Electric Heater using Light Bulbs as Heat Source-French Patent

[SkyWatcher123]

Hi all, I had built a heater previously and then stumbled onto this patent.
https://patents.google.com/patent/FR2504768A2/en?oq=FR2504768A2
My previous heater was using forced air from the bottom and then had plates inside to snake the air flow path around the bulbs.
It is now modified as a convection heater, with a bottom port and a large opening at the top, using 4 - 100 watt incandescent bulbs from the dollar tree.2 sets in series and then placed in parallel, to achieve the half voltage, under driven as shown in patent.
Also, the bulbs are wrapped in aluminum foil.The patent claims the heater is able to use 4 times less power for the same result as a typical space heater.
So far, the bulbs seem to be holding up fine, as long as enough convective air flow is allowed for, since I'm not using fans in my design.
Each 100 watt bulb in each series pair is using around 31 watts, though the patent suggests using a much larger number of lower wattage bulbs, probably for longevity or their is an added efficiency benefit also.
So at the moment, the heater is using around 125 watts input and the temperature at the top opening is 105 degrees F.
It is raising the temperature in this 250 sq,ft. room by 2 degrees F., (with outiside temp of 35 F.), which has much loss, 3 skylights, 1 door with large window and 2 windows.
Seems like the claims may be close to the truth.
I plan to expand the heater to at least 375 watts, using 3 separated compartments.
Your thoughts and comments are appreciated.
peace love light
(https://i.postimg.cc/c69CT471/french-heater-patent-a.jpg)
(https://i.postimg.cc/FYcK9yM1/french-heater-patent-b.jpg)

[memoryman]

It's nonsense.
Resistance heaters are 99.9% efficient. At half voltage, incandescent lightbulbs are just heaters.

[antijon]

Memoryman, true all electric heaters are nearly 100%, but the efficiency of transferring heat to air will vary by heater. I'm wondering if the greater surface area of dozens of bulbs may be more efficient than a coiled heater wire, maybe because air has such a low thermal conductivity.

[SkyWatcher123]

Hi antijon, that's exactly what I was thinking, the patent uses 75 - 15 watt bulbs at half voltage.
Thermal transfer is probably the key here.
The only thing is, I'm not sure what physical size bulbs he was using, though it says they are globe type.

Will look into it further if i can, if not, i will just keep experimenting with this idea.
Also, the wrapping of the bulbs in aluminum foil boosts the temperature of each bulb, beyond the normal temp. they would generate, maybe that helps heat per watt as well.Also, that aluminum foil will create a better thermal transfer to air as well I would think.

As i researched on my previous heater project, I found that typical steam radiators, without the proper physical size of radiator, it will not even heat a closet properly.
So thermal transfer is a huge consideration, maybe one that is being overlooked and this patent is pointing it out to us.
peace love light

[lancaIV]

Hello skywatcher,using IR-waves emitting heatwaves bulbs I would recommend the ceramic bulbs used for chicken or snakes grow.About the french 75x times bulb array  publication I would say: internal resistance.Probably for a search trial about VoltAmpere in and heat in kcal/KJoule out :Dragan Kovac - WO200410034911 series connection of single resistors -- connection like a dimmer ?
......
Look for this publicated "utility model US201301125" presented by Charles Edmund Souders.Here the question: how many sqfts has in average an american household(insulation condition) and climate zone,cause he describes an "only 600 Watts" need for the total space !With his address in the original document and white pages online phone number search he probably will give the correct information.
Sincerely           
              OCWL
p.s.: Pavel Imris "Optical Electrostatic Generator" of series connection elements using as heater ?Like : WO9628954 Heat Generation Device
Incandescant bulbs, fluorescant lamps, graphite felt elements : there is no restriction to use these not as heater