1、 Ayman Youssef is an Engineering Specialist at Saudi Aramco, Dhahran, Kingdom of Saudi Arabia. Climate Zone Map (CZM) Tool for Building Energy Code Compliance in Saudi Arabia Ayman Youssef, PE Member ASHRAE ABSTRACT Climate has a major impact on energy use in buildings, especially in Saudi Arabia. T
2、he Saudi Building Code, Energy Conservation Requirements (SBC-601), provides the minimum energy performance requirements for buildings and their systems. Since a critical factor in determining the overall energy consumption is the envelope dominated cooling load, numerous design tables are provided
3、in SBC-601 to help design offices that comply with the energy performance requirements for walls, roofs and windows for the various climatic conditions encountered in Saudi Arabia. So far, due to the complexities of SBC-601 and the lack of a simple building science-based climate zone map (CZM) for S
4、audi Arabia, neither builders nor designers have been able to demonstrate code compliance, and neither have the authorities having jurisdiction been able to mandate code enforcement properly. As a result, 70% of Saudi Arabian homes are today, for example, not insulated, which results in the consumpt
5、ion of nearly 52% of electrical power generated. This study explains the details of how the above-mentioned shortcomings can be addressed through development of a Kingdom-specific CZM online tool, which characterizes the SBC 601 minimum prescriptive energy efficiency performance requirements for res
6、idential and nonresidential building envelopes. The study also highlights the significant role this tool can play in facilitating code compliance and gives examples of the potential energy savings. INTRODUCTION The Kingdom of Saudi Arabia (KSA) has been subsidizing residential energy prices for deca
7、des, drawing on its vast hydrocarbon reserves. Meanwhile, energy consumption is growing faster than GDP, resulting in increasing energy intensities contrary to the general trend observed in most countries. This increasing trend is not only attributed to the energy-intensive industries and the energy
8、-intensive lifestyles in buildings and transport, but is also due to the adoption of low efficiency processes, which are encouraged by artificially low energy prices and a very hot climate, both of which encourage more energy consumption rather than less (Youssef and Hamid 2014). This has resulted i
9、n inefficient utilization of the countrys natural resources. In 2013, the residential, commercial and government building sectors consumed 126.4 TWh (Tera Watt hours), which represents around 75% of the total electrical energy consumed in the Kingdom (SEC 2013). Despite following international desig
10、n trends of modern architecture, as seen in many building typologies across the KSA, it is the use of energy efficiency design solutions that stops short in many cases. Since a critical factor for determining overall energy consumption is the envelope dominated cooling load, numerous climate-based e
11、nergy performance requirements exist for building envelope; these include, for example, maximum U values for walls, roofs and windows; maximum window-to-wall ratios; as well as maximum solar heat gain coefficients (SHGC) for windows. These requirements are included in the Saudi Building Code, Energy
12、 Conservation Requirements, SBC-601 (2003). So far, due to the complexities of SBC-601 and the lack of a simple building science-based CZM for Saudi Arabia, neither builders nor designers have been able to demonstrate code compliance, and neither have the authorities having jurisdiction been able to
13、 mandate code enforcement properly. As a result, it is estimated that 70% of Saudi Arabian homes are today, for example, not insulated (Youssef and Hamid 2014). This study explains the details of how the above-mentioned shortcomings can be addressed through development of a Kingdom-specific CZM to a
14、llow designers and builders to easily and quickly comply with the envelope energy efficiency requirements of the prescriptive compliance path of the building energy codes. This study also introduces this CZM as a Web-based interactive online tool and highlights the significant role it plays to facil
15、itate compliance with the prescriptive compliance path of building energy codes. Methods used to develop these CZMs are explained and compared with others in current use. Significant advantages of this new classification are highlighted, including the potential energy savings. PROPOSED SOLUTION Give
16、n the special national nature of the topic, it was necessary to review how building science-based CZMs were developed and applied in similar applications in different countries. The authors extensive literature reviews revealed that CZM development methodologies and application varies between countr
17、ies. For example, the Thailand CZM was developed based on a detailed statistical analysis of a large data set of air temperatures and relative humidity. The map was used to develop appropriate strategies for energy and building designs (Khedari, Sangprajak, and Hirunlabh 2002). The India CZM was dev
18、eloped based on analysis of the monthly climatic data for the air temperatures and relative humidity for 255 stations throughout the country. The map was used to meet basic design features in buildings, (e.g., set point temperatures and heat flow computations) (Sharafat, Sharma, and Maiteya 2011). T
19、he Turkey CZM was developed based on the annual driving rain index, which is computed from wind speeds and the heating degree days (HDD). The map was primarily used to mitigate the moisture degradation of building wall assemblies (Sahal 2006). In China, on the other hand, two approaches were present
20、ed. First, both a global solar radiation zone map and a thermal CZM were developed. The global solar radiation zone map was used in conjunction with the thermal CZM to assist building designers formulate their passive design strategies accordingly during the initial design phases of a building proje
21、ct. It also gave energy policy makers an idea on the potential solar energy conversions systems (Lau, Lam, and Yang 2007). The second approach introduced the bio climate zones in terms of long-term summer and winter discomforts of heat and cold stresses. Five bio climate zones have been identified w
22、hich were used to determine the extent of climate change on the cooling and heating requirements and hence the Chinese national energy policy (Wan, Li, Yang, and Lam 2010). The Australia CZM was developed using high quality spatial climatic data sets for in situ observations of rainfall, temperature
23、 and vapor pressure. The CZM was used to meet the energy efficiency provisions of the Australian building code in terms of reducing energy usage for cooling and heating services in warmer and colder climate zones respectively (Jones, Wang, and Fawcett 2009). The USA CZM, on the other hand, were deve
24、loped using the ASHRAE standard 90.1 and the International Energy Conservation Code (IECC) methodologies, which are based on temperature, precipitation, and heating and cooling degree days. The CZM was used to meet the buildings envelope energy efficiency requirements of the prescriptive compliance
25、path of the building energy codes and standards (ASHRAE 2010). Table 1 shows a condensed comparative summary of the various CZM development methodologies and their applications by country. From the above reviews in terms of development methodologies and applicability, the author determined that the
26、ASHRAE-based approach is most appropriate to develop the new CZM which characterizes the SBC-601 minimum prescriptive energy efficiency performance requirements for residential and nonresidential buildings envelopes. Table 1. CZM Development Methodology and Application by Country Country Development
27、 Methodology Application Thailand Detailed statistical analysis for large datasets for air temperatures and RH To develop appropriate strategies for energy and building designs India Analysis of the monthly climatic data for air temperatures and RH for 255 stations To meet basic design features in b
28、uilding and heat flow computations Turkey Annual driving rain index, computed from the wind speeds and HDD To mitigate moisture degradation of building wall assemblies Australia High quality spatial climatic data sets for in situ observations of rainfall, temperature and vapor pressure To meet the e
29、nergy efficiency provisions of the Australian building code China Global solar radiation zone map in conjunction with thermal CZM To assist building designers formulate passive design strategies during the initial design phase Heat and cold stress bio CZM To determine the extent of climate change on
30、 the Chinese national energy policy USA ASHRAE 90.1/IECC To meet the envelopes energy efficiency provisions of building codes and standards SAUDI ARABIA GEOPGRAPHY, TOPOGRAPHY AND CLIMATE Saudi Arabia is the largest Arab state in Western Asia by land area with approximately 830,000 sq. miles (2,150,
31、000 km2), constituting the bulk of the Arabian Peninsula. Located between latitudes 16 and 33 north and longitudes 34 and 56 east, it is bordered by Jordan and Iraq to the north; Kuwait to the northeast; Qatar, Bahrain and the United Arab Emirates to the east; Oman to the southeast; and Yemen in the
32、 south. It contains the worlds largest continuous sand desert (the Empty Quarter) with the southern regions elevated reaching up to 9,842 ft. (3,000 m) above sea level. Sandstorms driven by northwesterly winds persist for about three months each year, usually during the late spring and early summer,
33、 on the eastern coast (Wikipedia 2014). Saudi Arabias climate is generally hot and dry, with cool winter nights and high humidity along the coasts. The temperature during the summer reaches well over 113F (45C), with extreme winter temperatures well below 32F (0C). The daily maximum temperature is m
34、ild during the short spring and autumn seasons, averaging about 84.2F (29C) ( 2014). Rainfall is sparse and infrequent. The annual average precipitation ranges between 1 in (26 mm) and 13 in (330 mm) (Saudi Aramco 2014). The following sections describe the processes used to develop the CZM for Saudi
35、 Arabia and how it was published on the internet as an interactive tool intended for use by building designers and builders. STATIC CZM DEVELOPMENT A base map of Saudi Arabia was developed in AutoCAD Map using information derived from Google Map. Then, the locations of the meteorological stations in
36、 the KSA were entered into the base map along with topographic elevation contour lines, provinces and major cities. This AutoCAD map file served as the basis for analyzing the Saudi climate data and developing the climate classifications (ASHRAE Handbook 2009. The climate zones were developed using
37、ASHRAE 90.1 standard methodology, which divides the world climate into 8 climate zones, ranging from very hot (zone 1) to very cold (zone 8) and from dry (A) to moist (B) and marine (C) conditions. Each of these zones is defined by ranges of cooling degree days (CDD10), heating degree days (HDD18.3)
38、, annual average temperatures (T), and annual precipitation (P). The CZM for Saudi Arabia was developed by applying these thermal and climatic criteria to the climate data from 25 major cities across Saudi Arabia (14). The analysis revealed that Saudi Arabia has three climatic zones; namely, Very Ho
39、t (zone 1) and Dry (B), Hot (zone 2) and Dry (B) and Warm (zone 3) and Dry (B). The dry climate was deduced from the precipitation (P) and annual mean temperature (T) calculations as per the ASHRAE 90.1 methodology. None of the 25 cities were classified as being either moist (A) or marine (C). Table
40、 2. Analysis Results for the 25 Selected Cities ft m 1 8. 3C 65F 1 8. 3C 65F F C in mm in mmT u r a i f 2795 852 1262 2272 3443 6197 3 66 . 2 19 3. 27 83 20 . 55 522 BA r a r 1801 549 959 1726 4373 7871 2 71 . 6 22 2. 87 73 22 . 92 582 BG u r i a t 1654 504 1028 1850 3703 6665 2 68 . 0 20 1. 85 47 2
41、1 . 34 542 BA l - Q a i s u m a h 1175 358 553 995 5572 10030 1 77 . 0 25 4. 88 124 25 . 30 643 BT a b u k 2520 768 708 1274 4403 7925 2 71 . 6 22 1. 89 48 22 . 92 582 BA l - J o u f 2260 689 871 1568 4364 7855 2 71 . 6 22 2. 32 59 22 . 92 582 BR a f h a 1457 444 744 1339 4885 8793 2 73 . 4 23 3. 66
42、 93 23 . 72 602 BH a i l 3287 1002 758 1364 4431 7976 2 71 . 6 22 5. 12 130 22 . 92 582 BA l - W ej h 79 24 37 67 5412 9742 1 77 . 0 25 1. 02 26 25 . 30 643 BG a s s i m 2126 648 467 841 5402 9724 1 77 . 0 25 5. 98 152 25 . 30 643 BD h a h r a n 56 17 205 369 6121 11018 1 78 . 8 26 3. 27 83 26 . 09
43、663 BA l - A h s a 584 178 247 445 6261 11270 1 80 . 6 27 3. 62 92 26 . 88 683 BA l - M a d i n a h 2087 636 92 166 6612 11902 1 82 . 4 28 2. 56 65 27 . 68 703 BR i ya d h 2034 620 301 542 6009 10816 1 80 . 6 27 4. 57 116 26 . 88 683 BY a n b u 33 10 13 23 6523 11741 1 82 . 4 28 1. 42 36 27 . 68 703
44、 BJ i d d a h 56 17 1 2 6737 12127 1 82 . 4 28 2. 24 57 27 . 68 703 BM a kk a h 787 240 1 2 7742 13936 1 87 . 8 31 4. 33 110 30 . 05 763 BA l - T a i f 4767 1453 225 405 4748 8546 2 73 . 4 23 6. 89 175 23 . 72 602 BA l - B a h a 5420 1652 209 376 4638 8348 2 73 . 4 23 6. 06 154 23 . 72 602 BB i s h
45、a 3812 1162 121 218 5443 9797 1 77 . 0 25 3. 58 91 25 . 30 643 BA b h a 6867 2093 560 1008 3196 5753 3 66 . 2 19 12 . 99 330 20 . 55 522 BK h a m i s M u s h a i t 6745 2056 391 704 3587 6457 2 68 . 0 20 8. 66 220 21 . 34 542 BN a j r a n 3976 1212 136 245 5478 9860 1 78 . 8 26 2. 52 64 26 . 09 663
46、BS h a r o r a h 2379 725 63 113 6523 11741 1 82 . 4 28 2. 80 71 27 . 68 703 BG i za n 23 7 0 0 7409 13336 1 86 . 0 30 5. 28 134 29 . 26 743 BH D D C D DC i t yC l i m a t e Z o n eS a u d i A r a b i a C l i ma t i c D a t a S u mma r yS u b - r eg i o n (A , B , C )El ev a t i o nA n n u a l M ea
47、n T em er a t u r eA v er a g e A n n u a l p a r ci p i t a t i o n D r y T yp e C a l cu l a t i o n (a n n u a l p a r ci p i t a t i o n m u s t b e l es s t h a n t h i s v a l u e)Global parallel and meridian lines were used to demark the separation between climate zones 2 and 3 in the norther
48、n part of the Kingdom (Meridian 40 degrees east) and between zones 1 and 2 in the southwest of the Kingdom (Meridian 44 east). The separation between climate zones 1 and 2 along the Sarawat Mountains was set to correspond to the 4921 ft. (1500 meters) above sea level contour line. The final static m
49、ap was created, which includes province names, major cities, location of the Tropic of Cancer, the boundaries of the KSA with adjoining countries on the Arabian Peninsula and surrounding bodies of water. For ease of use, the three climate zones are color coded. Figure 1 shows the climatic classifications for Saudi Arabia as a result of this analysis. Figure 1 Climatic classifications map for Saudi Arabia (static). DYNAMIC CZM DEVELOPMENT The static CZM was converted into a dynamic, interactive website to allow design offices; building code offici
