Re: Experiences with rack mounted kit mounted *vertically*

On 2/5/2025 7:39 AM, Martin Brown wrote:

On 05/02/2025 12:28, Don Y wrote:

Anyone have any long-term experiences regarding (wall) mounting
rack mountable kit front-down or front-up?  Reliability,
accessibility, etc.  And, any suggestions to protect the
openings-susceptible-to-gravitational-interference?

 If it is all on forced ventilation then the only problem might be that some fan bearings are only designed to be in one orientation.

Hmmm... hadn't thought of that.  OTOH, unless the kit vendor has
noted this in his selection of fans, there's not much I can do to
determine if it would be at risk (other than wait for it to shit the bed)

Passive heatsinks won't work as well if their fins are not aligned with the direction that warm air wants to rise.

*These* switches are actively cooled so I am assuming the orientation
of fins is to ensure their exposure to the air flow.
They are switches so I imagine, internally, they are N copies of
the same basic circuitry laid out side-by-side and not a hodge-podge
of "stuff" scattered about.

Any suggestions as to which (-up or -down) might be better?

 I prefer not to have to crawl under things to see the front panel YMMV.

I'm mounting this high so I'll be looking *up* at it.  I suspect
ports down is best for long-term deployment (dust and debris less
likely to collect in an UNCOVERED port -- expecting someone to
remember to RE-cover a port made free is probably wishful thinking).
This also allows the airflow to progress from bottom to top as
the rear-mounted fans exhaust air.

My pet hate are the input connectors on big display screens in positions where it is just about impossible to reach them to plug in a cable.

Not just screens.  None of the backsides (or undersides) of the kit
in my office are easily accessible.  I've made (lamintated!) photos
of the backs of each device so I "know" the positions and orientations
of all of the connectors without having to see them.
I've also reconsidered the connectors that I will be using on *my*
kit with an eye towards durability and ease of mating (try mating
an 8P8C "blind")
Some years ago, I rescued a short (4 inch?) USB A-A M-F cable.
I couldn't imagine ANY use for it but it was "unique" enough to
merit a spot in a box of USB cables.
It has now found a home on SWMBO's laptop so she can more easily
locate the connector for her thumb drives!

For a start, I'd like to mount six 48/52-port switches.
Most of the mounting kits suggest this is within their
typical weight limits.  But, 4U seems to be the most common
arrangement (I'd like to have to avoid using two kits)

 Provided they don't run too hot should be OK.

That will be something to determine empirically.  It is NOT in "living
space" so likely to see greater temperature extremes.  But, I don't
want to bring those BTUs into the house (they are PoE ports so it's
not just the power associated with the switching fabric; ~300 PoE
ports represent a pretty substantial power load).
I figure this is the sort of engineering decision that will have to be
made in a site-specific context.