Average temperatures in normal use: is my unit too hot? How do you ventilate it?

The problem fan is bug the firmware, in reality fan will be active at too high temperature. You can see at work through test system. I contacted support and said me temperature hot is normal. Hard disk temperature I solved improving cooling with another fan. Look at picture attached. This reduce temperature ten degree!! Ask me if you need another informations (specific fan, electric link, voltage).