Existing fixtures in stairwells are recessed 7" can lights, only 1 per landing, none on intermediate landings. On intermediate landings side of stairwell there is a lightshaft, open to glass skylight above. Far wall of light shaft has 3 wall mounted downlights. All currently lamped with...
I don't believe that DC would give more light than AC. AC voltages are usually given in RMS values, which means that they deliver the same power as a DC system of the same rating, and that the peak voltage is higher (typically by .707). The elements in the bulb do indeed see zeros in voltage...
