Green Means

Comfortable Indoor Environments

By Shannon Scott

            I mentioned two weeks ago that indoor environmental quality (IEQ) encompasses indoor conditions needed for human health and comfort.  I discussed two factors affecting indoor comfort: clean, fresh air, and comfortable room temperatures.   Now let’s take a look at two more IEQ factors – lighting and views. 

Lighting Design

            Daylighting helps create a visually stimulating and productive environment for building occupants, while reducing as much as one-third of total building energy costs.  Natural daylight makes interior spaces feel better, illuminates more clearly, saves massive amounts of energy, and makes people feel good.  It is human nature to want to connect with the outdoors, so placing windows where people can gaze out and allow natural daylight in makes for a pleasant environment.

            Lighting is the largest energy use in most commercial buildings.  Many work places have little natural light entering windows so that artificial lights are on full force during mid-day hours.  Some houses suffer the same natural light anemia, raising energy costs unnecessarily.  Artificial lighting proves another barrier between humans and the natural world, which makes for us not feeling well in our daily environments. 

            When homes and commercial buildings are designed to make use of natural daylight to illuminate interior spaces without summer heat gain, blinding sun, or annoying glare these interior spaces feel better and are more pleasant in which to live and work.  Lighting makes spaces feel good or function poorly, and affects the overall sense of space.  Darker rooms often feel smaller than brighter ones.  Rooms that are too bright prove tense and feel industrialized.  

Architectural Products Magazine noted daylighting study results in schools and retail buildings:

·       Daylighting has proved to increase per transaction value in retail store settings.  Customers stay in the store longer.

·       Full daylighting enabled students to get more vitamin D than students in schools with primarily electric lighting.  These students’ had nine times less dental decay and grew nearly an inch more in height over two years. 

Sidwell Friends School lighting schematic showing natural daylighting options

            Windows, sky lights, light shelves, and solar tubes are a few ways to bring beautiful natural light indoors.  For existing buildings, adding traditional style, energy efficient sky lights and/or tubular sky lights may be the cheapest and most effective addition for improving IEQ lighting.

            We all need to use artificial lighting when natural light is dim or non-existent.  Some artificial light choices are better than others.  There are books and free videos available on line, put out by lighting manufacturers, the American Lighting Association (http://www.americanlightingassoc.com/Lighting-Fundamentals/3-Types-of-Lighting.aspx) and others explain the three main types of lighting: ambient, task, and accent.  Nicely lit homes use a combination of all three. 

            Best choices in artificial lighting are always low energy use fixtures, and long lasting bulbs. Compact fluorescent lights (CFL), high density discharge (HID), and light emitting diodes (LED) all emit more light with less electricity then incandescent lighting.  CFLs emit the same light as incandescent using 70-80% less electricity.  While these bulbs contain trace amounts of mercury the mercury criticism is overblown.  CFLs, typically, have about as much mercury as eating a can of tuna fish.  

            Lighting controls also make a huge difference in energy conservation and human comfort.  Photosensors monitor daylight and auto-adjust the amount of light needed.  These may work great if they can be manually adjusted as well.  Timers are good in some situations, especially commercial buildings, but need manual overrides so if people go into work during off hours they can control the lighting.  Occupancy sensors which have been common for some time, can also tie into HVAC thermal controls to turn on or off heating or cooling only when buildings or rooms are occupied.   All of these lighting methods make people feel better in their environments, increase productivity, and save energy use and costs.

Views

            An obvious hand-in-hand benefit of natural daylighting is having views out windows.  People feel better, whether at home or work, if they can gaze out and see a tree, park, wild life, or somehow get a visual connection with the natural world.  Views into brick walls, streets, asphalt, and other buildings do not make people feel good and do nothing to contribute to work place productivity. 

Young Children's Relationship with Nature: Its Importance to Children's Development & the Earth's Future, by Randy White documents studies showing that:

·       Children with views of and contact with nature score higher on tests of concentration and self-discipline. The greener, the better the scores (Faber Taylor et al. 2002, Wells 2000).

·       Exposure to natural environments improves children's cognitive development by improving their awareness, reasoning and observational skills (Pyle 2002).

·       Nature buffers the impact of life stress on children and helps them deal with adversity. The greater the amount of nature exposure, the greater the benefits (Wells 2003).

            People think better and perform tasks more efficiently when they feel good – so it’s time to design homes, schools, and businesses – any building we inhabit - with this in mind.