**1. Introduction**

Natural ventilation has great potential for cooling buildings with a passive strategy because it improves user comfort and indoor air quality, while simultaneously reducing electricity usage demand [1–5]. Thermal comfort has a great impact on the well-being and performance of users, as well as the energy requirements of buildings [6]. Moreover, in developed countries, people spend 90% of their time indoors, which requires securing their well-being and a healthy environment [7].

Reducing active cooling requires passive solutions; therefore, utilizing glass on external walls has a great impact on thermal situations through its influence on energy demand for the cooling and heating of buildings [8].

An adaptive approach to thermal comfort relies on outdoor air temperature and the individuals' thermal environment [9]. Adaptive comfort limits are similar for hothumid and hot-dry climates with a 0.6 coefficient value. Additionally, air movement

is important for a hot-humid climate, while indoor relative humidity (RH) is important for a hot-dry climate [10]. In hot-humid climate environments, relative humidity is not significant when it is below 70%, but is really significant when higher than 70% with increasing air temperature [11].

Sustainable approaches for energy efficient buildings are very important to architects and engineers for the provision of comfortable and health-conscious buildings [12]. In addition to these, adaptive thermal comfort can be used to design energy efficient (low-energy) naturally ventilated buildings around the world [13].

The aim of this study was to determine the minimum, maximum, and yearly averages of naturally ventilated office performance, as well as the impact of the wall-towindow ratio on thermal comfort due to solar gain, heat loss, resultant temperature, relative humidity, and external air temperature. Moreover, the analysis focuses on the office's performance in relation to the winter and summer season (based on each month), heat transfer (conduction), and energy transfer (convection) for opaque and glass walls (internally and externally). In identifying the naturally ventilated office performance (minimum, maximum, and yearly) and the seasonal performance of the office (based on conduction-convection), this article hopes to fill in existing gaps in the literature for hot-humid climatic conditions.

## **2. Literature review**

Heat transfer through the opaque walls of buildings is important for energy saving and thermal comfort issues. Cities in Turkey such as Ankara, Erzurum, Istanbul, and Izmir with different climates were analyzed using the TS825 standard (Turkish standard on thermal insulation requirements for buildings) [14]. It was found that 15-cm- and 25-cm-thick sandwich panels created a decrease of 65% and 80% heat loss and gain respectively during the worst winter and summer conditions. The optimal heat loss and gain ratios under different climatic conditions were determined using sandwich wall insulation. Heat transfer for different building orientations was found to be longer in the summer period due to solar radiation [15]. Radiative heat transfer was higher during daytime than the evening in summer, with no significant changes during the spring, autumn, and winter periods [16].

In the subtropical climate of China, out of eight free-running dormitories, 1829 returned questionnaires with subjective scales indicated that 15.9–28.2°C were acceptable temperatures, where 23.2°C was the preferred temperature and 22.1°C was the neutral temperature based on students' thermal perception and preferences. Moreover, the students' air movement sensation was 53% satisfied with the indoor air humidity when thermal sensation was neutral [17]. In Tuxtla Gutiérrez-México, 496 data points were collected from 27 educational buildings in the warm season. In air-conditioned mode, 48.1% of users felt comfortable, 44% felt cold, and 7.9% felt warmth. However, in naturally ventilated mode, 59.7% felt comfortable, 11% felt cold, and 29.3% felt warmth. Most of those who felt cold can have their thermal satisfaction improved by adapting rooms to slightly higher temperatures [18]. In the hot-humid part of China, naturally ventilated buildings have a thermal neutrality of 25.4°C, 23.5°C for 90% acceptability, and 27.4°C for the 80% acceptability range. In naturally ventilated buildings in China with a hot-humid climate, the Predicted Mean Vote (PMV) model can be used with a 0.822 expectancy factor [19].

In two Indian cities, Chennai with a humid climate and Hyderabad with a composite climate, the mean room temperature was 28.8°C for naturally ventilated mode *Adaptive Thermal Comfort of an Office for Energy Consumption-Famagusta Case DOI: http://dx.doi.org/10.5772/intechopen.101077*

but 26.2°C for air-conditioned mode with 45% and 48% relative humidity ratios, respectively [20].

Naturally ventilated buildings in hot-humid climate conditions should have a minimum of 0.65 m/s indoor air speed for thermal comfort [10]. In north-east Brazil, 90% acceptability of thermal comfort for a naturally ventilated building needs from 24 to 27°C room temperature with 0.4 m/s air movement, while from 27 to 29°C needs a minimum of 0.41–0.81 m/s air velocity, and a room temperature from 29 to 31°C needs a minimum of >0.81 m/s air velocity [21].

Tianjin is a city in China where 80% adaptive comfort acceptability ranges between room temperatures of 21°C and 27.3°C [22].

The national code for India has a narrow thermal comfort range that is between 21 and 26°C for all naturally ventilated building types and seasons. A questionnaire with 2610 responses found that the comfort ranges were 30.6°C with 0.30 clo dress and 0.62 m/s preferred air velocity for the summer season, and 25.2°C with 0.80 clo dress and 0.27 m/s preferred air velocity for the winter season [23].

A survey conducted in Spain found that 23.6°C is the observable average operative temperature in (free-running and air-conditioned) buildings. Moreover, it is very clear that an adaptive comfort model is suitable for hybrid buildings [24]. In India, the ideal comfort temperature was determined to be 27.3°C, while the actual preferred temperature is 24.5°C. Half of all the fans in offices start working after 31°C, with no fan needed up to 22.5°C [25].
