We all know someone who's obsessed with energy efficiency, regardless of whether they can afford a high electric bill or not... You know the type: the ones who go ballistic if you leave the light on, even if it's a ten watt LED, and plug every single new appliances into a multi-meter the second it comes in the door. Maybe you live with that person. Maybe you ARE that person.

So here's a question for the wattage nuts out there: all else being equal, and assuming normal, safe operation of all devices, what's the most efficient heat source, in terms of how much it raises the temperature in an enclosure vs how many watts it consumes? I suppose that may be a two part question, if you consider heat sources meant to just provide a basking spot separately from heat sources meant to raise the ambient temperature.

In other words, if an 80 watt rhp heats the enclosure as much as a 100 watt bulb, it's more efficient. Obviously, insulation and the type of enclosure matter too, but that's sort of a separate question (unless you can think of a situation where product a is better at heating one kind of enclosure and product b is better at heating another).

Put it this way: I have a couple of friends who like to compete to see who can get their utility bills the lowest. They are engineers who enjoy optimizing systems, diy home improvement, etc. The guy who usually wins managed at one point to use so little water that he got a letter from the city asking that he notify them if the property was unoccupied. If that guy were shopping for reptile equipment, what would he buy? (Actually, that particular guy would build his own from the immaculately organized spare parts in his garage, but you get the idea)