Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!lll-tis!ames!eos!aurora!labrea!decwrl!decvax!mandrill!neoucom!wtm
From: wtm@neoucom.UUCP (Bill Mayhew)
Newsgroups: comp.sys.att
Subject: Re: Fan reversal on 3b1/7300
Message-ID: <1016@neoucom.UUCP>
Date: 19 Feb 88 13:46:57 GMT
References: <409@flatline.UUCP>
Organization: Northeastern Ohio Universities College of Medicine
Lines: 15
Keywords: I've got this idea... (again..)
Summary: reversing the fan


The air flow of the 3b1's fan can be easily reversed by simply
turning the fan end-over-end in its holder.  There are a couple of
disadvantages to using positive pressure cooling though.  Namely,
all the air is first blown across the power supply, thus sending a
wave of heated air over the rest of the components.  Positive
pressure tends to have less even air flow inside the machine, thus
causing hot spots.  Adding a second fan per the original AT&T
specifications when reversing the air flow direction would probably
be a good idea.

I think I'd stick with the original cooling scheme and just make a
point of it to vacuum the inscence and stir-fried-animal-part dust
out of the machine every six months or so.

--Bill