not sure what you mean , you seem to be confusing heat and power
heat is generated because of resistance (R)
overall heat from an electrical device is also dependent on what the device is
1000w of power consumed by any type of light is not 1000w of heat
heat is not part of ohms law it is a byproduct of (R)
a MH produces a huge amount of heat because of the way MH generates light
the center of the bulb is very hot
sodium produces less heat because the center of the sodium tube is not as hot as the MH
this example should clarify beyond doubt
does a 3kw (3000watt electric fire
produce the same amount of heat as a
3kw (3000w) air conditioner
they both consume the same amount of power
you seem to be suggesting they would produce the same overall amount of heat since they are both 3kw
put a 3kw fire in a room a 3kw air conditonr in another room, both rooms will be the same temp ?