Well Gents, you can thank our hero in the whitehouse because it won't be long and you will replace your T12's or live in the dark. He has obsoleted them to SAVE YOU, energy and pollution. One major reason they do not do well in low temp situations is because they contain mercury. The mercury condenses into droplets when the lamp is off and cold. Ever notice how they swirl and flash when you turn them on? Then after they warm up they calm down and get brighter because the mercury has ionized again and remixed with the other gasses in the lamp. Tubes with GREEN ends are a version without mercury but are not as color corrected or efficient. You really can't tell unless you have light meters and other test devices.
T8 and T5 lamps are the wave of the future. They show a lot of promise but only time will tell if they are a good replacement.
Your shop lights burn out because you buy them at the home fix-it place and they are junk. Cheap and junk. If you spend more and buy a UL approved, quality name fixture your burn outs will all but disappear. Defective light fixtures will show themselves in the first 30 to 60 days while under warranty, and if contractor installed labor is free too. Properly maintained commercial lighting works like this. In four years of average burn time, you re-lamp every fixture in the place and clean the fixtures. Unless the light is in a critical location, if it quits working you fix it on the four year maintenance cycle. This way you are not messing around all the time. After you re-lamp you will be amazed at the difference in lighting level. Remember, 4 years or 25% drop in lighting level. It's what the pros recommend.
Lights that are not switched do last longer. Some more than others. Why? Because you are not shocking the lamp filament by going from room temperature to brilliantly white hot in nano seconds. When you buy lamps don't buy the grocery store specials and the bargain packages. Buy lamps with the highest voltage rating you can find. Severe service, rough duty, traffic signal, are other key terms to look for. Reason: In these type lamps, the part that does all the work, the filament, is made from a larger gauge wire and has more supports so it does not droop, sag, and stretch while it its white hot almost molten state. Hence-longer life.
On the above post, yes in some cases you may do as he suggests. Watch the height of the lamp holders. Florescent lamps must have a grounded metal reflector mounted within a certain distance away from the full length of the lamp. How far? I am not sure but I do know that if the distance is too far you will get short lamp life or they won't work at all. The fixtures I am around are built correctly from the get go so I never have to think about this detail.
