@hawkeye10,
Quote:I assume that the efficency of this heat is not ideal
The efficiency at the bulb envelope is perfect, ie. 100% efficiency.
I've never seen any data that breaks down each kwh used for incandescent lighting into heat/light production.
I wonder what the changes were that Joe mentioned that allowed more lumens with less wattage.
The inefficiencies come from making and distributing electrical energy to houses.
After the bulb envelope, any inefficiency is from getting the heat to the place where it's needed, which, as Roger pointed out, isn't all that crucial considering the massive volume of heat that's needed to heat a house during winter temps, [actually it's the wusses' heating needs, not the houses] and the minimal amount of heat put out by a 100w bulb.
Probably the greatest inefficiency relating to residential heating and cooling are those who, immediately upon feeling cool or warm, turn up or turn down the thermostat.