Retail

 

The selection of the right lighting can be a major contribution to retail sales. Lighting can establish a store's image, lead customers inside, focus their attention, make the products attractive and visible, and in general encourage purchasing.

 

"Energy Effective" lighting provides all these benefits for the lowest lifecycle cost, while saving energy, operating costs and maintenance. Retail lighting must have good color, contrast and balance between lighted surfaces.

 

Color and spectral content of light sources. There are two common ways to describe the color of light from a source: correlated color temperature (CCT) and color rendering index (CRI). Both metrics should be considered when evaluating light sources.

 

Correlated color temperature, measured in degrees Kelvin (K), refers to the temperature of a blackbody radiator emitting light of comparable color. The scale may seem intuitively backward: The higher the color temperature, the “cooler” or bluer the light. The “right” color temperature for an application may depend on the foot-candle level being maintained. Using lamps with high color temperature at low light levels makes spaces appear cold and dim. Conversely, using lamps with low color temperature at high levels of illumination will make a space look overly colorful. It is particularly important to consider this in dimming applications, because a light source that looks good at 50 foot-candles may not look as good at higher or lower illuminances. This issue is especially important in retail stores and restaurants, where the appearance of objects, people, and food is very important. Another important consideration in selecting an appropriate color temperature is the presence of daylight. For spaces that are day lit, 5,000 K may be the most appropriate CCT.

 

Color rendering index, measured on a scale of 0 to 100, describes the ability of a light source to render a sample of eight standard colors relative to a reference source. A CRI of 100 means that the source renders the eight standard colors in exactly the same way that the reference light source renders the same colors. CRI is an average value, so it will not describe how a light source renders a specific color. However, in general, high-CRI light sources render colors better than low-CRI sources. A CRI of 80 or greater is considered by the industry to provide excellent color rendering.