The common-a-garden ‘General Lighting Service’ lamp was traditionally a regular incandescent bulb - widely used commercially and domestically in everyday fittings - although usually a little more robustly constructed for the industrial arena and dubbed a ‘rough service’ GLS lamp. It is still possible to buy these bulbs in their rough service guise, but you might want to consider for a moment the idea of an eco halogen replacement that will consume 30-40% less energy than their old-fashioned rival, as well as lasting twice as long. That’s a tangible return on any extra investment you might make.
For the same wattage an energy-saving halogen GLS bulb will produce a greater output of lumens over incandescent; it has a superior lumens-per-watt measurement. Both technologies being incandescent at heart, they abide by the black-body radiation theory and produce a continuous spectrum of light. That makes them easy on the eyes – natural - and extremely colour accurate.
The positives over incandescent technology have already been proven, but how does the energy-saving halogen fare against fluorescent (aka CFL or energy-saving) bulbs or LEDs? Well, it lags behind them by some way both in terms of longevity or energy-efficiency, but the halogen GLS is much cheaper, too, and will give you 2-3 years of service for a price that doesn’t elevate much above a traditional incandescent.
There’s the quality of light, as well: nearly all incandescent bulbs hit maximum 100CRI colour rendering index scores, whereas the newer kids on the block puff and pant just to be anywhere near the same ballpark. Mostly they don’t make it. That’s doing them a bit of a disservice - they’re tough competitors overall and can save a veritable fortune for a business, but halogen has a part to play where sheer quality of light and critical colour representation wins over running costs