Circadian rhythms - Revision history

Editor at 11:48, 6 January 2023

2023-01-06T11:48:28Z

← Older revision		Revision as of 11:48, 6 January 2023
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	--[[User:CIAT\|CIAT]]		--[[User:CIAT\|CIAT]]

−	= Related articles on Designing Buildings ~~Wiki~~ =	+	= Related articles on Designing Buildings =

	* 7 ways better lighting can improve your health.		* 7 ways better lighting can improve your health.

Designing Buildings at 07:47, 5 February 2021

2021-02-05T07:47:58Z

← Older revision		Revision as of 07:47, 5 February 2021
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	* Use of lighting to improve health and wellbeing.		* Use of lighting to improve health and wellbeing.

−	[[Category:~~Research_/_Innovation~~]] [[Category:DCN_Research,_Development_and_Innovation]]	+	[[Category:DCN_Commentary]] [[Category:DCN_Guidance]] [[Category:DCN_Research,_Development_and_Innovation]] [[Category:Research_/_Innovation]]

Designing Buildings at 09:20, 5 March 2020

2020-03-05T09:20:07Z

← Older revision		Revision as of 09:20, 5 March 2020
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	The project findings are described in detail in various outputs, including the following publications:		The project findings are described in detail in various outputs, including the following publications:

−	# BRE Trust report summarising this project, which is available at: ~~http~~:www.bretrust.org.uk/knowledgehub/~~healthwellbeing~~-~~safety~~/circadian-rhythms/	+	# BRE Trust report summarising this project, which is available at: [https://www.bretrust.org.uk/knowledgehub/wellbeing/circadian-rhythms/ https://www.bretrust.org.uk/knowledgehub/wellbeing/circadian-rhythms/]
	# Design manual for solar shading (BRE Trust Report) and two BRE information papers on retrofitting solar shading and control of solar shading – [http://www.brebookshop.com http://www.brebookshop.com]		# Design manual for solar shading (BRE Trust Report) and two BRE information papers on retrofitting solar shading and control of solar shading – [http://www.brebookshop.com http://www.brebookshop.com]
	# CIBSE Journal article [http://www.cibsejournal.com/technical/ http://www.cibsejournal.com/technical/] evaluating-dynamic-lighting		# CIBSE Journal article [http://www.cibsejournal.com/technical/ http://www.cibsejournal.com/technical/] evaluating-dynamic-lighting
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	* Use of lighting to improve health and wellbeing.		* Use of lighting to improve health and wellbeing.

−	[[Category:Research_/_Innovation]]	+	[[Category:Research_/_Innovation]] [[Category:DCN_Research,_Development_and_Innovation]]

Designing Buildings at 09:18, 5 March 2020

2020-03-05T09:18:30Z

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	Circadian rhythms are physical, mental and behavioural changes that follow a daily cycle. Found in most living things, they respond primarily to light and darkness in an organism’s environment. Sleeping at night and being awake during the day is an example of a light-related circadian rhythm.		Circadian rhythms are physical, mental and behavioural changes that follow a daily cycle. Found in most living things, they respond primarily to light and darkness in an organism’s environment. Sleeping at night and being awake during the day is an example of a light-related circadian rhythm.
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Designing Buildings at 09:17, 5 March 2020

2020-03-05T09:17:33Z

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	Circadian rhythms are physical, mental and behavioural changes that follow a daily cycle. Found in most living things, they respond primarily to light and darkness in an organism’s environment. Sleeping at night and being awake during the day is an example of a light-related circadian rhythm.		Circadian rhythms are physical, mental and behavioural changes that follow a daily cycle. Found in most living things, they respond primarily to light and darkness in an organism’s environment. Sleeping at night and being awake during the day is an example of a light-related circadian rhythm.
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Designing Buildings at 09:13, 5 March 2020

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← Older revision		Revision as of 09:13, 5 March 2020
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−	A study of 23 people working in an open-plan office ~~has been~~ carried out by research scientists at BRE, with BRE Trust and CIBSE funding, to translate experimental knowledge about the effects of lighting in the workplace into real-world good practice. A BRE Trust report summarising this project and providing advice on circadian lighting is available.	+	A study of 23 people working in an open-plan office was carried out by research scientists at BRE in 2018, with BRE Trust and CIBSE funding, to translate experimental knowledge about the effects of lighting in the workplace into real-world good practice. A BRE Trust report summarising this project and providing advice on circadian lighting is available.

	= Introduction =		= Introduction =
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	# BRE Trust report summarising this project, which is available at: http:www.bretrust.org.uk/knowledgehub/healthwellbeing-safety/circadian-rhythms/		# BRE Trust report summarising this project, which is available at: http:www.bretrust.org.uk/knowledgehub/healthwellbeing-safety/circadian-rhythms/
−	# Design manual for solar shading (BRE Trust Report) and two BRE information papers on retrofitting solar shading and control of solar shading – http://www.brebookshop.com	+	# Design manual for solar shading (BRE Trust Report) and two BRE information papers on retrofitting solar shading and control of solar shading – [http://www.brebookshop.com http://www.brebookshop.com]
−	# CIBSE Journal article http://www.cibsejournal.com/technical/ evaluating-dynamic-lighting	+	# CIBSE Journal article [http://www.cibsejournal.com/technical/ http://www.cibsejournal.com/technical/] evaluating-dynamic-lighting
	# Draft papers on findings of the field study for publication in Lighting Research and Technology scientific journal.		# Draft papers on findings of the field study for publication in Lighting Research and Technology scientific journal.

	-----		-----
−	This article originally appeared in Architectural Technology Journal (at) issue 132 published by CIAT in winter 2019. It was written by the Building Research Establishment (BRE).	+	This article originally appeared in [http://library.myebook.com/CIAT/at-journal-132-winter-2019/2190/ Architectural Technology Journal] (at) issue 132 published by CIAT in winter 2019. It was written by the Building Research Establishment (BRE).

	--[[User:CIAT\|CIAT]]		--[[User:CIAT\|CIAT]]

Designing Buildings at 09:12, 5 March 2020

2020-03-05T09:12:08Z

Show changes

Designing Buildings at 09:01, 5 March 2020

2020-03-05T09:01:33Z

← Older revision		Revision as of 09:01, 5 March 2020
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−	#~~redirect~~:[~~[Lighting_for_circadian_rhythms\|~~Lighting for circadian rhythms]]	+	A study of 23 people working in an open-plan office has been carried out by research scientists at BRE, with BRE Trust and CIBSE funding, to translate experimental knowledge about the effects of lighting in the workplace into real-world good practice. A BRE Trust report summarising this project and providing advice on circadian lighting is now available.
		+
		+	Circadian rhythms control human alertness, sleep and the release of hormones. Daytime exposure to light, especially blue light, helps synchronise the circadian clock, enabling us to feel alert during the day and sleepy at night. Many people work in poorly daylit spaces with relatively low levels of electric light, where it may be hard for their bodies to maintain their circadian rhythms.
		+
		+	Dynamic ‘circadian’ lighting is being marketed using dimmable, colour-tuning LEDs to give brighter, bluer light in the middle of the day, and dimmer light – with less blue – later in the day when it is time to relax. However, little or no research has been done on the best way to control this tuneable lighting under real-world conditions. Research was needed to help translate experimental knowledge into practice and investigate the effects of dynamic lighting and its timing on how people feel (i.e. their subjective assessments), and their activities and reported sleep.
		+
		+	Lighting conditions investigated
		+
		+	This research took the form of a BRE field study, with 23 participants working in an open-plan office at the University of East Anglia. Four conditions were administered over several weeks during winter months:
		+
		+	Condition 1
		+
		+	Old constant fluorescent lighting – i.e. the office’s existing lighting, from 19 February to 2 March 2018.
		+
		+	Condition 2
		+
		+	New dynamic LED system – with variable LED lighting at a lower level, from 12-23 March 2018.
		+
		+	Condition 3
		+
		+	New dynamic LED system – with variable LED lighting at a higher level, from 12-23 November 2018.
		+
		+	Condition 4
		+
		+	New dynamic LED system – set up to provide constant lighting, from 3-14 December 2018.
		+
		+	Factors that were measured
		+
		+	Site measurements, lighting monitoring and computer modelling were combined with subjective and objective measures of performance, including questionnaires, regular pop-up questions and computer-based performance tests, along with the monitoring of light exposure and level of activity of participants using activity tracking watches.
		+
		+	The responses of the participants to questions and computer-based tests were assessed to identify links between key participant performance indicators – subjective alertness, reaction time and concentration – and the measurement and calculation results of circadian light metrics for each of the four lighting conditions.
		+
		+	Participant answers to general questionnaires following each lighting condition were also analysed and compared to assess the potential impacts of variable lighting. In addition, these results were correlated with the activity level data and the measurements of the site’s environmental conditions – temperature and relative humidity.
		+
		+	Research findings
		+
		+	Greater alertness
		+
		+	The average scores for subjective alertness were significantly better with the new dynamic LED system (Condition 2), than with the old constant fluorescent lighting (Condition 1). Comparisons of average subjective alertness scores with the LED systems set up to provide variable lighting (Condition 3), and constant lighting (Condition 4), revealed no statistically significant differences.
		+
		+	Extra light not a factor
		+
		+	Most participants felt more alert under the dynamic LED lighting in Condition 2 compared to the constant fluorescent lighting in Condition 1, but this also happened for the small number of people who received less light in Condition 2. The increase in alertness did not depend significantly on how much extra light people had with the LEDs. All participants received more light in Condition 3, compared to Condition 4, and the increase in light level was much more uniform across participants compared to the first conditions. However, the higher light levels in Condition 3 did not lead to higher scores, on average, for subjective alertness – only half of the participants felt more alert under the dynamic LED lighting (Condition 3).
		+
		+	Other factors not affected
		+
		+	There were no statistically significant differences in test scores for reaction time and concentration and in sleep metrics between the two conditions tested in each phase of the project.
		+
		+	Preference for dynamic lighting
		+
		+	In each phase, participants were asked whether they would prefer dynamic or constant lighting. On average, just over half of them preferred dynamic lighting for their office, typically brighter in the morning and following the variation of natural light outdoors throughout the day. Just under one third preferred the constant lighting.
		+
		+	More questions to answer
		+
		+	Overall, there is still considerable uncertainty about how much light is required for circadian entrainment – i.e. for a person’s circadian rhythm to align with the rhythms of light. People vary in their normal daily routines and in how much daylight they are exposed to. In addition, even in a space with ‘uniform’ electric lighting some people may receive significantly more light into their eyes than others, depending on which way they face.
		+
		+	More research is therefore still needed to understand better the potential impacts of lighting on circadian entrainment and wellbeing in real-life situations, and how to best quantify these in order to produce clear recommendations and guidelines for lighting than can support healthy circadian rhythms and wellbeing.
		+
		+	Outputs
		+
		+	The project findings are described in detail in various outputs, including the following publications:
		+
		+	# BRE Trust report summarising this project, which is available at: bretrust.org.uk/knowledgehub/healthwellbeing- safety/circadian-rhythms/
		+	# 2. Design manual for solar shading (BRE Trust Report) and two BRE information papers on retrofitting solar shading and control of solar shading – brebookshop.com
		+	# 3. CIBSE Journal article (cibsejournal.com/technical/ evaluating-dynamic-lighting),
		+	# 4. Draft papers on findings of the field study for publication in Lighting Research and Technology scientific journal.
		+
		+	What are circadian rhythms?
		+
		+	Circadian rhythms are physical, mental and behavioural changes that follow a daily cycle. Found in most living things, they respond primarily to light and darkness in an organism’s environment. Sleeping at night and being awake during the day is an example of a light-related circadian rhythm.
		+
		+	Daylight and solar shading guidance
		+
		+	One way of providing circadian lighting is the abundant provision of daylight in buildings. This can also lead to issues of unwanted solar heat gain and glare unless carefully designed solar shading is provided. An additional objective of this project, therefore, was to complete production of BRE guidance documents on solar shading. These were a Design manual for solar shading and two BRE information papers on retrofitting solar shading and control of solar shading – available from [http://www.brebookshop.com http://www.brebookshop.com]
		+
		+	This article originally appeared in Architectural Technology Journal (at) issue 132 published by CIAT in winter 2019. It was written by the Building Research Establishment (BRE).
		+
		+	Related articles on Designing Buildings Wiki
		+
		+	* 7 ways better lighting can improve your health.
		+	* BREEAM Reduction of night time light pollution.
		+	* BREEAM Visual comfort Daylighting.
		+	* Building Research Establishment.
		+	* CIAT articles.
		+	* CIAT.
		+	* Daylight benefits in healthcare buildings.
		+	* Health and wellbeing impacts of natural and artificial lighting.
		+	* Human-centric lighting.
		+	* Lighting and health FB 74.
		+	* Lighting for circadian rhythms.
		+	* Lighting.
		+	* Use of lighting to improve health and wellbeing.

Designing Buildings: Redirected page to Lighting for circadian rhythms

2019-11-03T07:44:47Z

Redirected page to Lighting for circadian rhythms

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#redirect:[[Lighting_for_circadian_rhythms|Lighting for circadian rhythms]]