Sıcak iklim bölgeleri için enerji etkin kabuk elemanı dizaynında kullanılabilecek bir yaklaşım

Abstract

Bu çalışmada sıcak iklim bölgelerinde enerji etkin kabuk ele manı dizaynında uygulanabilecek bir yaklaşım tanıtılmaktadır. Yapılan çalışmada amaç, binalarda kullanılan yapma ısıtma ve iki imlendirme sistemlerinin beraberinde getirdiği enerji harcamala rını minimuma indirebilmek için kabuk elemanlarının pasif sistem öğe leri olarak optimal performansa sahip olmalarının sağlanmasıdır. Bu nedenle enerji etkin kabuk elemanı dizaynında kullanılan yapma çevre ye ilişkin dizayn değişkenlerinden kabuk elemanının yönlendiril iş du rumu ve optik ve termofiziksel özellikleri bu amaç doğrultusunda in celenerek uygun "Değerler Kombinezonları" belirlenmektedir. Bu yak laşım altı ana bölümden oluşmaktadır. Bölüm Vde, yapılan çalışmayla ilgili kısa bilgi verilerek, enerji etkin kabuk elemanı dizaynında etkili olan dizayn değişkenle rine ait ele alınan hedefler belirtilmektedir. Bölüm 2'de, ısıtma ve iklimlendirme enerjisi kullanımını zo runlu kılan faktörlerden başlıcası olan iklimsel konfor gereksinmesi incelenmektedir. Bölüm 3'de, ısıtma ve iklimlendirme enerjisi korunumunu zorun lu kılan faktörler kısaca açıklanmaktadır. Bölüm 4'de, ısıtma ve iklimlendirme enerjisi korunumunda etki li olan fiziksel çevresel etkenler ve yapma çevreye ilişkin dizayn değişkenlerinden kabuk elemanının yönlendiril iş durumu ve optik ve termofiziksel özellikleri tanıtılmaktadır. Bölüm 5'de, sıcak iklim bölgelerinde ısıtma ve iklimlendirme enerjisi korunumu açısından bina kabuğu termofiziksel özelliklerine ilişkin uygun değerlerin belirlenmesinde kullanılabilecek yöntem açıklanmaktadır. Bölüm 6'da ise 5. bölümde açıklanan yöntem Kuzey Kıbrıs Türk Cumhuriyeti (K.K.T.C.) için enerji etkin bina kabuğu dizaynında kul lanılabilecek değerlerin belirlenmesi amacıyla uygulanmıştır. Yöntemin uygulanması sonucunda hazırlanan grafik sistemler ve tablolar yardımıyla yapma çevreye ilişkin dizayn değişkenlerinden ka buk elemanının yönlendiriliş durumu ve optik ve termofiziksel özel liklerine ait uygun değerler kombinezonları belirlenmiştir.

In this study an approach which can be used in energy effi cient building envelope design for hot regions is introduced. Building envelopes should be designed as optimum passive system ele ments which consume supplementary mechanical heating and climatisa- tion energy at the minimum level. This study comprises six main chapters. In chapter 1, a brief explanation related to energy efficient building envelope design is given. In chapter 2, the main factors which make heating and climat- isation energy utilization compulsary (climatic comfort requirements) are examined. In chapter 3, the factors which make energy conservation com pulsory are shortly described. In chapter 4, climatic factors effective on the determination of appropriate values of design parameters which are used in the definition of the building envelope as passive heating and climatisa- tion system element are classified. The main climatic factors are;. solar radiation,. external air temperature,. relative humidity and. air velocity. A group of primary design parameters which are related to building envelope and affective on energy conservation are as fol lows.. orientation of building envelope,. thermophysical and solar radiation (optical) properties of the building envelope. Orientation of building envelope is one of the most important factor affecting indoor climate as the solar radiation intensity on - vii - to select the appropriate values for thermophysical properties of building envelope. These values define building envelope which performs at the optimum level from the energy economy standpoint. The main criterion, which is used in selecting the appropriate values for each combination of window type, opaque component absorp tivity and orientation, is given below; "The building envelope that provides minimum heating and climatisation energy expenditure and minimum energy cost through a year, is qualified as the most appropriate one." The sub-criteria used in selecting the optimum values are as follows:. Same opaque component detail should be applied to all the facades of the building because of the application simplicity.. Different opaque component details can be applied to each facade of the building.. Transparency ratio should be equal to 20% or greater than 20% in order to satisfy human needs for visual communication with the outside world. 4- Opaque component alternatives are developed by basing on the chosen k0 and transparency ratio. 5- For all of the opaque component alternatives which have been developed, the condensation risk must be examined. As the result of these calculations and evaluations, combina tions of appropriate values for the thermophysical properties that define building envelope which performs at the optimum level in achieving climatic comfort, energy economy and elimination of the condensation risk, can be determined. In chapter 6, the method, described in previous chapter is applied for Turkish Republic of Northern Cyprus (a hot-humid region), in order to determine the optimum values for thermophysical proper ties of the building envelope. Finally, as the results of this thesis study, some graphic systems and tables are prepared. These graphic systems and tables include the combinations of appropriate values for thermophysical properties and opaque component details and provide architects great simplicity in the selection of appropriate building envelope. representative design day for each of the periods. 21st of January and 21st of July are respectively the design days of underheated and overheated periods. - Gathering Meteorological Data for the Design Days. In order to predict the thermal behaviour of the building en velope, climatic variables, such as solar radiation data and varia tion of outdoor dry bulb temperature, should be taken into considera tion under the "real sky" conditions. - Selection of the Indoor Design Conditions. It is known that inner surface temperature of a building en velope significantly affects the thermal comfort of occupants in a room. The permissible limit value of inner surface temperature of a building envelope for each of the chosen design days can be estimated by using the following formulas: t.-yok = t.j - e (for underheated period) tiyoy = t^ + e (for overheated period) where e : permissible limit value for the difference between inner surface temperature and indoor air temperature, °C. - Selection of Variation Range and Intervals of the Design Parameters Affecting Indoor Climate In order to determine the appropriate overall heat transfer coefficient value, it is necessary to choose the values of other de sign parameters, such as orientations, thermophysi cal properties of the transparent components in reference to window type, transparency ratios and the solar radiation properties of the opaque components. - Calculation of Sol-Air Temperatures Instead of analysing the effects of the solar radiation and the outdoor air temperature on the building envelope seperately, it is recommended to use a fictious temperature, called sol-air tempera ture, derived from the outdoor air temperature and the solar radia tion. Sol-air temperatures for opaque and transparent components are calculated seperately, because the solar radiation properties of opaque materials are different from those of transparent materials. Hourly values of sol -air temperatures influencing the opaque and transparent components are calculated in accordance with their solar radiation properties and orientations. Daily average values of sol- air temperatures for opaque and transparent components (teog and tecg, respectively) are the arithmetic mean of hourly values. - IX representative design day for each of the periods. 21st of January and 21st of July are respectively the design days of underheated and overheated periods. - Gathering Meteorological Data for the Design Days. In order to predict the thermal behaviour of the building en velope, climatic variables, such as solar radiation data and varia tion of outdoor dry bulb temperature, should be taken into considera tion under the "real sky" conditions. - Selection of the Indoor Design Conditions. It is known that inner surface temperature of a building en velope significantly affects the thermal comfort of occupants in a room. The permissible limit value of inner surface temperature of a building envelope for each of the chosen design days can be estimated by using the following formulas: t.-yok = t.j - e (for underheated period) tiyoy = t^ + e (for overheated period) where e : permissible limit value for the difference between inner surface temperature and indoor air temperature, °C. - Selection of Variation Range and Intervals of the Design Parameters Affecting Indoor Climate In order to determine the appropriate overall heat transfer coefficient value, it is necessary to choose the values of other de sign parameters, such as orientations, thermophysi cal properties of the transparent components in reference to window type, transparency ratios and the solar radiation properties of the opaque components. - Calculation of Sol-Air Temperatures Instead of analysing the effects of the solar radiation and the outdoor air temperature on the building envelope seperately, it is recommended to use a fictious temperature, called sol-air tempera ture, derived from the outdoor air temperature and the solar radia tion. Sol-air temperatures for opaque and transparent components are calculated seperately, because the solar radiation properties of opaque materials are different from those of transparent materials. Hourly values of sol -air temperatures influencing the opaque and transparent components are calculated in accordance with their solar radiation properties and orientations. Daily average values of sol- air temperatures for opaque and transparent components (teog and tecg, respectively) are the arithmetic mean of hourly values. - IX to select the appropriate values for thermophysical properties of building envelope. These values define building envelope which performs at the optimum level from the energy economy standpoint. The main criterion, which is used in selecting the appropriate values for each combination of window type, opaque component absorp tivity and orientation, is given below; "The building envelope that provides minimum heating and climatisation energy expenditure and minimum energy cost through a year, is qualified as the most appropriate one." The sub-criteria used in selecting the optimum values are as follows:. Same opaque component detail should be applied to all the facades of the building because of the application simplicity.. Different opaque component details can be applied to each facade of the building.. Transparency ratio should be equal to 20% or greater than 20% in order to satisfy human needs for visual communication with the outside world. 4- Opaque component alternatives are developed by basing on the chosen k0 and transparency ratio. 5- For all of the opaque component alternatives which have been developed, the condensation risk must be examined. As the result of these calculations and evaluations, combina tions of appropriate values for the thermophysical properties that define building envelope which performs at the optimum level in achieving climatic comfort, energy economy and elimination of the condensation risk, can be determined. In chapter 6, the method, described in previous chapter is applied for Turkish Republic of Northern Cyprus (a hot-humid region), in order to determine the optimum values for thermophysical proper ties of the building envelope. Finally, as the results of this thesis study, some graphic systems and tables are prepared. These graphic systems and tables include the combinations of appropriate values for thermophysical properties and opaque component details and provide architects great simplicity in the selection of appropriate building envelope.vı representative design day for each of the periods. 21st of January and 21st of July are respectively the design days of underheated and overheated periods. - Gathering Meteorological Data for the Design Days. In order to predict the thermal behaviour of the building en velope, climatic variables, such as solar radiation data and varia tion of outdoor dry bulb temperature, should be taken into considera tion under the "real sky" conditions. - Selection of the Indoor Design Conditions. It is known that inner surface temperature of a building en velope significantly affects the thermal comfort of occupants in a room. The permissible limit value of inner surface temperature of a building envelope for each of the chosen design days can be estimated by using the following formulas: t.-yok = t.j - e (for underheated period) tiyoy = t^ + e (for overheated period) where e : permissible limit value for the difference between inner surface temperature and indoor air temperature, °C. - Selection of Variation Range and Intervals of the Design Parameters Affecting Indoor Climate In order to determine the appropriate overall heat transfer coefficient value, it is necessary to choose the values of other de sign parameters, such as orientations, thermophysi cal properties of the transparent components in reference to window type, transparency ratios and the solar radiation properties of the opaque components. - Calculation of Sol-Air Temperatures Instead of analysing the effects of the solar radiation and the outdoor air temperature on the building envelope seperately, it is recommended to use a fictious temperature, called sol-air tempera ture, derived from the outdoor air temperature and the solar radia tion. Sol-air temperatures for opaque and transparent components are calculated seperately, because the solar radiation properties of opaque materials are different from those of transparent materials. Hourly values of sol -air temperatures influencing the opaque and transparent components are calculated in accordance with their solar radiation properties and orientations. Daily average values of sol- air temperatures for opaque and transparent components (teog and tecg, respectively) are the arithmetic mean of hourly values.