Clue: Energy unit – do not feature in air-cooled device (7)
Answer: CALORIE
Explanation: Energy unit – do not feature in air-cooled device (7) 
*(air cooled – do)
 
This doesn't work for me grammatically – the voice of "do not feature" is wrong. The setter has seen a clever device, but hasn't been able to make it work properly, in my opinion.