Evaluation of Thermal Comfort Zone in Naturally Ventilated Offices in Bushehr

Providing thermal comfort is one of the most important goals in building design, which accounts for a large amount of energy consumption. In-office buildings, thermal comfort has a significant impact on indoor quality and staff productivity. In many countries, several methods and standards have been proposed to determine the thermal comfort zone for air conditioning and naturally ventilated buildings. In Iran, the lack of appropriate standards defining thermal comfort zones determines the necessity of research in this field. The present paper aims to determine the thermal comfort range in Bushehr office buildings with natural ventilation. Environmental indices (temperature, humidity, wind speed) were measured through field studies using data loggers in the three days from 19 to 21 March while 180 questionnaires were answered simultaneously by users. Based on the results, 81.1% of the subjects are comfortable with the overall thermal conditions. Using SPSS software, descriptive statistics analysis was performed between measured data and individual responses. During the research time in March, the average temperature is 19 ° C and the relative humidity is 65%. In this way, the comfort range is calculated based on two proposed equations for thermal comfort in different cities of Iran and compared with field measurements. According to the results of high temperature, the comfort zone in Bushehr office spaces is 28.6 degrees Celsius which is higher than the values from proposed equations for thermal comfort in Iran. There is a difference of 1.13 degrees between the neutral temperatures obtained by the two methods. More than 79% of the people are satisfied with the flow of air while 63% of the moisture content is satisfied. This shows the greater importance of the airflow in creating a feeling of comfort on the amount of moisture. In the case of thermal preference, 40% of people do not want a change in temperature, and 51.6% prefer small changes. In the case of humidity, 63.2% of the moisture conditions are satisfied and their 45% tendency to no change in moisture conditions. While 47.8% of people preferred modest changes in humidity (slightly damp or slightly moist), 32.4% prefer the environment without changing the airflow, and 52% prefer the air to more or more. Thus, despite the establishment of comfort conditions, the thermal preference for more than 36% of people is slightly lower and 17% less humidity and 52% more airflow. Regarding heat sensation and thermal preference, a suitable solution can be selected for flexible space design. The results of the questionnaires and the evaluation of behavioral parameters showed that the most important choice of the individuals to adapt to the thermal conditions is to stay in places with the possibility of wind flow. This issue shows the importance of the application of natural ventilation and its feasibility in space design. Therefore, to accurately determine the exact range of thermal comfort in Bushehr city, it is necessary to conduct extensive field study research in different seasons of the year in natural building ventilation buildings defining accurate thermal comfort zone.