## 4 Personal Climatization Systems
### Desk-Mounted Personal Actuators  
Personal climatization systems at workplaces that consist of desk-mounted climate actuators improve thermal comfort and perceived air quality. Most of the related studies address cooling via ventilation using fans that are mounted above or below the desk. Some of them use radiation or conduction to improve thermal sensation and comfort. An overview of the corresponding literature and their results is given in Table A1. The thermal performance of immobile climate actuators is sensible to the location and posture of the related person. If a person leaves the climatization area, the thermal impact of manually operated desk-mounted ventilation system drops [86; 87]. In contrast, horizontal movement of the occupant does not significantly influence the thermal performance of a ventilator. Using air movement can provide thermal comfort up to an ambient temperature of 28 \({}^{\circ}\)C and a relative humidity of 80%. According to [PERSON] and [PERSON] [88], [PERSON] et al. [89] this is feasible by using a table fan (maximum energy consumption of 3 W) with a supply air velocity of 1.5 m s\({}^{-1}\) (Table A1-1, A1-12). Supplying air at a velocity of 2.3 m s\({}^{-1}\) at ambient temperatures of up to 30 \({}^{\circ}\)C is comfortable and leads to a thermal acceptance higher than 80 % [89]. A fan (average air velocity 0.8 m s\({}^{-1}\)) with air velocity profiles that are comparable to natural wind has a higher cooling effect than constant airflow of the same average air velocity [76; 84] (Table A1-8, A1-9, A1-10). According to [PERSON] et al. [84], a variable airflow provides higher thermal comfort than a constant airflow at an ambient temperature of at least 30 \({}^{\circ}\)C. Since horizontal and varying air speeds that are directed towards the face have a high ventilation efficiency, it can save up to 21.34% of cooling energy, when compared to a constant personal air flow [90].  
[PERSON] et al. [91] used thermal manikins for investigations of the cooling power related to different air speeds produced through an under-desk-mounted ventilation device (maximum volumetric air flow 70 L s\({}^{-1}\)). Therefore, the cooling power temperature equivalent that is necessary for the climatization of an entire person equals 4 K at 28 \({}^{\circ}\)C and 3 K at 26 \({}^{\circ}\)C. According to [PERSON] et al. [92] the local temperature effect that can be produced by an under-desk-mountedheating panel at an ambient temperature of 20 \({}^{\circ}\)C equals a 2.8 K increase in overall room temperature, using mixing ventilation. [PERSON] et al. [93] (Table A1-5) showed that a personal HVAC system with automated control can provide the same thermal comfort as a user-controlled system, if the ventilation load profiles are equal. However, occupants prefer scenarios with user-controlled ambient conditions. According to [PERSON] et al. [94], a water cooled table surface (cooling power 130.7 W) that cools the upper body region, ensures global thermal comfort at ambient temperatures between 28 \({}^{\circ}\)C to 32 \({}^{\circ}\)C (Table A1-3). In such scenarios, however, occupants are expecting increased air movement. The investigated table surface temperature used in their study was set between 22.8 \({}^{\circ}\)C and 25.5 \({}^{\circ}\)C, respectively. [PERSON] et al. [95] showed that a heated desk pad improves thermal comfort of occupants at an ambient temperature of 18 \({}^{\circ}\)C (Table A1-2).