Yes that is true, what ever energy is put in has to manifest itself somewhere else. So yes his room would be warmer with the 290s I thought he was talking about efficiency of coolers to their GPU. But even then he said he was mining on the cards to do so, if he were to mine on his 970s 24/7 the effect to his room could be the same overtime. 290s mining 24/7 100% and two 970s mining 24/7 100% if they were to both reach sustained GPU temps of 80c would have the same effect on the room, till the room reached 80c then the 290 would heat past that quicker. Interesting, more thought then I wanted to put into it.