## 3 Determination of Thermal Comfort  
The PMV/PPD model of [PERSON] [32] is an established model to predict thermal comfort under static conditions close to thermal neutrality and moderate indoor climates for a large group of people, where PMV represents the predicted thermal sensation and PPD the percentage of dissatisfied persons with the thermal environment [32]. In contrast, adaptive comfort models consider the human as an active part of the comfort assessment model. These adaptive models are more precise, especially inside naturally ventilated buildings with high adaptation possibilities of the occupants, because in this case, they represent the real environmental conditions more accurately than the PMV [39; 46; 47]. To consider this fact, [PERSON] and [PERSON] [48] transformed its PMV model into an adaptive PMVe model, using an expectancy factor, which reduces the calculated PMV in connection with the expectations of the occupants. Several adaptive models consider psychological, physiological and behavioral adaptation processes. For instance, the predictions of the adaptive models of [PERSON] et al. [49] and [PERSON] and [PERSON] [50] better present the real thermal sensation than predictions based on PMV [51]. The adaptive thermal heat balance model (ATHB) of [PERSON] and [PERSON] [52] combines the adaptive comfort approach of ASHRAE 55 [18], DIN EN 15251 [47] with [PERSON]'s PMV model. In this regard, the researchers developed equations that are used to dynamically modify the clothing insulation level and the metabolic heat production of the PMV model. Furthermore, the equations consider behavioral, physiological and psychological adaptation processes of individuals and were derived on the basis of ASHRAE RP884. The evaluation of the model was performed by the use of an independent dataset the researchers gained from experiments in their own test facility. The predicted results of the ATHB model show good agreement with experimental data and results produced by the PMV and ATC model. Finally, ATHB itself is assumed to be applicable to naturally ventilated and air-conditioned buildings. [PERSON] et al. [39] developed an adaptive model for the estimation of the optimal indoor air temperature that is linked to the outdoor air temperature. The determination of an equivalent temperature is a suitable approach for the thermal assessment of a heterogeneous indoor climate and facilitates the comparison between different thermal environments. Such a model is the \"Standard Effective Temperature\" (SET) [18; 53]. According to this model, the indoor air temperature of a fictive environment is calculated (50 % relative humidity, \(<\)0.1 m s\({}^{-1}\) air velocity, radiant temperature equals air temperature, 1 met, 0.6 clo) so that the thermal heat loss via the skin is equal in the fictive and real environment. DIN EN ISO 14505-2 [54], [PERSON] [55] describe the equivalent temperature model (Teq). This temperature corresponds to the calculated indoor air temperature of a fictive and thermally homogeneous room without air velocity so that the heat exchange via convection and radiation is equal between the fictive and real environment. International standards consider adaptive approaches for the assessment of naturally ventilated buildings [18; 47], but as [PERSON] et al. [51] have shown, adaptive models are also advantageous for the assessment of air-conditioned buildings. Thermal comfort can be determined through both, applying thermal comfort models and performing user surveys [56]. Since thermal sensation correlates with thermophysiological characteristics such as the body core temperature, skin temperature and sweating [57], the measurement of either the skin temperature or the body core temperature enables the determination of the contemporary thermal sensation [58; 59]. Skin temperature depends on clothing insulation and operative temperature [60] and can be measured at exposed locations using contactless infrared sensors.