CHOOSING THE RIGHT LAMP

Larry Weber, Naturallighting.com Copyright© 2003-2004

Three things must be considered in choosing the right color of fluorescent lamp for a specific application, (1) Color Temperature, (2) Color Rendering Index, and (3) Lumen Output. These factors are independent, and can vary for each lamp.

Color Temperature is expressed in degrees Kelvin (K). For example, noon daylight is about 5500 degrees Kelvin - the same as the full spectrum Vita-Lite. Fluorescent lamps with lower color temperatures look red; fluorescents with higher color temperatures look blue. This makes sense if you imagine an iron bar being heated. First it gets "red hot." Then, as the temperature increases, it becomes "white hot" and finally, "blue white" hot. The color temperature of outside light varies from 5500K to 6800K depending on the time of day, weather, season and latitude. The higher the color of a fluorescent lamp, the bluer (cooler) the appearance. The lower the color temperature the redder (warmer) it's appearance. Color temperatures of standard fluorescent lamps such as Warm White = 3000K, Cool White = 4100K, Daylight = 6500K. The following color temperature chart shows the typical color of light related to Kelvin degrees, and type of lamp with these characteristics.

Color Rendering Index (CRI) is a numerical system that rates "color rendering" ability of fluroescent light in comparison with natural sun light, which has a CRI of 100. Color Rendering Index (CRI) is how the color of an object appears under the artificial light source illuminating as compared to natural outdoor sunlight. This means that a lamp with a CRI of 91 shows colors more naturally than a lamp with a CRI of 62. Most standard "warm white, cool white, and day light" fluorescent bulbs range 60 to 75 CRI. This rating method is recognized by the Illuminating Engineering Society (IES) and the Commission International de L'Eclairage (CIE).

Lumen is the SI unit of luminous flux. Lumens represent the time rate of transferring luminous energy; quantity of light (brightness). One lumen is the light of flux falling on a surface of one square foot, every part of which is one foot from a point source having a luminous intensity of one candela in all directions. All fluorescent lamps have a lumen rating, or brightness. Vita-Lite Plus T8 and T10 lamps have the highest lumen output or are the brightest full spectrum lamps on the market.

It is important to consider three factors when selecting a lamp for a specific task.

  1. Color Rendering Index
  2. Color Temperature
  3. Lumen Output

Color rendering index, color temperature, and lumen output are independent of each other. It is also possible for two different lamps to have the same temperature and yet have a different color rendering index, and lumen output. The lamp with the highest color rendering index will generally have the lower initial lumen output of the two.

One of the first things to consider in determining proper lighting is the application, specific use/task, size of area, ceiling height, and type of fixtures. Most existing areas can be retrofitted with full spectrum lamps without significant change and or upgrade, other than replacement of defective or old ballasts, and diffusers (plastic lens on fixtures).

Ballasts are one of the most important components of fluorescent light fixtures. Ballasts deteriorate over time and loose efficiency. Therefore, if a ballast is operating at 75% efficiency, light output will also be lower. If ballasts are over five to eight years old, replacement is recommended. Standard magnetic ballasts have been used for years, and are being phased out (see our Super-Tek universal electronic ballasts section).

Our Super-Tek electronic ballast offer several advantages over magnetic ballasts - lower electrical usage (10 - 15 watts per ballast, lower heat generated (for every 2-3 watts saved on lighting, 1 watt will be saved on air conditioning costs), longer life (5 yr. warranty, fewer number of ballasts, 50% dimmable with standard dimmer switch (Super-Tek only), longer lamp life - up to 30% more, higher light output with high ballast factor of 1.3, fewer number of ballasts - one ballast operates up to four lamps. Super-Tek ballasts operate up to 17 different lamps, which results in a significant reduction in inventory costs. Don't have to stock several different ballasts. One ballast does it all.

The following chart is a summary of typical applications and recommended lamps. We offer free consultation for optimum lighting, please call 888.900.6830. We will recommend the most optimum lighting for customer needs (size of room, ceiling height, intended use, type of fixtures, reduction in energy costs).

The right light is very important to enhance work and home environments. Changing out light bulbs can improve home and work areas significantly, reduce eye strain, glare, fatigue, increase productivity. Many customers report feeling better; can work longer; reduces eye strain and glare, pets are healthier and increased reproduction, plants grow better, etc., with our full spectrum lighting.

Color Temp/Kelvin Associated Effects
and Moods
Applications
Daylight, Color Classer 5900-7500K, 85-91 CRI Bright, Alert, North Blue Sky Appearance (Blue Tone) Galleries, Jewelry Stores, Museums
Vita-Lite, 5500K, 91 CRI Natural Outdoor Light, Hight Color Rendering People, Plants, Pets, Offices, Schools, Retail Stores, Medical/Dental Facilities, Factories, Artists, Graphic Industry, Printing, SAD (Seasonal Affective Disorder)
Optima 50, 5000K, 91 CRI Neat, Clean, Efficient Graphic Industry, Photography, etc.
Aurora V, 5000K, 85 CRI Neat, Clean, Efficient Offices, Schools, Factories, Retail Stores, Photography, Graphic Industry, SAD, etc.
Optima 32, 3200K, 82 CRI Friendly, Inviting, Non-threatening Public Reception Areas, Showrooms, Offices, Film Industry
Aurora III, 3000K, 85 CRI Friendly, Intimate, Personal, Exclusive Restraunts, Hotel Lobbies, Botiques, Office Lobbies