Converting fluorescent tubes T8 to T5

* This section will be expanded *

1. Background

Fluorescent tubes are in popular use, and have provided inexpensive hassle free lighting for industrial & commercial sites for many years.  Owing to their initial high level of efficiency, it has taken a lot longer for alternatives to become available, and the level of improvement provided has often been marginal or required significant project management.

2. What exists in most industrial and commercial ceilings today ?

Today, most sites that use fluorescent tubes employ a recessed dual tube fitting that typically features a hidden iron core transformer / inductor (‘gears’ or ballast) inside the fitting, combined with a starter unit and two 36 watt tubes (the diameter is normally T8 or T12 size – T12 is just 12 x 8ths of an inch). More modern types include an electronic starter rather than an iron core ballast – this reduces consumption of the ballast component and avoids the starter, plus provides some benefits in terms of lamp longevity and brightness.

3. What are the alternatives?

There are several alternatives to the situation apparent in most offices today, these are:

  • De-lamping or Re-circuiting – removing lamps from low traffic areas, removing tubes from ‘over lit’ areas, and re-circuiting to ensure lamps are grouped together in smaller groups, so that the light pattern / layout can be made to match the occupancy pattern / layout.
  • Replace T8 lamps & starters (36W for tube, 10W for ballast = ~46W) with a T5 converter kit (28W)
  • Replace T8 fluorescent tubes with LED tubes.