Saving energy matters Most office buildings use fluorescent light fixtures containing three to four long tubular bulbs each. The bulbs are designated T5, T6, T8, etc with the T indicating that the bulb is tubular, and the number indicating the bulb's diameter in eighths of an inch.
目前一般辦公大樓使用 3-4 支一組的直線形長燈管，也屬於「緊湊型螢光燈」的一種，它們因管徑大小有 T5、T6、T8 到 T12 之分（T 指直管，數字代表管徑英吋大小）。