[173889] in North American Network Operators' Group
Re: AM dust filters
daemon@ATHENA.MIT.EDU (Jason Lixfeld)
Tue Aug 12 15:44:13 2014
X-Original-To: nanog@nanog.org
From: Jason Lixfeld <jason@lixfeld.ca>
In-Reply-To: <CAEZ7Lt13tKuEgrxWGG07C1TKPUwDbZZXQhXzEQhRH=8_NDwzZA@mail.gmail.com>
Date: Tue, 12 Aug 2014 15:44:02 -0400
To: Tom Morris <blueneon@gmail.com>
Cc: NANOG <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
On Aug 12, 2014, at 3:09 PM, Tom Morris <blueneon@gmail.com> wrote:
> One important question: how often is the equipment accessed for =
maintenance?
Who knows :) Maybe it becomes someone's full time job to go do regular =
checks and maintenances of every POP? Maybe after an appropriate filter =
is found, a relatively low temperature threshold monitor is set up in an =
NMS. When this threshold is reached, it would probably be safe to =
assume a dirty filter (or some other condition that would require a =
visit) and someone could be dispatched to replace it.
> I've had reasonably good luck with air filter media coated with a =
tackifier, similar to the Dustlok media here =
http://www.filtersales.com/pagout.htm?id=3DPad%20Media
> It seems like what happens with it is heavier airborne fibers (lint, =
hair) get caught up in the first few fibers of the media, not =
obstructing airflow, and allow the finer dust to travel deeper into the =
media where it sticks to the tacky layer at the back. It lasts a good =
long while. It's single use though, so it has to be replenlished every =
now and then.
>=20
> Foam rubber media tends to have trouble with surface/airflow area vs =
pore size.
>=20
> The best option, though, will be to enclose the equipment in a cabinet =
that can be pressurized by one or more fan forced+filtered inlets. =
Middle Atlantic makes rack cabinets and fan panels that can be used to =
pressurize them that way. If you get a cabinet that takes a standard =
furnace filter, I've had good luck with the off the shelf 3M Filtrete =
Ultra Allergen filters, they have a TON of surface area with great fine =
dust capture and very low airflow resistance, even when you're drawing =
the air through them really way too fast. :)
Unfortunately a cabinet isn't possible due to a variety of issues.
>=20
> On Tue, Aug 12, 2014 at 2:19 PM, Jason Lixfeld <jason@lixfeld.ca> =
wrote:
> Hi,
>=20
> I'm interested in knowing what sorts of material folks use to make =
after-market dust filters for their various devices which wouldn't =
normally have any. This seems to almost be a necessity when these kinds =
of devices are deployed in environments that are overly dusty and dirty =
(it should also be implied that these environments are all in-doors and =
would have less than ideal airflow and climate control).
>=20
> A material that is too dense will hider airflow and cause an immediate =
increase in inlet temperature, which would exacerbate a potentially =
threatening temperature situation in environments where the ambient =
temperature is already in the mid to high twenties and above (that's 77 =
- 86F+ for my American friends ;)). A material that is not dense enough =
won't do a very good job at filtering.
>=20
> Do folks just hack up HEPA filters or something?
>=20
>=20
>=20
> --=20
> --
> Tom Morris, KG4CYX
> Mad Scientist and Operations Manager, WDNA-FM 88.9 Miami - Serious =
Jazz!
> 786-228-7087
> 151.820 Megacycles
