heat creation of typical heat block

Does anyone know or have a link to what the heat output is for the typical heat block with a 12v 40 watt cartridge heater is in watts or BTU/hr? I tried the math myself, just a little above my skills. Or if someone can help explain the math- that would be even better, teach a man to fish...

I've estimated it at @800 BTU, but I'm not sure if that is even close.

In the end, what I am looking for is the amount of cooling (or heat extraction) is needed above the heat break.

Thanks

A 40-watt heater puts out 40 watts of heat. All heaters are perfectly efficient, unless they have a super-powerful light or something built in. Do keep in mind, though, that you're gonna lose a lot of heat through the heat block, heatsink or no.

Thanks- I did not realize heat watts and power watts are the same. I was over thinking things, I guess.