James77
Team RC
<a href=showthread.php?s=&postid=14938137#post14938137 target=_blank>Originally posted</a> by redfishsc
To a degree I think you have a point on the heat, but heat output is not a direct product of wattage used.
The issue here is "how much electrical energy are we able to convert into light-emitting energy, and how much into heat".
Think of a 1,000 watt oven burner (which is about right for a medium burner) and a 1,000 watt MH. The MH puts out a ton more light and less heat (although you could probably cook a roast under a 1,000W MH).
A 42 watt LED setup that is being sold right now is compared to a 175 watt MH in light output (which, so far as I know, hasn't been proven except by the SPS that's grown under it)---- and it's cool enough to touch with the hand.
When that created light strikes another surface- rock, sand, the walls, etc- it will heat them. The energy from the light does not just disappear- although some will be absorbed/stored by the corals.
If 250 watts is reaching a plasma bulb, and 250 watts is reaching a metal halide bulb, there will be 250 watts of heat produced. You may get far more usable light out of one of them, but it will all eventually go back to heat. Not all the heat will be absorbed by the tank- some will go into to the room, out windows- but watts are watts.
You may need less watts to get your desired light output, as in your LED example, but watt for watt the heat is the same.
