Halogen Infrared Ruby Jacket HH451
Aside from their primary application in industrial heating and drying, the original infrared quartz lamps were also trialled for spaceheating. Although small radiant heaters had been employed in domestic situations, most rooms were heated by convective methods to first heat the air, then indirectly warm the occupants. In spaces with high ceilings this is inefficient since the hot air rises above the occupants. Infrared lamps then become more efficient since their radiation passes through the air without absorption, and is absorbed directly by people and objects in the light path.

High power IR lamps also produce a great deal of light, and the high levels of glare limited this application. Traditional red glass filters and coatings could not be applied as with lower power lamps, as the quartz surface temperatures were far too high. Westinghouse was the first to attack this by flamespraying its quartz lamps with orange iron (III) oxide pigment, but this still transmitted a lot of light and absorbed too much infrared. In 1963 Corning developed Ruby Vycor 96%-silica tubing for use as a halogen lamp envelope, but this was prohibitively expensive as both the ends and the inner surface had to be kept free of the red colour dopants. Some lampmakers tried to fuse short lengths of quartz to the ends of these tubes, but that was also difficult since the ruby quartz does not become soft enough upon heating.

It was not until the mid 1980s that the first commercially viable ruby quartz lamps began to appear, and the IR Spaceheating business be exploited. The development of these lamps is attributed to Alex Halberstadt of Thorn Lighting Enfield, one of the pioneers of IR spaceheating and to whom a patent was granted for the design of this lamp.
Manufacturer: GE-Thorn
Lamp Power: 1500 Watts
Lamp Voltage: 235 Volts
Lamp Current: 6.38 Amperes
Cap Type: SK15 + U-Terminals Teflon Cables 230mm
Bulb Type: T-22 T-7 in eighths/inch
Bulb Finish: Ruby Jacket Doped Vycor
Filament Type: C-8 Single Coil Axial
Lighted Length: 260mm 101/4 Inches
Atmosphere: Argon 0.1% Hydrogen Bromide
Luminous Flux: 230 lumens
Luminous Efficacy: 0.15 lm/W
Luminous Intensity: N/A
Beam Distribution: N/A
Colour Temperature & CRI: CCT: 2500K (Filament) Ra: 40
Chromaticity Co-ordinates: CCx: 0.645 CCy: 0.280
Lifetime: 7500 hours
Burning Position: Horizontal ± 5°
Overall Length: 346mm 135/8 Inches
Factory: Enfield, London United Kingdom
Date of Manufacture: 1992 April Date Code: D2 T675
Original Value:
References: 1) Photoelectric measurement.
2) GE-Thorn Halcion Infrared Technical Manual, 1991 UK.
3) GE-Thorn Lighting Product Data Sheet 93:11:05, 1991 UK.
4) US Patent 3,258,631 - Lamp Having a Colored Bulb - Elmer & Nordberg, Corning Glass Inc - Filed 1963.
5) GB Patent 2,176,587 - Jacketed Linear Lamps - Halberstadt, Thorn Lighting Ltd - Filed 1985.
6) Revolution in Lamps, R.Kane & H.Sell, publ. The Fairmont Press, 2001, pp. 65-74.