Radiant air-conditioning systems and floor-supply displacement heating, ventilation, and air conditioning (HVAC) systems have recently attracted considerable attention. However, such systems have not yet seen widespread use because the degree to which they increase thermal comfort is not clear. In this study, the authors measured the planar thermal deviation during summer in four offices: two offices employed a radiant air-conditioning system and a floor-supply displacement HVAC system, and the other two offices employed convective air-conditioning systems.<br> No noticeable difference is observed in the average air speed among the offices. However, for the convective air-conditioning system in offices, the air speed had a wide distribution. In contrast, for the floor-supply displacement HVAC system and the radiant air-conditioning system, the air speed was highly consistent with minimal variation (<0.1 m/s). This minimal variation in the air speed was therefore perceived as being calm compared to the air speed variation for the convective air-conditioning system. Moreover, for the convective air-conditioning system, the local air turbulence tended to be higher than that for the radiant air-conditioning system and the floor-supply displacement HVAC system.<br> For the convective air-conditioning system (multi air-conditioning system), the equivalent temperature repeatedly rose and fell during operational hours. On the other hand, for the floor-supply displacement HVAC system and the radiant air-conditioning system, the air temperature was very stable during operational hours.<br> The authors characterized both the temporal and spatial thermal environmental variations for various air-conditioning systems. In all the cases, the planar standard deviation was concentrated at low values during air-conditioning operation downtimes such as midnight and early morning. In convective air-conditioning system (multi air-conditioning system) and floor-supply displacement HVAC system, the equivalent temperature tended to be high during air-conditioning operation downtimes, especially early morning. During operational hours, according to the characteristics of the convective air-conditioning system (multi air-conditioning system), the equivalent temperature tended to fluctuate wildly and attain high planar standard deviations. On the other hand, in TABS, the equivalent temperature was concentrated at low values during air-conditioning operation downtimes such as midnight and early morning. In addition, the equivalent temperature did not fluctuate because the temperature in TABS is considered to be a typical example of a TABS that uses the thermal capacity of slabs to provide a stable thermal environment.