This week I finally got tired of my fluorescent lights not working or barely working in the winter. First I tried rebuilding the exsisting lights with new electronic ballest & T8 bulbs. Unfortunately the ballest had a ballest factor of 88% which was 25% less than the originals. This equated to 25% less light, but they turned on in the cold /forums/images/graemlins/tongue.gif. I took those back and bought two new 8' High Output fluorescents lights at Home depot for $45 each, bulbs were $7ea x 4. The 8' H.O. lights throw out a tremendous amount of light, another 30% over a standard 8' fluorescent shop lights and have the -30F start temp. I believe they are 90 watts each, so all four use 360 watts, which isn't too bad for an area this size.
Last night I hung two of these in the rafters 14' up for an area about 28' x 28'. It's like outside daytime in there now. They are instant start, but I've noticed they reach peak brightness in about 3-5 minutes in the cold. In the first couple of minutes, the light is slightly pinkish, but becomes a bright white. Previously I had (4) 4' double fluorescent lamps, which were not nearly as bright.
Now I'm thinking the rest of the barn will eventually get these.
Tim