H.B.Gunay et aL Building and Ervironment 70 (2013)31-47 Behavior Windows Blinds Lights {2838-471 3 49,52,611 29,32,48.50.51.52 169-721 69-724 .581 Wind/ View Visibility of Thermal Acoustic Rain IAQ Visual Privacy Health Energy-Use 2334.42,48.49 128,38-471 2334.47 58.60.611 32.48.52,6166 164,67,68 681 169-721 69-724 Reversal Windows Blinds Lights Fig.3.Behavior to adaptive system and reversal of adaptive system. 2.1.10.Predictability of the occupants:active and passive ASHRAE Standard 55-2010 [14]recommends to use clothing levels The adaptive occupant behavior has been deemed as individual of 0.5 clo and 1.0 clo,in summer and winter,respectively.Most but not arbitrary [57.suggesting that individual occupants,despite recently.Schiavon and Lee [107]reported that median clothing the fact that their accumulated response is stochastic,undertake insulation for summer as 0.59 clo and for winter as 0.69 clo, control actions consciously and consistently [51-54,80-82,97-991 respectively.This suggested that seasonal clothing level variations For example,Lindsay et al.52]reported that the frequency of are significantly smaller than it is assumed by ASHRAE [141.Haldi manual blind adjustments varies from never to daily even in the and Robinson[108]reported that seasonal clothing level variations same facade,however,adjustments remain predictable for the in- have an amplitude notably larger than those observed within a day. dividual office level.Therefore,it was suggested that there are as shown in Fig.5.They also studied the behavioral adaptation by "passive"and "active"occupants according to their interaction with drinking hot or cold beverages and by changing the activity level. the windows [10,31,78,86].lights and blinds [51-54,80-82,98,99]. From their results it can be inferred that occupants consume more Boyce [82]reported that manual light control in shared offices are hot drinks during the heating season and more cold drinks during consistently performed by the same group of people.Passive oc- the cooling season.No seasonal dependence was reported in the cupants were observed to be consistently less reactive to thermal reviewed literature about the adjustment of the activity level. variations,while active occupants undertook control actions more frequently.Rijal et al.[10]asked subjects how frequently they 2.2.2.Observation techniques,time and state discretization adjust their windows.Fig.4a shows that subjects who responded as Studying personal adaptive behaviors,unlike the environmental "never"have a distinct way of interacting with their windows adaptive behaviors is challenging due to its invasive nature[1091.It compared to those who responded as "sometimes/seldom"and is challenging to place sensors or to carry out a time-lapse "often".In line with these findings,Reinhart and Voss [57]reported photography survey in order to study personal adaptive behav- models for manual lighting use for single or doubled occupied of- iors.Two techniques were observed in the reviewed literature:(1) fice spaces (see Fig.4b)and Haldi and Robinson [65]reported observational field surveys [100,102.110]and (2)self-reported models for manual blinds use for single or double occupied office questionnaire surveys [39,108,111.112].In the observational field spaces(see Fig.4c).These models indicate that occupants under- surveys,the researchers simply observe a group of subjects and take adaptive behaviors at wildly different indoor conditions.This their personal adaptive behaviors in their daily routines for a suggests that some occupants prefer darker indoor environments, certain period of time.In the self-reported questionnaire surveys, while some prefer brighter indoor environments.Some had more subjects are recruited participants such that they are aware of the consistent light level preferences,while some had less predictable scope of research and are being observed.The observational studies preferences. give the opportunity to monitor the state in a very small scale.For example,Wyon and Holmberg [110]carried out an observational 2.2.Behaviors that adapt the personal characteristics survey on primary school students and revealed small scale diurnal clothing adjustments such as an opening collars or rolling up Based on a summary of 30 field studies,Humphreys [100]in sleeves.In a self-reported survey,the questionnaire size and fre- 1975 observed a relatively small variation in the reported thermal quency should be kept short for practical reasons.For example, sensation over a range of indoor temperatures from 17 to 30C.This Haldi and Robinson [108]discretized the clothing level in the observation,despite not being completely applicable in today's questionnaire response in eight different clothing assemblies(e.g. fully-conditioned office buildings,is a clear indication of occupants' shirt with short sleeves,sandals,and shorts)that would result in adaptation of their personal characteristics to accommodate to between 0.3 and 0.95 clo.It was also acknowledged that this dis- their environment.This is typically achieved by adjusting their cretization was a deliberate compromise and this might have also clothing and activity levels(e.g.siestas)and by drinking colder/ caused a loss of information about the small scale diurnal clothing hotter beverages. level changes.For example a small,yet significant variation of the clothing level of the order of 0.1 clo might have occurred more 2.2.1.Seasonal effects frequently than relatively large level variations.A similar approach Most of the early research efforts [101-106]have shown that was also used in discretization of the activity level with six possi- clothing level of the occupants vary notably from season to season bilities such as seated relaxed or sedentary activity.Drinks were by observing the same group of subjects.In line with these studies, discretized as a binary state,which was a reasonable assumption2.1.10. Predictability of the occupants: active and passive The adaptive occupant behavior has been deemed as individual but not arbitrary [57], suggesting that individual occupants, despite the fact that their accumulated response is stochastic, undertake control actions consciously and consistently [51e54,80e82,97e99]. For example, Lindsay et al. [52] reported that the frequency of manual blind adjustments varies from never to daily even in the same facade, however, adjustments remain predictable for the in￾dividual office level. Therefore, it was suggested that there are “passive” and “active” occupants according to their interaction with the windows [10,31,78,86], lights and blinds [51e54,80e82,98,99]. Boyce [82] reported that manual light control in shared offices are consistently performed by the same group of people. Passive oc￾cupants were observed to be consistently less reactive to thermal variations, while active occupants undertook control actions more frequently. Rijal et al. [10] asked subjects how frequently they adjust their windows. Fig. 4a shows that subjects who responded as “never” have a distinct way of interacting with their windows compared to those who responded as “sometimes/seldom” and “often”. In line with these findings, Reinhart and Voss [57] reported models for manual lighting use for single or doubled occupied of- fice spaces (see Fig. 4b) and Haldi and Robinson [65] reported models for manual blinds use for single or double occupied office spaces (see Fig. 4c). These models indicate that occupants under￾take adaptive behaviors at wildly different indoor conditions. This suggests that some occupants prefer darker indoor environments, while some prefer brighter indoor environments. Some had more consistent light level preferences, while some had less predictable preferences. 2.2. Behaviors that adapt the personal characteristics Based on a summary of 30 field studies, Humphreys [100] in 1975 observed a relatively small variation in the reported thermal sensation over a range of indoor temperatures from 17 to 30 C. This observation, despite not being completely applicable in today’s fully-conditioned office buildings, is a clear indication of occupants’ adaptation of their personal characteristics to accommodate to their environment. This is typically achieved by adjusting their clothing and activity levels (e.g. siestas) and by drinking colder/ hotter beverages. 2.2.1. Seasonal effects Most of the early research efforts [101e106] have shown that clothing level of the occupants vary notably from season to season by observing the same group of subjects. In line with these studies, ASHRAE Standard 55-2010 [14] recommends to use clothing levels of 0.5 clo and 1.0 clo, in summer and winter, respectively. Most recently, Schiavon and Lee [107] reported that median clothing insulation for summer as 0.59 clo and for winter as 0.69 clo, respectively. This suggested that seasonal clothing level variations are significantly smaller than it is assumed by ASHRAE [14]. Haldi and Robinson [108] reported that seasonal clothing level variations have an amplitude notably larger than those observed within a day, as shown in Fig. 5. They also studied the behavioral adaptation by drinking hot or cold beverages and by changing the activity level. From their results it can be inferred that occupants consume more hot drinks during the heating season and more cold drinks during the cooling season. No seasonal dependence was reported in the reviewed literature about the adjustment of the activity level. 2.2.2. Observation techniques, time and state discretization Studying personal adaptive behaviors, unlike the environmental adaptive behaviors is challenging due to its invasive nature [109]. It is challenging to place sensors or to carry out a time-lapse photography survey in order to study personal adaptive behav￾iors. Two techniques were observed in the reviewed literature: (1) observational field surveys [100,102,110] and (2) self-reported questionnaire surveys [39,108,111,112]. In the observational field surveys, the researchers simply observe a group of subjects and their personal adaptive behaviors in their daily routines for a certain period of time. In the self-reported questionnaire surveys, subjects are recruited participants such that they are aware of the scope of research and are being observed. The observational studies give the opportunity to monitor the state in a very small scale. For example, Wyon and Holmberg [110] carried out an observational survey on primary school students and revealed small scale diurnal clothing adjustments such as an opening collars or rolling up sleeves. In a self-reported survey, the questionnaire size and fre￾quency should be kept short for practical reasons. For example, Haldi and Robinson [108] discretized the clothing level in the questionnaire response in eight different clothing assemblies (e.g. shirt with short sleeves, sandals, and shorts) that would result in between 0.3 and 0.95 clo. It was also acknowledged that this dis￾cretization was a deliberate compromise and this might have also caused a loss of information about the small scale diurnal clothing level changes. For example a small, yet significant variation of the clothing level of the order of 0.1 clo might have occurred more frequently than relatively large level variations. A similar approach was also used in discretization of the activity level with six possi￾bilities such as seated relaxed or sedentary activity. Drinks were discretized as a binary state, which was a reasonable assumption Fig. 3. Behavior to adaptive system and reversal of adaptive system. 38 H.B. Gunay et al. / Building and Environment 70 (2013) 31e47