The KWH to Heat of incandescent lamps is 95%-99.9% efficient. (If you do not let the light out of the room, all the heat and essentially all the light ends up as heat.)
> lamps are most often on the roof (ceiling?) and since heat goes up, it's will find its way out of the building before it'll do any good.
That is a point.
When I stand under a 200W lamp in reflector, I sure feel heat, and similar to 1/6th of a 1,200 watt radiant heater.
> non-electric central house heating aided with incandescent bulbs and apparently this is a terrible idea in terms of efficiency and cost.
Right. Wood or oil or gas is many times as much heat for a buck. A dollar burned in electric light is $0.30 saved in heating fuel. Or, as you say, less if the lamp heat rises away from you and out of the house.
If you do heat with electricity, and pay the same KWH rate, then lamps are not the worst deal. Again they tend to be placed for best light, not best heat. Perhaps half the heat escapes without touching you, though even this will warm the surfaces.
If you aim the heat where you want it, a lamp is as good as any other electric heater. And if you only want a small warm spot in a large house, lamp is more efficient than running the centeral electric heat. Even if you shut-down registers in other rooms, there's a lot of stray heat in a large central heating system.
Some very large buildings (low surface/volume ratio) with incandescent and even fluorescent lighting, will stay warm with almost no suplemental heat. Very large office buildings often simply move the air from the core out to the perimeter. Of course this is partly lighting heat and partly the BTUs coming off the workers. (and now non-negligible heat from PCs and printers.)
I think what the experts are saying is: in home-size buildings, with home-size lighting patterns (not 30fc 8am-9pm like an office), the amount of heat from lamps is so small that it makes no difference which size main heater you will need, and burning electricity when wood/oil/gas is available is a bad deal.
> fridge heat-waste can be used to increase overall house heat
And hot-water storage. We have a demand heater in unheated cellar. It might be poor choice to put a storage heater down there, it would work too hard to stay warm. We were thinking to put one upstairs in the warm house, but didn't.
> I have 3x 60w bulbs mounted under my computer desk, only inches away from legs and they are very effective leg/feet warmers.
I would kick the glass bulbs then step in the shards.
Also doesn't the light annoy?
I use a Sengoku mini-panel SP-160. 150 Watts in enough surface that it doesn't run real hot, but really warms the cubby under the desk. I let the air in the living room get quite cold, because I'm fine with warm feet and the curtain of lukewarm air over lap and face. While elecric is 3X-4X the cost/BTU of oil, I'm heating 3'x3' instead of 24'x30'.
