Long-term patterns of use of occupant controlled office lighting

Abstract

This paper reports daily and seasonal patterns of lighting use in offices where occupants were able to vary the level of illuminance falling on their working areas. The results show that occupants set a wide range of illuminances, many of which are significantly below CIBSE Code recommendations leading to significant energy savings throughout the year. Although users report use of controls for a variety of reasons, the results of the long-term monitoring of switching behaviour reveals that very few in fact use them for anything other than to switch on upon arrival at work, with further use of systems during the day being rare. Evidence suggests that the way in which systems are configured exerts influence over the level of electric light occupants work under. There is some evidence of an effect of daylight availability on levels set but little evidence to suggest pervasive and consistent user preferences for levels of electric light.

A critical review on questionnaire surveys in the field of energy-related occupant behaviour

“…When the cross-sectional questionnaire survey data could be complemented with additional datasets, such as environmental measurements, more sophisticated statistical methods could be used to find a connection between variables. This connection was described through correlation in many studies (Brundrett 1977) (Iwashita and Akasaka 1997) (Moore et al 2003) (Lutzenhiser 1992) (Price and Sherman 2006) (Guerra-Santin and Itard 2010) (Becker and Paciuk 2009) (Hua et al 2011). Others also managed to build a regression model to describe the nature of the connection (Frontczak et al 2012) (Humphreys 2005) (Raja et al 2001) (Meier and Rehdanz 2010) (Sardianou 2008) (Rijal 2008) (Bekö et al 2011) (Brager et al 2004) (Warren and Parkins 1984) (Rijal et al 2007).…”

“…These issues include: (1) participants knowingly or unknowingly misrepresenting their behaviour (also in Moore, et al (Moore et al 2003), Lutzenhiser (Lutzenhiser 1992) (Lutzenhiser 1993)), (2) participants may not recall their behaviour or their severity of discomfort (Burak Gunay et al 2014), and (3) participants may respond the way they think they are expected . These error types are categorized as measurement errors by Lohr (Leeuw et al 2008).…”

“…The study showed that the energy-saving potential of occupancy sensors should be revised, taking into account this change in occupant behaviour. Daily and seasonal patterns of artificial light use were studied (Moore et al 2003). Survey results showed a variety of reasons why occupants switched on lights, but primarily when they arrived in the office.…”

Lighting Design in Europe: Aligning the Demands for Lower Energy Usage with Better Quality

“…Additionally, improvements in mood, lighting satisfaction, and discomfort achieved by giving people individual control of their lighting are proportional to the difference between the fixed illuminance and the preferred illuminance [37]. An extensive field study [38,39] has also shown that direct/indirect lighting suspended over each workstation and providing individual control is considered better than uniform lighting with simple switching, and it saves energy.…”

“…Different people prefer varying illuminances for the same task. It has also been established that those buildings with most overrides are also the most energy efficient [34][35][36][37][38][39].…”