Forcing user to leave space for ventilation

[wwenze]

Looking through the manual of an amplifier, page 3, after 22 safety instruction pointers, there are some notes regarding placement for proper ventilation, in the same small text as the rest of the page, without bold, without capital letters, without highlight without any warning logo.

I consider these values as "for reference only", but it would be pretty sane to follow the manufacturer's recommendation of leaving 50cm of space above a class-AB amplifier rated @ 150W power consumption with a large part of the top vented.

But, I've seen a few photos of such amplifiers being suffocated by a disc player or something as big as the amp itself resting on top of the amp.

If you were a designer (or for some of you, as one), what would you do to make your product foolproof, cooling-wise?

[kevinkr]

Ideally I'd probably use a variable speed fan cooling system carefully designed so as to prevent the user from blocking the air intake and exhaust areas.

Otherwise I would design based on the premise that the end user probably will not provide adequate ventilation whatever design approach I were to take. Thermal sensing in the chassis, heat sinks, and power transformers with a front panel indication of an over temperature condition would be a reasonable approach.

No one will allow 50cm of clearance for cooling, and that goes even for guys like me who ought to know better. I would design for no less than 10cm realistically speaking.

[DF96]

Use the back rather than the top for cooling. Test it with a blanket on top. Alternatively, make the top something other than a flat horizontal surface so you can't put anything there.