Blog 8- Electrical Systems and Lights

 This week in Building Systems we learned about Electrical Systems and Lighting. Almost all electricity is provided through power companies, which is generated from several sources, that is mostly used for lighting. Lines carry this energy either underground or overhead with the help of transformers.  

Electrical systems require cables through which the energy can travel within a building. Users then access the energy through outlets or light switches on the wall, now a days light can be turned on and off by remote control, voice activation, or even motion and daylight sensors. Within a system there are many different symbols that are used to help electricians and engineers.  

As interior designers we are somewhat responsible for creating good lighting design. If a lighting design is done well, it will impact energy efficiency and sustainability of a building. One common mistake is to over-light a space, because less lighting used means less air conditioning is needed.  

Lighting behaves in different ways depending on the surface that is it reflects, refracts, transmits, diffuses, or a combination of the above. Additionally, the psychology of lighting is how people perceive different types and levels of light. Good lighting can improve working performance and being able to have control over the lighting can increase employee satisfaction.  

The different types of light are lamps, fixtures, and luminaire. Lights can either be incandescent or fluorescent. Incandescent lighting is primarily used in residential buildings. They give off a warm appearance, can be dimmable, and are relatively inexpensive. However, they can be inefficient and give off more light than heat. Halogen is a type of incandescent light, which gives more of a warm-white appearance, has a strong focused beam, and is often used to illuminate displays or artwork. Fluorescent lighting is primarily used in commercial buildings, they are energy efficient and economical. However, when disposed of they can emit mercury, and both the lamp and ballast enter the waste system creating more trash.  

High energy discharge often occurs in both indoor and outdoor applications such as parking garages and street lighting. Light emitting diodes or LED is an energy efficient solution lighting that lasts a long time, however, is causes color inconsistency.  

When it comes to color there are a few different considerations. Correlated Color Temperature or CCT is measured in Kelvin, a higher CCT creates a cooler appearance while a lower CCT creates a warmer appearance, comparing white light to sunlight. Color Rendering Index or CRI measures the ability to render color, which is rates on a 100-point scale (100 being the best), this is compared on and 8 color reference. Chromaticity chart is a range that most people are comfortable with.  

When picking a light, you must consider the type, size, and the watts. When buying a light fixture there should be cut sheets, which include information like the construction, electrical requirements, operation, etc.  

When thinking about sustainability in lighting designs you must be aware of many things. Lumens per watt or LPW is the energy needed to produce light output in lumens. Light trespass is when light from one building spreads to an adjacent building. Light pollution is light that is directed into the night sky which disturbs wildlife. International Dark Sky Association or IDA is an organization that is seeking to halt environmental light pollution. And Universal Wast Rule requires companies to recycle fluorescent and HID lamps. The Green Seal has specific recommendations, depending on the type of building, they advise compact fluorescent, high intensity discharge, or linear fluorescent lights.  

Automatic sensors harvest daylight and vacancy sensors automatically turn off when a space is not being occupied. Lighting Metrics deal with photometry (the science of light); luminous flux, intensity, and exitance, luminance and illuminance (which are the 5-lighting metrics to quantify lighting).  

There are three different ways to calculate the number of light fixtures within a space, the simple lumen method, the watts per square foot method, and the most accurate, the long lumen method. However, a computer can also complete these calculations.  

When picking lights for a design you should identify each space and its task, the number of foot candles, the best lamp type, keeping consistent luminaires, doing lumen calculations, analyzing daylight within the space and the need for artificial lighting, creating solutions for handling and managing daylight, doing a lighting layout, creating a 3-D model to study disturbances, and designing special lighting effects.

Overall, there are a lot of different steps and considerations when picking a lighting design. There is programming, schematic design, design development, and construction documents. As designers, you must make sure that the contractor and his workers know exactly what to do, so a lighting plan, specifications, design details, and graphic standards should be provided. A lighting plan is also called a reflected ceiling plan, which has the same layout as the ceiling plan but simply only shows the light fixtures and walls (possibly windows and doors).  

Blogging Assignment:

Here are the two pictures I chose because of their different lighting options and the shadows that they create. I chose to shade in the second photo because it had more distinct shadows and contrast in general. I learned that lighting can have a big effect on how you perceive a place. The second picture has both bright areas due to the sunlight and darker hallways because the distance of the lighting and lack of windows to outside. The exterior courtyard seems very inviting and calming, while the hallways seem a bit ominous and is uninviting. While shadows add interest and contrast to an area, too many shadows can darken both the environment and people's moods. It is important to add the perfect amount of lighting to have the right amount of light, avoid over or under lighting and overall a space that people want to enter.