Investigating the behaviour of ASHRAE, Bedford, and Nicol thermal scales when translated into the Arabic language

With the global spread of thermal comfort studies, thermal scales are translated into different languages to adapt local context in which the studies are applied. However, translating thermal comfort studies does not maintain the scales' behaviour associated with the original English versions. Behaviour differences include irregular categories' width, asymmetry, and deviation of the middle category centre from the centre of the thermal continuum. These differences have a negative influence on the results of thermal comfort studies and their accuracy. Applying the successive categories method, this paper explores the change in ASHRAE, Bedford, and Nicol scales' behaviour when translated into the Arabic language. The translated scales were integrated into questionnaires distributed among female high school students in Muscat, the capital city of Oman, as part of a larger survey that lasted for a whole year. The findings revealed the deviation of the translated scales from the original assumptions of the English versions. This included categories' irregular widths and asymmetry in addition to the deviation of the centre of the middle categories from the centre of the thermal continuum. Besides, it was found that both ASHRAE and Bedford scales covered different ranges on the thermal continuum, which questions their assumed equivalence. Based on these findings, the accuracy of the thermal comfort analysis is negatively affected. Considering the sensitivity of scales' behaviour to the used phrases, further explorations implementing the terms examined in this study are recommended. Abstract With the global spread of thermal comfort studies, thermal scales are translated into different languages to adapt local context in which the studies are applied. However, translating thermal comfort studies does not maintain the scales' behaviour associated with the original English versions. Behaviour differences include irregular categories' width, asymmetry, and deviation of the middle category centre from the centre of the thermal continuum. These differences have a negative influence on the results of thermal comfort studies and their accuracy. Applying the successive categories method, this paper explores the change in ASHRAE, Bedford, and Nicol scales' behaviour when translated into the Arabic language. The translated scales were integrated into questionnaires distributed among female high school students in Muscat, the capital city of Oman, as part of a larger survey that lasted for a whole year. The findings revealed the deviation of the translated scales from the original assumptions of the English versions. This included categories' irregular widths and asymmetry in addition to the deviation of the centre of the middle categories from the centre of the thermal continuum. Besides, it was found that both ASHRAE and Bedford scales covered different ranges on the thermal continuum, which questions their assumed equivalence. Based on these findings, the accuracy of the thermal comfort analysis is negatively affected. Considering the sensitivity of scales' behaviour to the used phrases, further explorations implementing the terms examined in this study are recommended

Using a New Programme to Predict Thermal Comfort as a Base to Design Energy Efficient Buildings

A strong relationship relates the thermal comfort and the consumption of energy, especially in the hot arid climate where the installation of HVAC systems is unavoidable. In fact, it has been reported that the HVAC systems are responsible for consuming huge amounts of the total energy used by the buildings that can globally reach up to 40% of the total primary energy requirement. The future estimations indicate that the energy consumption is likely to continue growing in the developed economies to exceed that of the developed countries in 2020. Under these situations, it seems that the shift towards more energy efficient buildings is not an option. Because part of any successful environmental design is to understand the potentials of the site, the proposed programme (THERCOM) assists in weighing the indoor and outdoor thermal comfort in different climates in order to provide better understanding of the site environment as well as testing the thermal comfort chances of the initial concepts

Design and simulation of a new energy conscious system, (ventilation and thermal performance simulation)

This paper presents the results of simulating the ventilation and thermal performance of a new passive cooling and heating system. The new system was integrated into the roof of a typical contemporary North African house, which was modelled and mounted inside a wind tunnel, for natural ventilation simulation. Thermal performance of the new system was simulated using a new computer programme (BTS), developed by the author. Results are presented in terms of indoor temperature and CATD and HATD, which are newly introduced concepts in defining the building cooling and heating loads.BTS CATD Cooling Heating HATD ventilation Wind tunnel

A new computer program for the prediction and analysis of human thermal comfort

This paper describes a new computer program, which was written for the prediction and analysis of human thermal comfort. The program incorporates six thermal comfort indices; three original and three modified versions of the original. The original indices are; Fanger's Comfort Equation, Sharma's Tropical Summer Index and Madsen's Equivalent temperature. Results produced by the program are presented in terms of the same PMV scale (Predicted Mean Vote). The six indices are, however, classified as three for summer and three for winter.Comfort equation Equivalent temperature PMV Thermal comfort TSI

Impact of Received Solar Radiation on Energy Potential of Ground Integrated Buildings on Slope Terrain

Depending on its local characteristic and other factors as climate conditions and soil thermal properties, the ground may absorb a large part of the solar radiation received by the earth’s surface. To a certain depth, the ground can act as an indirect heat energy source since it is able to collect, store and transmit energy. Buildings’ thermal performance can benefit from using this indirect solar energy through earth-coupling strategies. EnergyPlus’ Basement Auxiliary program is a useful tool for thermal simulation of buildings with direct ground contact. However, input data such as terrain tilt or orientation is not available in this software. This limitation means that the ground heat transfer calculations offered by this program always assume that ground-integrated buildings are placed on horizontal terrains. Through the use of a mathematical model, the authors explained how undisturbed ground temperatures under a flat terrain are different from those under slope terrain. Consequently, the authors argued that terrain inclination and orientation should be included as parameters for simulations of the ground heat transfer of buildings. Two elements that Labs’ equation uses to calculate ground temperature are solar radiation aspects as the mean annual temperature of the surface of the soil (Tm) and the annual range of the temperature wave at the soil’s surface (As). In this paper, the authors analysed the impact of using the appropriate solar radiation values for calculating ground thermal potential of slopes, which was done by using the corresponding solar radiation data for Lisbon surface tilts from 0° to 60°, with 5° intervals and with zero Azimuth. The resulting analysis showed that, as consequence, Tm and As values are affected, proving that ground temperatures below slopes are different from those registered under flat terrains. The authors demonstrated that all terrain inclinations provide higher annual ground thermal potential than equivalent flat terrain, and that between flat and sloped terrain an intermediate ground temperature zone is produced. The authors therefore concluded that for this location, 30° to 40° slopes are the best terrain inclination to achieve maximum ground thermal potential

Design and simulation of a new energy-conscious system (CFD and solar simulation)

This paper presents the use of a validated CFD programme (FLUENT) and a solar simulator, for designing a solar water-heater. The water-heater is part of a new passive cooling and heating system introduced for buildings in North Africa. CFD transient simulations were carried out using a small time-step of 10 s and a set of fine body-fitted computational grids (1770-4740 nodes). FLUENT results were then verified against indoor testing employing a solar simulator. Good agreement was achieved.CFD Fluent Solar simulator Water-heater

Design and simulation of a new energy conscious system, (basic concept)

A new passive cooling and heating system is introduced in this paper. The system was designed to be adaptively, integrated into the fabric and layout of buildings in North Africa. After discussion of the passive thermal design principles, a number of traditional and modern passive cooling and heating strategies are reviewed and analysed. Lessons learned from these examples have greatly helped design the new system. Development of the new system was based on both architectural design and principles of building engineering.Energy conscious North Africa Passive cooling Passive heating Traditional

Mathematical model for calculating the shaded and sunlit areas in a circular courtyard geometry

This paper presents a mathematical model that was developed specifically to calculate the produced shaded and sunlit areas in a circular courtyard geometry. It examines the interaction taking place between the sun at any time throughout the year and a circular courtyard form with any dimensions and proportions in any place on the earth. This model was included in a new computer program, which allowed detailed investigation to be undertaken into the effect of circular courtyard proportions on the generated wall and floor exposed and shaded areas. The results showed that changing the form's proportions significantly influences the shading or exposure potential of the internal courtyard envelope

Effect of courtyard proportions on solar heat gain and energy requirement in the temperate climate of Rome

The present study focuses mainly on the effect of solar heat gain on the energy demand of courtyard building form with different proportions. Several methods can be employed to improve the building's utilization of solar heat gain. This includes using light colours for the external surfaces to reduce the solar radiation absorption in summer, using shading devices and improving the thermal properties of the external walls and roof. However, it is of great importance before using any of these methods to have the courtyard building's architectural design adapted to have full advantage of the available solar heat gain. Therefore, the main objective of the present examination was to find out to what extent the building's solar heat gain and consequently the energy requirements are influenced by the building's configurations. A computer Tool (IES) was used to carry out the investigation taking Rome as an empirical