## 4 Personal Climatization Systems
By using PEC both, thermal air quality and perceived air quality, are consequently superior to lighting quality, furnishing, conception of space and room acoustics [29], which is contrary to existing evaluations of these factors in conventionally conditioned buildings [17, 29]. Several local actuators for personal climatization systems are used in the automotive sector. Most widely used are seat heating/cooling, heated steering wheels and heated side panels. According to [PERSON] et al. [12], seat heating alone is not able to provide thermal comfort at 17.4 \({}^{\circ}\)C (dissatisfaction partly \(>\)40%). In contrast, a combined personal heating system, consisting of seat heating, heated steering wheel, heated side panels and heated panels in close distance to the feet ensures thermal comfort down to an ambient temperature of 16 \({}^{\circ}\)C [13]. A detailed overview of the currently available, personal climatization systems is summarized in Tables 1-6. In general, personal climate actuators can be classified into three groups:  
* local personal ventilation
* local radiant panels
* combined local thermal actuators (radiation, convection)All three groups are further divisible into the following categories, in close correlation to their individual thermal effect:  
* large area air-conditioning of multiple body parts (Tables A2-A5)
* local air-conditioning of single body parts (Tables A1, A4 and A6)  
Most of the listed studies were performed under controlled ambient conditions within laboratory studies and need further validation in the field. Current field studies [29; 76; 77; 78; 79] confirm the potential of personal HVAC systems in terms of thermal comfort. Fundamentally for the investigation of personal HVAC systems are studies assessing the correlation between whole-body and local thermal sensation. Most of the personal cooling systems are based on the local enhancement of air velocity for the improvement of the thermal comfort. Increasing air velocity improves both, thermal comfort and perceived air quality [80]. Commercially available fans used for the generation of air movement do not contain any definition of the cooling power. The calculation of the thermal compensation related to the energy consumption of ventilation systems leads to a benchmark (CFE) of the cooling power of several applied ventilation systems [81]. Similar to this, [PERSON] et al. [28] developed a general benchmark (CP) for local thermal actuators, which act close to the human body. It requires a standardized experimental setup for the comparison of the air-conditioning performance between different thermal actuators such as different fans. This is important for the transferability of these results to arbitrary environments. [PERSON] et al. [82] investigated various experimental setups and their impact on the performance estimation of ceiling fans. Without a known comparable cooling/heating power, the obtained results of their studies are only comparable with respect to the used thermal actuators. Varying air velocity that is similar to natural wind decreases thermal sensation more considerably than a constant air velocity [76; 83; 84]. According to [PERSON] and [PERSON] [85], the ventilation of the head, hands and feet is more effective than the ventilation of the head only (Table A1-6).