Fluorescent lamps: Visual and thermal comfort in modern interiors

Air conditioning's impact on the modern office interior was immediate and profound but lost in historical concentrations on thermal comfort has been the importance of fluorescent lighting. Fluorescent lamps andfixtures were key components of what Reyner Banham called "power-membrane ceilings," key counterparts to the glass curtain walls of the 1950s and 1960s. Fluorescent lamps relied on 19th century advances, but they were spurred on by the expiration of incandescent patents in the 1930s. Keen to find new markets to corner, General Electric and Westinghouse developed commercially viable lamps that offered greater electrical and thermal efficiency. Avoiding the heat gain of incandescent lamps, however, was only part of fluorescent lamps' impact on thermal comfort. Their cool operating temperatures allowed the use of easily-formed plastics to house them, leading to reflectors and diffusers that distributed or focused their light with precision. Fluorescent lighting's success can be measured by the evolving standards for light levels-which leapt from 3-4 foot-candles (32-40 lux) for clerical work in 1918 to 100 foot-candles (1,000 lux) in I960. This matched air conditioning's influence on comfort standards as well as its ability to homogenise office floor plates, tuning light levels to tasks below and adding regimented, gridded order to open plan office floors.