I have been using my 2 x v3 mono for several months now in a niche above the musicla fidelity cd player which also works as a great heat sink and I must say that despite continuous use I have never had any heat problems. I had thought of inserting a fan on the side given the limited space but everything works perfectly and the heat developed is never excessive. A sign of good construction engineering and perhaps the passive dispersion despite the limited space works really well