Richard Clark wrote:
"Actually that is quite wrong. IR is not heat."

He got me. According to Lincoln`s Industrial Reference, from a 100-watt
MAZDA lamp the amount of energy emanating as light is 10%, and as
infrared is 72%. The rest is lost to gas end loss, etc. The loss would
be only 18% You can`t see infrared. The eye is most sensitive to a
yellow-green color around 5550 Angstrom units. Lamps are made to
emphasize white or "daylight" which is rated at about 2400 to 3100
degrees Kelvin.

Best regards, Richard Harrison, KB5WZI