With the first day of summer, June 20, 2012, we experience the longest day of the year, the summer solstice, which reminds us of the generous amount of light that comes to us from the sun. And yet, despite the incredible amount of sunlight we have, many of our buildings rely heavily on artificial light.
by Grady O'Rear*
According to the Energy Resources Information Administration, physical lighting is responsible for more than 11% of primary energy consumption in U.S. homes and more than 25% of primary energy consumption in U.S. commercial buildings. 1 Primary energy means the energy consumed during generation at the power plant + the energy used to achieve its transmission to a given site + the energy consumed on site.
Natural lighting, which consists of illuminating interior spaces with natural light from the sun, is the primary ecological strategy used to reduce energy consumption requirements. By accessing free sunlight, energy savings are achieved with natural lighting by reducing artificial lighting and thanks to heating or passive solar cooling. The benefits are for both residential and commercialconstructions 2.
For example, total energy costs in institutional and commercial constructions can be reduced by a third if there is optimal integration of daylighting strategies. 3 In offices, natural lighting with light regulators has been shown to reduce energy needs by a quarter. 4
In addition to the considerable opportunities for energy savings, lighting has a profound influence on the enjoyment and healthiness of the interior space. It can affect mood, comfort, and stress levels.
In retail stores, natural light not only illuminates the shopping environment, but research has also shown that it increases sales per square meter. 5 And in schools, studies indicate that it improves learning rates and test scores. 6 In offices, daylighting has been correlated with significant increases in productivity, sometimes outpacing the energy savings achieved. 7
Humans respond positively to natural light. It helps our bodies produce vitamin D, influences our sleep-wake patterns, promotes hormone production, and adjusts circadian rhythms.
Conversely, lack of exposure to natural light is associated with a form of depression known as Seasonal Affective Disorder (SAD). It is estimated that this disorder affects, to some degree, about 10% of Americans. The disease, sometimes referred to as "winter depression," poses an increased risk to those living far from the equator, due to the shorter duration of days in late autumn, winter and early spring. The main treatment for SAD is, as you can imagine, light therapy.
Natural light: a fundamental feature of bioclimatic architecture and design
Bioclimatic design is an integrated approach to building design and construction that considers the building enclosure as the primary heating, cooling and lighting device. It deals with "designing and building with nature" in order to minimize the need for mechanical and electrical components.
In bioclimatic design, natural light is the most important lighting source, while artificial light is a backup of daylight. By locating, orienting and constructing the enclosure, door and window openings, light distribution strategies and other physical features of the building in harmony with the sun, wind, water and land, the comfort of the occupants is improved, while energy resources can be obtained more fully at no cost.
Artificial light: support of natural light
Described below are some of the healthy and energy-efficient options for different types of artificial lighting and lighting regulators. It is important to note that the purpose of the lighting is in accordance with the appropriate bulb or dimming device. To make sure of this information, look at the label of the bulbs:
* The luminosity of the bulbs is measured in lumens
* The appearance of light is described on a scale ranging from colder to warmer
* Full spectrum lights are designed to emulate natural sunlight
* Energy-efficient artificial light devices are Energy Star certified.
Tubular lamps
T-12 (11/2" diameter) fluorescent lamps can now be replaced by thinner T8 (1" diameter) and T5 (5/8" diameter) lamps. These lamps provide more efficiency, higher intensity and a potentially longer service life.
They are also useful in different applications in selective lighting for work areas and in detail lighting, as well as in general lighting of large spaces. Tubular lamps contain mercury, so it is recommended to dispose of them in local recycling facilities.
Compact fluorescent lamps
It is not difficult to replace incandescent bulbs with compact fluorescent lamps. These cost more, but replacing a standard 100-watt incandescent bulb with a 32-watt compact fluorescent lamp can mean savings of $30 or more in energy costs.
These types of lamps not only save on energy consumption, but also provide high-quality lighting without the excess heat of an incandescent bulb, and also last up to ten times longer. Compact fluorescent lamps also contain mercury, so again, it's important to use local recycling facilities for disposal.
LED lighting (light emitting diode)
In the past, most LEDs were found solely in the form of indicator lights on electronic devices such as televisions and sound equipment. Currently, there are on the market to meet many standard lighting requirements.
Not only do these highly efficient devices last up to 25 times longer than an incandescent bulb, but they can also focus light more accurately than a fluorescent bulb. They can provide optimal color in a wide variety of uses, from parking lots to high-end trade shows. And they don't contain the dangerous mercury.
Electronic ballasts
If you have the opportunity to participate in the specification process, always order electronic and non-magnetic ballasts. Electronic ballasts use up to 30% less energy and allow for scintillation-free operation.
Lighting regulators
Minimizing the use of artificial light is the most efficient measure. Lighting regulators maximize the flexibility of our system, while allowing us to dispense with the unnecessary use of artificial light. The following are some common regulators:
Dimmers
They can be used with fluorescent and incandescent systems. Natural light graders use sensors to automatically adjust the light in the room based on the amount of natural light available. Its use is common in classrooms, conference rooms, libraries, and restaurants.
Occupancy sensors: These are motion detectors that turn on the lights when motion is detected and keep them off when the rooms are not being used. Some of the most common uses for these sensors are in classrooms, cellars, bathrooms, and closets.
Two-level switches: Allow users to control groups of lamps. Thus, depending on the needs of the users, a part of the lights of a room can be activated instead of activating the entire system. Its use is also common in classrooms, offices and warehouses.
1 United States Energy Information Administration. (October, 2008). Energy Efficiency Trends in Residential and Commercial Buildings. Retrieved October 20, 2011, http://apps1.eere.energy.gov/buildings/publications/pdfs/corporate/bt_stateindustry.pdf
2 U.S. EPA. Green Building (December, 2010) Obtained on June 17, 2012 from http://www.epa.gov/greenhomes/ReduceEnergy.htm
3 Ander, G. National Institute of Building Science. Daylighting. (August 29, 2011). Retrieved October 18, 2011, www.wbdg.org/resources/daylighting.php.
4 Figueiro, M. et. al., Daylight and Productivity – A Field Study. (2002) Retrieved June 20, 2012, http://eec.ucdavis.edu/ACEEE/2002/pdfs/panel08/06_15.pdf
5 Daylighting and productivity. (2011). Retrieved from Heschong Mahone Group, Inc. website: http://h-m-g.com/projects/daylighting/summaries%20on%20daylighting.htm
6 Daylighting and productivity. (2011). Retrieved from Heschong Mahone Group, Inc. website: http://h-m-g.com/projects/daylighting/summaries%20on%20daylighting.htm
7 Save the Bulbs. Daylighting and Productivity. (2005) Retrieved June 19, 2012, http://www.savethebulbs.org/productivity.html.
*The National Hispanic Building Association (NHCA) has asked Green Advantage to collaborate with a column for this space. Grady O'Rear is president/CEO of Green Advantage, a national certification body for builders – www.greenadvantage.org. To contact him, write to [email protected].
NHCA NEWS
Second annual NHCA conference: "Building from the ground up"
Date: Thursday, September 27, 2012
Time: 8:00 a.m. - 2:00 p.m.
Location: Marriott Wardman Park Hotel - Washington, DC
The 2012 National Hispanic Building Association (NHCA) conference, "Building from the Ground up," will provide minority contractors and subcontractors with the tools needed to have a competitive and successful construction business.
The event will include presentations from major general and regional contractors, construction managers, government agencies and service representatives on topics such as: contracting advisory programs, size standards, federal contracting, marketing and business positioning and many others.
More information soon!
Prevent falls in construction and save lives
Falls are the leading cause of death in construction. In 2010, there were 264 deaths from falls (255 falls to a lower level) out of a total of 774 deaths occurring in the construction sector. These deaths could have been prevented.
As the highest season for construction approaches, it is important to remember that this sector is where more deaths occur in the country and falls represent the deadliest risk in that sector.
The figures speak for themselves: in 2010, more than 250 workers lost their lives to falls on construction sites, while more than 10,000 workers suffered serious injuries. The Occupational Safety and Health Administration (OSHA) is responding to the societal call to avoid unnecessary deaths with a national campaign to prevent falls.
The effort promotes three simple steps for workers and employers to follow: Plan, Provide, and Train. More information can be found on OSHA's fall prevention website, in both English and Spanish, with resources to help ensure that any work done at height is carried out safely.
"By sharing this vital information we can save lives," said Dr. David Michaels, OSHA's assistant secretary of labor. We can make the promise that all workers deserve to return home safely at the end of a workday a reality."
Eco-friendly heating, ventilation and air conditioning: top priority
CVAC systems are a fundamental component of the operation of most constructions. Indoor Environment Quality (IEQ) influences, in many cases to a great extent, the health, comfort, productivity and learning of occupants.
In addition, CVAC systems have significant energy consumption requirements. In the United States, 37% of the energy used in commercial construction is used to acclimatize spaces. And in residential constructions, heating and cooling of spaces represents 54% of energy consumption.
An environmentally friendly handling of a building's heating, ventilation and air conditioning needs has many advantages that can improve the quality of the indoor environment, decrease the value of energy bills, increase equipment life and reduce claims. Designing and building in harmony with nature can drastically reduce the requirements of CVAC systems.
Depending on the climatic zone where the construction is located, the implementation of several strategies for energy efficiency in the enclosure of buildings can drastically reduce the loads involved in heating and cooling systems. The enclosure of a construction covers its exterior walls, roof, windows, skylights and other openings, as well as its foundations.
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