humm...

http://ronin-kakuhito.livejournal.com/264096.html

Okay lords and ladies, I have a question. How can an electric space heater be more or less efficient? (Not a heater/blower combintation, I get how moving warm air around makes it so that you need less warm air for the same amount of comfort.)
As I understand it, electricity is charged on the watt hour or the kilowatt hour, which is really pretty much a way of saying "joule." I get charged per joule that I use, so for most devices, I pay extra money for all of their waste heat. The release of heat costs electricity, and all of the heat that is released comes out of my power bill. But with a space heater, waste heat is the mission goal. My heater sucks on the outlet, takes in x joules of electricity, which I am charged for (and I am not charged for any joules that it doesn't take in) Assuming that my heater doesn't have exposed glowing coils (which release visible light which doesn't all become heat while still in my house) shouldn't any heater be as efficient as any other heater of the same wattage?