I have a client who fitting a Microbus with a small PV system and a 12/3000 Multiplus II. Considering the very limited space, the location he plans to mount his horizontally. Looking at the chassis of the inverter, it is clear that it was designed for flow through bottom vents and out the top. The manual does not say specifically the unit must be mounted vertically. He has taken every precaution and has large bottom and top holes in his cabinet for air flow through the area. Horizontal is not ideal but from a warranty perspective is this unit at risk?