Developing a modelling factor index for transition spaces: a case study approach

Abstract

Transitional spaces (TS) are characterized by possession of high gradients of luminances between inside and out, which places a great demand on the users' visual system's function. A satisfactory descriptive indicator of this kind of situation could be a 'modelling factor' (MF), defined from cylindrical illuminance and horizontal illuminance measures. It would provide information on the depth and dimensionality of objects present in the scene, also taking into account a region's overabundance of daylight. A public building was selected as a case study, and solar light behaviour, including its interaction with the space, was monitored. Measurements were taken during an entire year at the start of each season (2008) under clear skies, at the beginning and at the end of each working day. Another measurement was taken in winter ( 2009) under overcast skies at 13:00, so as to obtain a comparative parameter. It was found that unfavourable conditions were produced in all seasons for about 2 hours, except at 09:15 in winter. All the data collected in the control situation were within the optimum modelling range, with values ranging between 0.3 and 0.4. The MF allows the integration of most relevant factors intervening in TS and emerges as a good descriptor for TS.

Transitional spaces from exterior to interior as functional vision barriers in ageing

“…It has semi-arid/dry weather with predominantly sunny skies, 2850 annual average sunlight hours. 23 This region is a typical case that presents very similar daylight conditions of the space previously studied by Lasagno et al 5 All measurements were performed under conditions of clear sky (sunny) at midday during Spring (from 11 am to 1:30 pm, November 26, 2010). The vertical illuminances measured on the eye of the observer were in the range 70,000 lux to 83,000 lux for the exterior, when the subject was standing at the starting point.…”

“…These are characterised by a predominant daytime use and a high availability of direct sunlight due to clear sunny skies. In a previous paper 5 we studied, from a photometric point of view, a similar typical transitional space measuring the differences between the exterior and the interior for the four seasons and at different times of the day. We found very large differences in horizontal illuminances between the outside and the inside in summer, from 130,000 lux to 59 lux, and also in winter, from 65,000 lux to 37 lux.…”

Daylight Management in Mediterranean Cities: When Shortage Is Not the Issue

“…The thermal requirements of users in this zone seem to be halfway between inside and outside and are more flexible than the requirements in static areas. In terms of visual comfort, the conception of it as a dynamic space determines the characteristics of the elements along the way [26] as well as other parameters related to daylight, such as the modelling factor [27].…”

Functional vision barriers: A new concept analyzed in terms of human visual performance.

“…Extensive studies investigated the relationship between lighting and functional vision from the perspectives of ergonomics and visual health (Regan & Neima, 1983;Charman, 1996;Owsley, Stalvey, Wells, Sioane, & McGwin, 2001;Brunnström, Sörensen, Alsterstad, & Sjöstrand, 2004) and performance of the lighting design (Irikura, Toyofuku, & Nygaard, 1999 Barraza, & Colombo, 2010;O'Donell, Colombo, & Boyce, 2011b), the presence of a glare source presented at the foveal and peripheral visual Aguirre, Colombo, & Barraza, 2008;Aguirre, Barraza, & Colombo, 2011), transitional spaces with high luminance variations (Lasagno, Pattini, Rodríguez, & Colombo, 2011), and illuminated spaces where luminous radiation Kirschbaum, 2011). Based on these published results, we present only three of these cited studies: (1) stimuli with low luminance contrast information in which the addition of chromatic contrast improves visual performance (O'Donell et al, 2010(O'Donell et al, , 2011b, (2) tasks foveally or peripherally presented in the presence of a glare source in al., 2008, 2011), and (3) instances in which the presence of a peripheral glare source reduces brightness perception consist of measures of visual performance determined by the reaction time (RT) paradigm, and the third example consists of another approximation based on the comparison of brightness perception.…”

“…Extensive studies investigated the relationship between lighting and functional vision from the perspectives of ergonomics and visual health (Regan & Neima, 1983; Charman, 1996; Owsley, Stalvey, Wells, Sioane, & McGwin, 2001; Brunnström, Sörensen, Alsterstad, & Sjöstrand, 2004) and performance of the lighting design (Irikura, Toyofuku, & Nygaard, 1999; Akashi & Rea, 2002; Lingard & Rea, 2002; Fotios & Boyce, 2005; Fotios & Cheal, 2007, 2011; Aparicio et al, 2010). Our previous works identified the following examples of functional vision barriers: stimuli with low luminance contrast (O’Donell, Barraza, & Colombo, 2010; O’Donell, Colombo, & Boyce, 2011b), the presence of a glare source presented at the foveal and peripheral visual fields under mesopic adaptation (Issolio & Colombo, 2006; Aguirre, Colombo, & Barraza, 2008; Aguirre, Barraza, & Colombo, 2011), transitional spaces with high luminance variations (Lasagno, Pattini, Rodríguez, & Colombo, 2011), and illuminated spaces where luminous radiation exhibits visible or non-visible flicker (Jaen, Colombo, & Kirschbaum, 2011). Based on these published results, we present only three of these cited studies: (1) stimuli with low luminance contrast information in which the addition of chromatic contrast improves visual performance (O’Donell et al, 2010, 2011b), (2) tasks foveally or peripherally presented in the presence of a glare source in the visual field that reduce visual performance (Aguirre et al, 2008, 2011), and (3) instances in which the presence of a peripheral glare source reduces brightness perception (Issolio & Colombo, 2006).…”