Glass or Metal?

[GreekMan]

Which would transfer heat to water more efficiently, a glass beaker or an aluminium can?

[insane_alien]

aluminium can, glass has a very low heat conductivity and aluminium has a very high heat conductivity. infact aluminium has such a good conductivity that it is used in heatsinks for cpu's and other electronic devices. copper is better and is used in industrial and high end heat sinks then silver which is the best(IIRC) which is rarely used in heatsinks due to the high cost.

 

glass on the other hand is a poor conductor of heat, it is actually an insulator.

[YT2095]

the Alu can, without a doubt.

 

IIRC the absolute Best would actualy be Silver (Ag), in both Thremal and electrical conductivity (they also generaly tend to share this trait, that if they conduct electricity well, the same will apply to heat).

[encipher]

I thought gold was? I know they use it in real expensive cars and audio equiptment because its pretty much the best ?

[YT2095]

actualy gold comes a little furter down the list, and more often that not its actualy Paladium that used instead.

Gold has better anti oxidising characteristics, that`s all, and paladium Looks like gold and works just as well and can demand Gold Type prices from the market that thinks all this stuff makes a Difference.

[insane_alien]

gold is used because its good at shielding from electromagnetic noise from other electronic gadgets like hoovers, and electric motors (and the coils in combustion engines). there are better things than gold for heat conduction and electrical conduction.

[YT2095]

gold is used because its good at shielding from electromagnetic noise from other electronic gadgets like hoovers, and electric motors (and the coils in combustion engines).

 

you ARE kiding right?

[insane_alien]

am i? i heard gold was good at shielding signals from external electromagnetic interference. but this is off topic and nothing to do with heat transfer.

[YT2095]

no, it`s nothing to do with shielding, that`s just a marketing idea that folks buy into (literaly), Gold is used in Contacts as a way of ensurin a good connection that won`t oxidise easily over time, that`s all. and I I said that which may LOOK like Gold on earphone jacks etc... is actualy Paladium metal.

 

in Order it`s: Silver(Ag), Copper(cu), Gold(Au), Aluminium(Al).

 

and glass isn`t all THAT "Bad" of a heat conductor either, it`s a perfectly Ionic bond and will conduct electricity excellently when molten also

[swansont]

Having recently dealt with the issue, I can tell you that if you want to shield against 50-60 Hz, foil isn't going to do it. The skin depth (1/e attenuation) for copper is 8.5 mm at 60 Hz. Gold and silver would likely be similar.

 

(some contractors at work wanted to put 480V 225A power lines right next to our data conduits, and assured us that the concrete encasement would shield them. Concrete is not as good as copper by a large margin)

[YT2095]

wouldn`t a soft iron condiut have been better?

that can be made as a "baffle" like in a muffler/exhaust pipe and totaly loose the 60hz to heat energy entirely!

[swansont]

wouldn`t a soft iron condiut have been better?

that can be made as a "baffle" like in a muffler/exhaust pipe and totaly loose the 60hz to heat energy entirely!

 

Yes, because it has a high permeability. But the construction specs called for concrete, though they were free to pack it with rebar. They also called for ~5m separation from the data conduits, so we had them move the power line further away.

[YT2095]

well reinforcement bar/mesh won`t be a whole hell of alot of good unless they hope for some sort of mega slack-a$$ farraday cage affair!

 

Oh Dear ))

[Prime-Evil]

Which would transfer heat to water more efficiently, a glass beaker or an aluminium can?

Perhaps this was a trick question. Under certain conditions, like direct sunlight, the glass beaker will allow more heat to be transfered by radiation. In the case of a bunsen burner my money would be on the aluminum can, but under certain conditions, like if the flame was on the side instead of underneath, the glass beaker might win again. Depends on a lot of factors, including the temperature of the water, and the temperature and pressure of the air, assuming there is air.

[Primarygun]

I can't believe that diamond can transfer heat much faster than others, though I know it is a good heat conductor.

and at temperature, gold is a little bit better than aluminium

[jdurg]

Actually YT, palladium looks NOTHING like gold. Palladium is a bright, silvery metal while gold is a nice yellow (golden) color. Palladium is often used in the place of silver because it looks a lot like silver but won't corrode like Ag does.

[Gilded]

I happen to own some pure palladium and it indeed is quite silvery and white so I can account for that also. I'd imagine some palladium alloys could look pretty much like gold though.

[GutZ]

What about platinum? err I think that electrical conductivity.