I can where the ceiling height is less than the area 12 T5 lamps use? You can use the T5 in this case, but you have to remember that the additional costs associated with T5 fluorescent lamps. But the cost should not be your only factor, so you have to explore the technical aspects to understand why T5 may not be the most appropriate. Standard output T5 lamps, have their place, but understanding the application and expected results. T5 lamps produce the best ambient temperature at 35C (95F) which will make people think they are not doing well in the cold. This is not entirely correct, see the evaluation of environmental temperature using the manufacturer's yes, right bulb air.