Window Film Reduces Light Pollution

Window film can reduce light pollution.  Depending on the type of film, Visual Light Transmittance can be reduced by 45%-50%. According to Global Trends and Implications for Downtown Denver, a paper prepared by Progressive Urban Management Associates in 2006, 3 billion people lived in cities and by 2050 6 billion people will be living in cities.  The implications for energy consumption, transportation, food, and environmental protection caused by this rapid urban expansion makes the need for sustainability  critical.

The management of artificial light is one of the many areas urban planners must prepare for.

Light pollution causes:

• Sky glow which is the light surrounding the urban skies is caused by over illumination of commercial spaces and poorly planned street and building lights. The stars are difficult to see in urban areas.
• Light trespass is the light from a building shining into another building.  It may be difficult to sleep in an apartment building next to a building that has a lot of light during the night.
• Endangerment to wildlife who are confused by the light.  Nocturnal animals do not hunt or mate as they are meant to.  More animals are in danger of becoming extinct.
• Human health is being affected.  Vision, headaches, hypertension, and an increased chance of developing cancer are some of the health issues.  Sleep is disrupted by the light and melatonin is decreased. (physics.fau.edu/observatory/lightpol-environment.html)

There are things that city planners and all of us can do to decrease light pollution.  One of them is to apply window tint to windows that meets 45% inside to outside visible light transmittance and/or use window treatments.  On a beach in Florida, new construction is required to put in windows that meet the 45% requirement because sea turtles are confused by the light and go inland instead of going out to sea.  People that already have homes are helping to save the turtles by retrofitting their windows with window film to meet the requirement. (Thisbigcity.net)

Window film meets LEED Certification requirements in this area and is worth 1 point toward building certification.

Credit 7:  Light Pollution Reduction (1 point)

Intent: Eliminate light trespass from the building and site, improve night sky access and reduce development impact on nocturnal environment.

Denver is a city that is at the forefront of working to make sustainable urban environments.  Denver is also experiencing rapid urban growth.  The challenges in keeping up with all the facets of urban growth is being met by our city leaders and urban planners with great care.

Colorado 2nd Place in LEED Certification

The state of Colorado achieved 2nd place in LEED Certification.  Congratulations, Colorado!  A new report by the US Green Building Council reported recently the top ten states with the highest ratings.  The rating system calculates the square feet of the space that is LEED certified and divides it by the number of residents that live in the state.  The measurement is a way to indicate how states are moving toward green building. Illinois was rated number 1 gaining a score of 3.3.  Colorado received a rating of 3.2.  Illinois and Colorado are the only 2 states that have been in the top 10 over the past 5 years.  This type of measurement began by the US Green Building Council 5 years ago.  If it were a state, the District of Columbia far surpasses the ratings of any of the states. (www.tripudit.com/2015/02)

LEED is used throughout the world to evaluate green building systems.  The top rating is a Platinum rating. There is also a Gold rating.  A Silver rating has recently been included so that more buildings can be rated at a lower cost.  LEED certified buildings use less energy and water, reduce carbon emissions, save money, and create a healthier environment.  There are a lot of things that builders have to do to acquire points for this ratings. This information is available on the USGBC website.

A few of the buildings in Denver which have received a platinum rating are:  1800 Larimer, NREL Research Support Facilities, Signature Centre, and Williams Village at the University of Colorado.  A list is available on the web.

Energy Savings with Window Film

Energy savings can be obtained with the use of window film.  Window film reduces the amount of heat that enters a room.  Less energy is required to cool the room.  In the winter, the film acts as an extra insulation on the window, reducing heating costs. LEED credits can be obtain by using window film.  The number of points that are obtained, depend on the amount of energy saved.

The goal of this credit is:  Achieve increasing levels of energy performance above the baseline in the prerequisite standard to reduce environmental and economic impacts associated with excessive energy use.  (www.3M.com/windowfilm)

There are 3 different methods for achieving this requirement.  Up to 10 credits can be obtained depending on the amount of energy savings. For specific information on the methods see the sustainable design information sheet in pdf form on the 3m web site:  multimedia.3m.com/mws/media/6636910/sustainable-design-information-sheet.pdf

Window film is a first tier technology that can have an approximate 3 year payback for buildings.  Window films are ranked in retro-fitted building envelopes as having the highest probability of success.  It ranks above replacement windows. Already existing materials are used decreasing the amount of waste. (https://promo.3m.com/assets/3MCAN/1202511082.pdf)

3M Daylight Redirecting Film

At the 3M Conference in Puerto Rico, 3M introduced its new product 3M Daylight Redirecting Film, which is intended to help create green buildings.  The 3M Daylight Redirecting Film uses micro-replication to redirect the light that would have originally hit the floor a few feet from the window.  The light is directed to go up to the ceiling and then be reflected off the ceiling to light the room as far as 40 feet from the window.  About 80% of the light is brought into the room.  This reduces the need for artificial light during the day.  The natural light coming into the room increases productivity, people buy more, and reduces the need for electric lighting.  This energy efficient new window film technology can be used in retrofitting as well as new construction.   It is generally a commercial window film. The Daylight Redirecting Film is installed on the south, east, and west facing windows and is installed above a sill height of 6 feet to keep the sunlight out of the eyes of the people in the building.  The appearance of the glass with the redirecting film has the appearance of frosted glass.  The window film still keeps out harmful UV rays and stops glare and fading.  Some of the same benefits could be gained by putting a shelf on the window frame that reflects the light.  This shelf is not very attractive and is difficult to clean.  The window film is attractive and can be cleaned like any other window.

3M Daylight Redirecting Film will increase the sustainability and tenant satisfaction of a building.  It can be an effective energy management tool.  For specific information on how to use this new technology, contact  a Solar Vision Inc. representative.