Gluh lampe: The Last Gasp for the Incandescent Bulb
by Lloyd Alter, Toronto on 10.26.06
This might just save the incandescent bulb from oblivion: The gluh lampe picks up the heat energy produced by the light bulb and warms the clay brick, which radiates for up to an hour after switching off the light. The brick tone makes the quality of the light even warmer, and "the brick can easily be disconnected from the bulb and can be used as a bed-warmer, just like in granny's times." You are not wasting all that energy, you are taking it to bed. 79 Euros (US$ 100) ::Formfjord via ::Design Spotter
a brick for 100 dollars? honestly?
The heat output from an incandescent bulb is useful for heating regardless of whether a brick is around it. The "waste" heat isn't going to disappear without the brick to absorb it. The heat will heat up the air and nearby walls without any help from a brick.
The problem with incandescent bulbs is that they output heat whether you want heat or not.
So in hot weather they make the indoor environment worst. If we only used incandescents during the winter they would be an excellent method of lighting.
Heat rises. With a legacy (incandescent) bulb positioned above your head you are basically just heating the ceiling... so I doubt the use of legacy bulbs for purely heating purposes.
Heated air rises whether it's coming off an incandescent bulb or out of a floor register.
The bulb is radiating in all directions - floor, walls, ceiling. Heating a brick with this radiant energy changes nothing, the brick just reradiates the light as in all directions ( as purely infrared light) and you lose some of the usable light. You could put a reflective cap on the bulb to reflect the light/heat only downwards. In any case, some of the bulb's radiation heats up the air directly and the rest heats up the room's surfaces, which then reradiate the energy outwards and heat up the air. And so on.
After the heated air rises to the ceiling the ceiling heats up and reradiates the heat down as radiant energy. But it's true that ideally you don't want to heat the ceiling or any exterior walls too much as some heat leaks out from the other side of the ceiling or wall and is lost. That's why ceiling fans can be a good idea in some homes, regardless of the heat source location - they keep the ceiling from getting too warm and redistribute the heated air better.
Think of light bulbs as electric resistant heaters that also generate light.
We can use them as heat boosters for a room.
Electric resistant heat is not the most efficient form of heating, as we generate electricity from the primary fuel and then heat from the electricity. It's more efficient to use the primary fuel directly for heating. But the added bonus of usable light probably balances this out.
Lightbulb heating has the added benefit that typically we only turn them on when we are in the room. So it's like a resistant heater that we always turn off when we leave the room.
It can be done much more, to re direction heat to the flor.
FYI- A 60 watt incandescent bulb waste/heats (depending on this article) 54% heat with only 6% emitting light. So I guess the theory might be true?