We just installed a solar tube for a client in a Brooklyn brownstone. Brownstones tend to be dark. So we are big fans of solar tubes. As a solar tube installer there is nothing more satisfying than installing one in a Brooklyn brownstone. The results are so drastic.
We passed this particular solar tube through the floor above and to the roof so it was about 12 feet long.
The pictures below show the tube with an overcast day but the light coming through was blazing. You save so much on electricity. And the light is much nicer since it is sunlight.