute driving rain totals derived from these methods at anygiven station. It is the relative magnitudes of driving rain values versus direction at and between stations that are relevant in this comparison. The relative magnitudes between stations shown in Table 4, then, could suggest that Oslo has comparativelyless total annual driving rain than is implied byHoppestad’s results. The relative magnitudes for total annual driving rain at Bergen, Trondheim and Tromsø are, however, quite similar in both studies. Furthermore, the directional dependence at Oslo is also verysimilar in both cases, with perhaps a slightlylarger component from the south in our work. For Bergen, the 1974–2003 data yielded a relatively greater contribution from the east and less from the west than is found in Hoppestad. For Trondheim and Tromsø, the relative directional dependences were qualitativelyverysimilar in the two studies. 5. Recommendations for further work One important goal of future work is to determine how differences in free wind-driven rain loads affect ARTICLE IN PRESS J.P. Rydock et al. / Building and Environment 40 (2005) 1450–1458 1457 Table 4 Driving rain values (in mm/yr) from Hoppestad (1955) compared against driving rain wall indexes, I y (mm/yr), for Oslo, Bergen, Trondheim and Tromsø for the analysis period 1974–2003 (in italics) Location Annual driving rain bydirection Total annual driving rain North I 360 East I 90 South I 180 West I 270 Oslo 163 153 163 149 116 142 47 39 489 (483) Bergen 157 210 120 772 1129 1328 688 323 2094 (2633) Trondheim 84 75 53 81 91 140 301 417 529 (713) Tromsø 51 68 22 30 202 349 174 277 449 (724) moisture uptake in walls with ventilated wooden cladding. This is a necessaryelement in incorporating a driving rain wall index into design guidelines for buildings in Norway. Research to address this question is currentlyin progress at NBI/NTNU’s experimental building site in Trondheim. Data on driving rain and moisture uptake are obtained from several instrumented test walls with different ventilated wooden cladding configurations. An automated weather station and driving rain gauge provide supporting weather data. A second goal of future work is to develop simple algorithms for assessing how local topographical characteristics, especiallyin hillyor mountainous coastal terrain, alter driving rain exposures determined from observational data at weather stations. This is an important element in putting into practice use of regional driving rain information at specific building sites awayfrom the locations where the data are gathered. A third goal of future work is to use the method to evaluate changes in driving rain loads due to climate change under global warming. In order to do this, we must incorporate data from climate change scenarios into the methodology. This paper is a part of the NBI Research & Development programme ‘‘Climate 2000’’ [8,9]. An important aspect of the programme will be the preparation of a thorough overview of the relevant climatic loads that should be taken into account during the planning, design, execution, management, operation and maintenance of the built environment. The ‘‘robustness’’ of the Norwegian building stock will also be addressed as part of the programme, including the development of methods for classifying different climatic parameters and their impact on building enclosure performance. 6. Conclusion The principal advantages with the presented method are that the angular distributions of driving rain loads obtained are high resolution in terms of wind direction and that the results are based on long-term series of
1458 climate data that are readilyavailable. Where Hoppestad yielded driving rain intensities in only four principal directions (north, south, east and west), the method described here, with 36 directions, gives a much more detailed picture of the directional dependence of winddriven rain at a weather station. And where the Hoppestad results were based on only5 years of data, driving rain indexes presented in this paper are from 30 years of synoptic observations representing the most recent climate. As automated weather stations recording hourly values of precipitation and wind are becoming increasinglycommon in Norway, the abilityto determine driving rain wall indexes on a national scale using ISO- 15927-3 from long-term series of weather records will become a possibilityonlyin the decades to come. In the meantime, the methodologypresented in this paper provides a wayforward, bridging the gap between Hoppestad and an international standard that is, at present, not amenable to use in Norway. Acknowledgements This paper has been written within the ongoing NBI Research & Development programme ‘‘Climate 2000— Building constructions in a more severe climate’’ (2000–2006), strategic institute project ‘‘Impact of climate change on the built environment’’. The authors gratefullyacknowledge all our construction industry ARTICLE IN PRESS J.P. Rydock et al. / Building and Environment 40 (2005) 1450–1458 partners and the Research Council of Norway. A special thanks to Tore Kvande for valuable comments on the text. References [1] Jelle BP, Lisø KR. Slagregn—klimadata og grunnlag for beregninger (Driving rain—weather data and calculation methods, in Norwegian). NBI Project Report 344. Oslo: Norwegian Building Research Institute; 2003. [2] Hoppestad S. Slagregn i Norge (Driving rain in Norway, in Norwegian). NBI Report 13. Oslo: Norwegian Building Research Institute; 1955. [3] ISO 15927-3, Hygrothermal performance of buildings, part 3: calculation of a driving rain index for vertical surfaces from hourly wind and rain data. European Committee for Standardization 2003 (under approval). [4] Fazio P, Mallidi SR, Zhu D. A quantitative studyfor the measurement of driving rain exposure in the Montréal region. Building and Environment 1995;30(1):1–11. [5] WMO Publication 306, Manual on Codes, International Codes. vol. I. Geneva: World Meteorological Organization. [6] LacyRE, Shellard HC. An index of driving rain. The Meteorological Magazine 1962;91(1080):177–84. [7] LacyRE. Driving rain maps and the onslaught of rain on buildings. Proceedings of RILEM/CIB symposium on moisture problems in buildings. Helsinki, 1965. [8] Lisø KR, Kvande T, et al. Climate 2000—Building constructions in a more severe climate—Programme 2000–2006, Programme Description, NBI Report O10210-99. Oslo: Norwegian Building Research Institute; 2004. [9] Lisø KR, Aandahl G, Eriksen S, Alfsen KH. Preparing for climate change impacts in Norway’s built environment. Building Research & Information 2003;31(3–4):200–9.
Page 1 and 2:
Building envelope performance asses
Page 3 and 4:
Lisø, K.R./ Building envelope perf
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
BUILDING RESEARCH &INFORMATION (200
Page 43 and 44:
LisÖ et al. on how to cope with an
Page 45 and 46:
LisÖ et al. the exposure to contin
Page 47 and 48:
LisÖ et al. business premises. The
Page 49 and 50:
LisÖ et al. construction industry
Page 51 and 52:
Research in Building Physics, Carme
Page 53 and 54:
4 CLIMATE CHANGE SCENARIOS FOR NORW
Page 55 and 56:
with large amounts of precipitation
Page 57 and 58:
will most likely be worse, even wit
Page 59:
Graves, H.M. & Phillipson, M.C. 200
Page 62 and 63:
766 Nordvik and Lisø The topic of
Page 64 and 65:
768 Nordvik and Lisø into the futu
Page 66 and 67:
770 Nordvik and Lisø climate chang
Page 68 and 69:
772 Nordvik and Lisø 0 Â Â = p d
Page 70 and 71:
774 Nordvik and Lisø probably to a
Page 73 and 74:
BUILDING RESEARCH &INFORMATION (200
Page 75 and 76:
cost of repairing process-induced b
Page 77 and 78:
change in quality (Mehus et al., 20
Page 79 and 80:
on the impacts of different climati
Page 81 and 82:
different strategies: risk-based, p
Page 83 and 84:
Page 85 and 86:
Learning from experience - an analy
Page 87 and 88:
An important aspect of the programm
Page 89 and 90:
Concrete walls 32 % LECA masonry 10
Page 91 and 92:
construction industry, and academic
Page 93 and 94:
BUILDING RESEARCH &INFORMATION (JAN
Page 95 and 96:
greater variations (Lisø et al., 2
Page 97 and 98:
Typical problem areas and recommend
Page 99 and 100:
Figure 3b Recommended design of win
Page 101 and 102:
Figure 7 Example showing the recomm
Page 103 and 104:
Figure 11a Poor solution for a £as
Page 105 and 106:
Acknowledgements This paper was wri
Page 107 and 108:
Climate adapted design of masonry s
Page 109 and 110:
2. Masonry defects in Norway 2.1. S
Page 111 and 112:
Fig. 2. Example illustrations of th
Page 113 and 114: The presented results are in good a
Page 115 and 116: appropriate in a more severe type o
Page 117 and 118: screen in a two-stage weatherproofi
Page 119 and 120: INCREASED SNOW LOADS AND WIND ACTIO
Page 121 and 122: The hurricane (Beaufort number 12)
Page 123 and 124: The extensive revisions of the code
Page 125 and 126: The number of buildings investigate
Page 127 and 128: As is apparent from the values in t
Page 129 and 130: climate change is now dominated by
Page 131: TABLE 3. Summary of findings Struct
Page 134 and 135: Lisø, K.R./ Building envelope perf
Page 136 and 137: temperature of -4°C or less. See F
Page 138 and 139: Today, frost resistance of brick, c
Page 140 and 141: degree of saturation, freezing will
Page 142 and 143: accelerated frost damage or frost d
Page 144 and 145: A possible objection to the present
Page 146 and 147: [17] Dührkop H., Saretok V., Sneck
Page 149 and 150: Decay potential in wood structures
Page 151 and 152: Wood decaying fungi will only be ac
Page 153 and 154: to promote decay prevails. Two of t
Page 155: Acknowledgements This paper has bee
Page 158 and 159: (a driving rain gauge), however, is
Page 160 and 161: Fig. 1. Map of Norwayshowing the lo
Page 162 and 163: Frequency 25 20 15 10 5 0 highest p
Page 167 and 168: Effects of wind exposure on roof sn
Page 169 and 170: In ISO 4355 ”Bases for design of
Page 171 and 172: variety of roofs and wind exposures
Page 173 and 174: Li and Pomeroy [13] evaluated hourl
Page 175 and 176: Fig. 5. Exposure coefficients for 3
Page 177 and 178: meteorological stations are expecte
Page 179 and 180: Many of the meteorological stations
Page 181 and 182: the ground with return period of 30
Page 183: References [1] Standards Norway. De
show all

Lisø PhD Dissertation Manuscript - NTNU

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?