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I have noticed that my lighting industry peers are increasingly focusing on carbon footprint cost and the sustainability of lighting systems.
Commendable use of their time as, from the U.S. Department of Energy to the New York Mayor's Office, the push is for 30 percent energy savings in buildings and the gradual cut of some 40 percent of total carbon emission.
So lighting efficiency is definitely on the radar screen, with lighting retrofits being channeled into compact fluorescent lamps and new lighting systems considering the use of expensive but efficient LED fixtures.
However, increasing imbalance is looming between our eagerness for energy efficiency and our nonchalance for inclusion of human factors and the impact that our energy efficiency measures will have on human health. And this is happening around the world.
A recent report released by the Department for Environment, Food and Rural Affairs in England provides lifecycle assessment of ultra-efficient lamps (pdf) by comparing several indicators such as air impact, water impact, soil impact, and resources impact, but there is no mention of direct human impact.
Similarly, guidelines for LEED certification and green buildings in United States, although well-intentioned, omit data on the impact that energy measures will have on human health. Never mind that scientists and clinicians working around the clock have compiled data on the direct connection between light and human health.
And while research continues, one finding is definitive -- that daylight represents a 100 percent healthy package for people, as it comes with views of nature and modulation of its parameters. We can describe daylight as a symphony of modulating spectrum, light intensities, and distributions with the passage of time. And while this modulation appears to be random, there is an underlying order of constancy in the liveliness and modulation of light.
The daylight cycling is reflected in the way human body functions, with peaks and valleys of hormonal production, with sleep and wake cycles, and with modulation of brain activity. We are basically synchronized with nature.
David Bohm, the quantum physicist, developed the concept of an enfolding and unfolding universe, where the whole is a craftsmanship of interconnected parts, and where the smallest part reflects the whole.
In a similar way the human body reflects the wholeness of nature. It is a simple inference that to emulate the daylight characteristics with electrical lighting systems will be healthy for people, while to use static lighting for people will be unhealthy.
Human Factors and the Built Environment
I applaud Ms. Simeonava's stance here relative to the importance of accounting for human factors in the design of our built environments. As an anthropologist and engineer working to make this more of a day-to-day reality, I am always heartened when I see this perspective from the design side.
Daylighting and exterior views are such a critical component of the human condition because of our species' deep history as hunter/gatherers. The physiological and psychological needs/constraints placed on our species are a result of evolving in an exterior environment as hunter/gatherers — a much different daily context than our current interior environments where we spend more than 90% of our time.
In addition, the social/cultural norms we learn as we grow up within a given intellectual tradition overlay these physiological and psychological factors, affecting how our brains are wired at an early age. They provide a lens through which we view and interpret the world around us, essentially generating our specific experience within any given situation or environment. As such, successful design and energy efficiency measures must take these varying physiological, psychological, and social/cultural factors/needs into account.
Thermal comfort provides an additional example beyond lighting. Thermal comfort is the state of mind resulting from our ability to maintain thermal equilibrium with the surrounding environment. It is dependent primarily on the following six factors: air temperature, mean radiant temperature, air movement/velocity, relative humidity, activity levels, and the insulative properties of clothing - the last of these is highly dependent on social/cultural norms. The socially/culturally acceptable clothing styles that we grow up with, which are part of the norms we learn from our family, peers, schooling, company policies, and the mass media, and which vary by activity/task/job description, gender, age, class, and culture, are part of what generate the experience of being thermally comfortable in a given situation. The perception of thermal comfort is therefore tied not only to our physiological and psychological reactions to the above six factors, but also to our ideas of “social comfort” related to conforming to one's social/cultural clothing norms. This creates many potential settings for thermal comfort conflicts among different demographic groups possessing different clothing norms (and therefore different insulative values of dress) — including the classic modern conflict between male and female office workers.
Marcel Harmon
Natural Lighting
I enjoyed reading this article. While I have heard and read about some of these factors before, this took a deeper, though still brief, look at them. I recently noticed a difference in my energy level when I moved to a new apartment with less natural light. It is very noticable when buildings take advantage of not just natural light, but adjustable lighting systems.
Energy Efficiency and Human Factors
This is a well thought out, well written article. Ms. Simeonova "sheds light on" the research aspects of lighting as well as the day to day effects in people's lives. My partner and I have chosen both cool and warm "happy lights" because they each affect our moods differently. Lighting combinations (some cooler, some warmer, some balanced) seem to make the "full spectrum" lights actually feel fuller.
This article has piqued my curiosity and I plan to read more. Bravo!