Acrylic Case Thermal Performance

Are there any weird thermal issues that come with a completely acrylic
case (all material is transparent)? One kid at school said cases are
aluminum for heat dissipation, but I think he was a little loony.

I suppose if I sat it in direct sunlight it would be like a
greenhouse. Things might not be so pretty after the case temperature
goes over 100 degrees.

Seriously though, do you guys know of any other issues heat issues?
I've also heard some people rattling on about electromagnetic
interference (EMI). Is there anything to that? I've read reviews,
and nobody has complained of things going wrong.

Case arrives on Monday, can't wait!!!

Aaron

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Aaron wrote:

> Are there any weird thermal issues that come with a completely acrylic
> case (all material is transparent)? One kid at school said cases are
> aluminum for heat dissipation, but I think he was a little loony.

Unless you have a reason to use the case as a heatsink (such as bolting
semiconductor rectifiers, voltage regulators, or power amplifiers to it),
the material from which the case is made should not affect the computer.

>
> I suppose if I sat it in direct sunlight it would be like a
> greenhouse. Things might not be so pretty after the case temperature
> goes over 100 degrees.
>
> Seriously though, do you guys know of any other issues heat issues?
> I've also heard some people rattling on about electromagnetic
> interference (EMI). Is there anything to that? I've read reviews,
> and nobody has complained of things going wrong.

The RFI (Radio Frequency Interference or electromagnetic interference) may
be an issue.

Computers in general are considered in two classes: A and B.
Class 'A' computing devices are intended to be used within a commercial
environment, and a Class 'B' device is intended for the residential or
consumer market.

The excerpt below is from the FCC Rules, Part 15 which cover unlicensed
radiators and interference issues:

// begin excerpt

(h) Class A digital device. A digital device that is marketed for use in a
commercial, industrial or business environment, exclusive of a device which
is marketed for use by the general public or is intended to be used in the
home.

(i) Class B digital device. A digital device that is marketed for use in a
residential environment notwithstanding use in commercial, business and
industrial environments. Examples of such devices include, but are not
limited to, personal computers, calculators, and similar electronic devices
that are marketed for use by the general public. Note: The responsible
party may also qualify a device intended to be marketed in a commercial,
business or industrial environment as a Class B device, and in fact is
encouraged to do so, provided the device complies with the technical
specifications for a Class B digital device. In the event that a particular
type of device has been found to repeatedly cause harmful interference to
radio communications, the Commission may classify such a digital device as
a Class B digital device, regardless of its intended use.

// end excerpt

If you purchase a 'blade' server from HP for example, it will likely be
classed as 'A' while a Compaq Desktop machine (again, as an example) from a
retailer will probably be in the 'B' class.

*Building* the machine from parts purchased not as part of an integrated
whole sticks it in the 'B' class, from everything I've read.

A well-manufactured metal case and high-quality assembly by the assembler
(you, your sister, anyone else you choose to perform the task) will help to
reduce any electronic emissions from the computer.

You might see such interference on a nearby television, hear it on an AM or
general-coverage short-wave receiver, (or not ever notice it until the
Vogons home in on it and target your neighborhood).

It is highly unlikely, though, that emissions from your new system will have
any effect on most devices within a short distance of your computer.

An acrylic case will not offer the shielding of a metal case (obviously),
but it will certainly be neat to look at !

> Case arrives on Monday, can't wait!!!

Go for it!!

>
> Aaron

- --
Ron n1zhi

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Ron Cook <> wrote in message news:<4pr4p1->...
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Aaron wrote:
>
> > Are there any weird thermal issues that come with a completely acrylic
> > case (all material is transparent)? One kid at school said cases are
> > aluminum for heat dissipation, but I think he was a little loony.
>
> Unless you have a reason to use the case as a heatsink (such as bolting
> semiconductor rectifiers, voltage regulators, or power amplifiers to it),
> the material from which the case is made should not affect the computer.

In my experience of building computers, the case material does
influence the internal temperature of a case, however not to the
extent that manufactures would like you to believe. There is more
important things you can do to ensure a cool operating temperature,
for example having sufficient fans in the case, having balanced CFM
for intake and exhaust fans, making sure you have good air flow front
to back in the case, making sure to clean the case out from time to
time depending on how dusty your environment is, etc

Good luck with the case

(jamotto) wrote in message news:<. com>...
> In my experience of building computers, the case material does
> influence the internal temperature of a case, however not to the
> extent that manufactures would like you to believe.

Correct. Air does not transfer heat efficiently from the hot parts
(your power supply, processor, add on graphics card, and drives) to
the case. As noted below, good airflow through the case is a bigger
factor.

Think of it this way: If I pumped a couple of cubic feet of 200
degree air into an airtight aluminum case, I could check back in a
couple of hours and find probably 190 degree air inside the case.

If I put the same hot air into a case with vents at the top and
bottom, the air inside the case will be room temperature in a minute.

> Good luck with the case

Ditto, and I agree with Ron: go for it!

(Aaron) wrote in message news:<. com>...
> Are there any weird thermal issues that come with a completely acrylic
> case (all material is transparent)? One kid at school said cases are
> aluminum for heat dissipation, but I think he was a little loony.
>
> I suppose if I sat it in direct sunlight it would be like a
> greenhouse. Things might not be so pretty after the case temperature
> goes over 100 degrees.
>
> Seriously though, do you guys know of any other issues heat issues?
> I've also heard some people rattling on about electromagnetic
> interference (EMI). Is there anything to that? I've read reviews,
> and nobody has complained of things going wrong.
>
> Case arrives on Monday, can't wait!!!
>
> Aaron

Hi Aaron, All the PLASTIC cases I have seen have RF shields in the
form of metal sheets attached inside the panels and places for two
more exhaust fans. Jim

(Aaron) wrote in message news:<. com>...

> I've also heard some people rattling on about electromagnetic
> interference (EMI). Is there anything to that? I've read reviews,
> and nobody has complained of things going wrong.
>

I'll add my experience, but always take it with a grain of salt. I
recently converted a laptop from a regular laptop IDE to a standard
40-pin IDE (long story). The 40-pin IDE cable traveled unshielded
outside to a hard drive about 6 inches away. Every time the laptop
accessed the hard drive, I could easily detect the EMI on a TV 10 feet
away. More importantly, the data transfers between the laptop and the
hard drive had errors from the outside EMI to the cable. This
eventually corrupted the data on the hard drive and it had to be
reformatted. (Took me a while to figure out why the data kept going
bad - and a real pain if you're trying to install an OS). What I
ended up doing was take some aluminum foil, and wrapping it around the
IDE cable. This reduced the EMI output dramatically and the
laptop/hard drive now works fine. Just a thought in case you find you
have a lot of stability problems and don't know why.

By the way, in case you're wondering, laptop cases are plastic, but
are also conductive in order to reduce EMI.

> Case arrives on Monday, can't wait!!!

You probably won't run into a problem. Good luck!

>
> Aaron

(Jason) wrote in message news:<. com>...
> (Aaron) wrote in message news:<. com>...
>
> > I've also heard some people rattling on about electromagnetic
> > interference (EMI). Is there anything to that? I've read reviews,
> > and nobody has complained of things going wrong.
> >
>
> I'll add my experience, but always take it with a grain of salt. I
> recently converted a laptop from a regular laptop IDE to a standard
> 40-pin IDE (long story). The 40-pin IDE cable traveled unshielded
> outside to a hard drive about 6 inches away. Every time the laptop
> accessed the hard drive, I could easily detect the EMI on a TV 10 feet
> away. More importantly, the data transfers between the laptop and the
> hard drive had errors from the outside EMI to the cable. This
> eventually corrupted the data on the hard drive and it had to be
> reformatted. (Took me a while to figure out why the data kept going
> bad - and a real pain if you're trying to install an OS). What I
> ended up doing was take some aluminum foil, and wrapping it around the
> IDE cable. This reduced the EMI output dramatically and the
> laptop/hard drive now works fine. Just a thought in case you find you
> have a lot of stability problems and don't know why.
>
> By the way, in case you're wondering, laptop cases are plastic, but
> are also conductive in order to reduce EMI.
>
> > Case arrives on Monday, can't wait!!!
>
> You probably won't run into a problem. Good luck!
>
> >
> > Aaron

Well, I got it, and it works fine. I had never guessed moving
everything would take so long, though (three hours). I can't detect
any problems.

Thanks for the input.

Aaron