"In order to control the
sun's radiation the control over it's heat and warmth is essential;
because daylight is not used simply to illuminate an interior spaces,
the issue is not whether or not to use a window, but whether one can
capitalize on it to increase occupant comfort, satisfaction, and perhaps
productivity.
Tips for Daylighting, LBNL-39945,
Ernest Orlando Lawrence Berkeley National Laboratory. Pp2-1).
The importance of daylight in working environment is beyond any doubt.
In order to illustrate the benifits of suncontrol of using sunlight,
our attention will be focussed on three mayor fields.
First of al shall be dealt with the relation between illumination
and it's influence on the occupant's metabolism, more specifically
on comfort and health.
Secondly shall we handle the economical aspect of daylight usage.
We will illustrate the bearing of suncontrol on productivity.
Finally we shall briefly focus our attention on the enironment friendly
aspect of solar energy.
Comfort and health.
Spaces with ample daylight increase the occupants comfort and health.
Although difficult to quantify, daylight does increase occupant satisfaction.
Consciderable research on this subject has been conducted by TERNOEY,
PLANTS, TERMAN & QUITKIN, and extensive work conducted by Hopkinson
on the influence of buildings on the psycho-physiological state of
occupants. The general findings sustain the theory that buildings
with good levels of natural light do increase the satisfaction of
owners and occupants.
This research has shown the positive influence of the visual perception
of the exterior. Not only find occupants it pleasant to have a visual
relationship with the outdoors, but the perception of sunlight also
gives rhythm to our lives. This rhythm results from the variation
along the day and night as well as along the seasons. This is of help
in the adjustment of essential systems such as body temperature. A
lack of daylight contributes to insomnia, fatigue, headaches, sickness,
faintness and Seasonal Affective Disorder (SAD).
"Daylight
varies constantly and our eye adapts very easily to it as opposed
to artificial light wich is percieved as tiring and dull."
Light Therapy for Seasonal Affective
Disorder: a review of efficacy, M. Terman, J.S. Terman, F.M. Quitkin,
1987.
Strong illumination enhances details, texture shape and colour
Although daylight is essential for our well-being, there can be too
much of it. By controlling the sunlight which enters a building, one
contributes to the health of the occupants and avoids discomfort.
Because psychological discomfort physiological dizziness can occur
under disadvantageous lumination.
In case of unbalanced contrast levels or glare, the occupant cannot
distinguish objects and depth. Proper shading devices can help. Another
result of using good shading devices is to cut down the negative consequences
of HVAC usage. Less air conditioning means less negative ions in the
air, which results in a vitalizing influence on the occupant. Working
conditions improve and the sick-building-syndrome decreases.
Productivity and cost-effective design approach.
In order to design an effective daylighting system it within the workframe
of 'a global integrated approach'.
Because a balance of several components must be achieved: type of
activity inside the building, artificial lighting, solar heat gain,
the reduction of light through glazing and the internal heat gains.
In order to design a comfortable energy-efficient building the additional
cost for controlling the building' s climate must offset the costs
of buying, installing, use and maintenance of the heating and light
control system.
Because of the fact that daylight produces less heat than many artificial
lights and that cooling easily takes 30 to 40 % of the total energy
consumption of commercial buildings, an intelligent sunlight control
can drastically cut back expenses. Even so daylight penetration produces
suplementary building heat, which induces higher coolingloads. Controlling
the penetration of daylight plays an essential role in energy efficiency.
Heat control represents seven percent of building's costs over its
entire life cyclus, but the total energy expense can be seriously
cut down.
A good shading system reduces the amount of solar radiation which
penetrates a space hence heat, and diminishes the cooling loads. Suncontrol
increases the occupants productivity It can reduce the absenteeism
of occupants. Wages and saleries represent more then nine tenths of
all costs of a typic office building.
"Well controlled
daylight can account for a reduction in sickness and absenteeism which
can rapidly account for the initial morecost"
Daylight
Design and Analysis, Claude Robbins, Van Nostrand Reinhold Company,
New York,1986.
"The NMB Bank headquarters in
the Netherlands was designed in order for the daylight to enter deep
in the building (architect Ton Alberts). The desks are no further
than 6 m from a window opening and baffles are used to help it penetrate
deeper in the building. The bank has remarked a significant drop in
employee abstenteeism."
NMB Bank Headquarters, William Browning, Urban Land, 1992.
"After having add skylights to the Wal-mart in Lawrence, KS,
the company's vice-president claimed a 'significantly higher' sales
in the new lit portion of the store."
Letting
the Sun Shine is Good for Business, The Wall Street Journal, Monday,
Nov. 20, 1995, pg. B1. taken from Daylight: Healthy, Wealthy &
Wise by Barbara Erwine and Lisa Heschong.
Sick
building syndrom.
Next to the reduction in cost of HVAC installation and the increase
in occupants productivity, an intelligent sun control preserves the
value of the built and tend to have lower tenants-exchange.
Decreases the impact on the environment.
By reducing the energy needed to bring a space at a certain comfort
level less energy is spilled, thus reducing the impact on the environment.
Conscidering the fact that our fosil fuels are limited an intelligent
sun control alternative energy is bound to gain importance. References.
REFERENCES
E. NOELL, Daylighting Design, Energy Environment & Architecture,
American Institute of Architects, Washington, DC, 1992.
US ARMY CORPS OF ENGINEERS, Energy Conscious Design, Norfolk.
VA AMERICAN INSTITUTE OF ARCHITECTS, Building Connections, Energy
and Resource Efficiencies, Washington, DC, 1993 AIA, V. Loftness,
Defining "Fresh Air" Architecture, Proceeding fron mhe 18th
national Passive Solar Conference, American Solar Energy Society,
Boulder CO, 1993 S.
TERNOEY, The design of Energy-responsive Commercial Buildings, John
Wiley, New York,1985.
C.G.H. PLANTS, The light of day, Light and Lighting,1970.
W. BROWNING, NMB Bank Headquarters, Urban Land, 1992.
T.J. SAVIDES, C. MESSIN, C. SENGER, Natural Light Exposure of Young
Adults, Physical Behaviour, 1986.
M. TERMAN, J.S. TERMAN, F.M. QUITKIN, Light Therapy for Seasonal Affective
Disorder: a review of efficacy. |
