Graphics card heating during normal use-which card heats my house the least

[JTWrenn]

So I am looking at the gtx 1080/1070 specs and trying to figure the difference in heating of my room vs a gtx 970. I was thinking wattage may be the best use, but started thinking efficiency would screw up my numbers a lot since heat is an accidental by product...ie not what the wattage should be doing. So...I am at a bit of a loss. Can't seem to find any numbers on how hot does it make a room x sqft in an hour so just grasping at straws now. Any thoughts would be much appreciated.

 

[CountMike]

Open a window !!!
But seriously folks, Find component's TDP in Watts, that would be equivalent of a space heater of same wattage. With most GPUs that would be like one or two light bulbs.