Byte_hoven
New member
Someone has a Denon S770H in a cabinet with plenty of room either side but only about an inch to an inch and a half of clearance above, and wants to stick two USB fans on the sides, powered from the receiver's own USB port, to pull the hot air out. Sketched it with arrows and everything. The instinct is right, the placement is not.
An AV receiver dumps almost all of its heat straight up through the top grille. That is the whole cooling design, passive convection through the vents above the amp section. The sides of the chassis are solid metal, so fans blowing across them are moving air past a heatsink that is not there. Free space either side does nothing for you if the one gap that matters is the inch above. What actually helps is moving air along the top surface and out of the cabinet, so a fan sitting above the receiver blowing outward, or a rear exhaust fan pulling the whole cabinet's air out, not fans hugging the case.
The USB port is the other half of the question. That socket is there to read a flash drive. Two fans may spin slowly, may not start reliably, or may just make the receiver unhappy. The upside of using it is that the fans follow the receiver's power state, which is genuinely convenient. There are AV cabinet fan kits that do the same thing off their own supply with a thermal probe, and they are not expensive.
Has anyone actually run fans off a receiver's own USB long-term without the port giving up?
An AV receiver dumps almost all of its heat straight up through the top grille. That is the whole cooling design, passive convection through the vents above the amp section. The sides of the chassis are solid metal, so fans blowing across them are moving air past a heatsink that is not there. Free space either side does nothing for you if the one gap that matters is the inch above. What actually helps is moving air along the top surface and out of the cabinet, so a fan sitting above the receiver blowing outward, or a rear exhaust fan pulling the whole cabinet's air out, not fans hugging the case.
The USB port is the other half of the question. That socket is there to read a flash drive. Two fans may spin slowly, may not start reliably, or may just make the receiver unhappy. The upside of using it is that the fans follow the receiver's power state, which is genuinely convenient. There are AV cabinet fan kits that do the same thing off their own supply with a thermal probe, and they are not expensive.
Has anyone actually run fans off a receiver's own USB long-term without the port giving up?
