When it comes to lighting up a work area, office, warehouse, or garage, fluorescent light bulbs tend to be the ones chosen more often than other types of bulbs. When compared to incandescent lighting, fluorescent lights are longer lasting and use much less energy. For certain applications, a circular fluorescent bulb is the best option. Osram Sylvania, GE (General Electric), Philips, and Westinghouse all produce bulbs from this category.
While circline fluorescent bulbs come in different sizes, the most common type is the T9. This means the bulb is 1 1/8 inches thick. Depending on the wattage, the distance across the entire circle ranges from 6 inches to 16 inches. Often times fixtures will use two of these bulbs in tandem in order to get the most light output from the least amount of physical area. The typical power used for this bulb would be 20 watt (6 inch), 22 watt (8 inch), 30 watt (8 inch, screw-in base), 32 watt (12 inch), and 40 watt (16 inch).
As with all fluorescent bulbs, circline bulbs rely on ballasts inside of the fixtures in order to make them work. Ballasts are available from Universal, Magnatek, Advance, Osram Sylvania, among others. Almost all fixtures for circline bulbs come with ballasts already mounted and wired.
The color temperatures available in common circline light bulbs are 2700K (very warm white), 3000K (warm white), 3500K (warm/cool blend), 4100K (cool white), and 6500K (daylight). Vendors such as Osram Sylvania, GE (General Electric), Philips, and Westinghouse offer several types of circline bulb. One of the enhanced lines is Sylvania's Designer series. These bulbs will provide all the features and benefits of what has already been listed here, as well as an improved CRI or color rendering index. This means your blue jeans with fuchsia top will look more vibrant than under normal circline bulbs. It is a wonderful tool for showcases, art displays, and many other applications that need to show proper and vibrant colors.