Linear bulbs can be easily described as ‘straight’ bulbs for their elongated shape, though retrofit LED or low-energy fluorescent alternatives add extra bulk to their form factor. These bulbs use a double-ended connection and were traditionally the domain of halogen, used as a powerful source of light often in outdoor applications.
Typical linear bulb lengths are as follows: 78mm, 118mm, 189mm, 254mm, and 333mm. Of these, the first three are the more common.
The linear lamp is one form of lighting where LED offers mind-blowing potential for energy savings. Recent award-winning products have been promising over 95% reductions in wattage over halogen equivalents. For example, a 7W LED linear lamp can replace a 300W halogen. The vastly longer LED lifespan adds to this advantage considerably in terms of reduced maintenance, and being a solid-state form of light an LED is further suitable as a shockproof form of outdoor lighting with reliable cold-temperature performance.
Linear bulbs are used in many outdoor flood lights, security lights, landscape lights, car park lights, and some indoor flood lights. Though these lamps traditionally delivered a warm-coloured light, the introduction of LED and low-energy fluorescent alternatives into the market allows the possibility of cooler-white floodlights all the way through to a 6400K daylight illumination. These cooler lights make a good choice of exterior work light, since they tend to promote a human reaction of greater alertness and concentration.