Shiny Side Down!

[erufiku]

thanks for the shiny side up tip for tangiers. smokes better (in my experience).

[NickReppinThe909]

i use shiny shide up except when im smoking AF or layalina because IMO they are higher heat tobaccos but shiny side up makes heat management slightly easier

[manic007]

This is an interesting debate. I dont want to brag or anything, but I havee a degree in physic so maybe I should give my 2 cents. But I'm going to be uber lazy and not both giving reference to anything that I say, so you'll either have to google it, or look it up in a physics text book. And finally, its physics, so yes you might find it boring.


First of all, basic physics, anything that has a temperature above "absolute zero" (-273 degrees Celcius) will emit photons. The colder stuff is, the more longer wavelength photons it emits. Also the opposite is true, as the thing gets hotter is starts to emit short wavelength photons. Stuff that is at room temperature emits infra-red photons. Are you guys getting bored already?!! Stay awake! This well known phenomena is called "blackbody radiation" (google it something).

The shisha is hot because of the hot air that passes through it. Assuming the shisha is at a temperature of 300 degrees Celcius, then it emits most of its blackbody photons at a wavelength of 5 micons. If you wonder how I did the calculation so quickly in my head, I used this:

http://hyperphysics.phy-astr.gsu.edu/Hbase...evbm=&evpm=

So question 1)

Does Aluminium reflect infra-red photons of wavelength ~5um? Or, does it absorb it!

Answer:

It generally reflect 5um light, I know this I've worked with that wavelength Here's a well known company that makes optics for research (Newport) they sell Aluminium mirrors. Ignore the "enhanced" bit, I'm sure thats just a protective coating to stop it oxidising due to the air, important bit is the graph near the bottom:

http://www.newport.com/store/genproduct.as...mp;Section=Spec

so this leads to the second question

question 2)

Does a shiny surface reflect more light than a dull surface

Answer:

In theory no. In practice, probably marginally more.

In theory, its simple. Energy is neither created or destroyed. So when the photons from the shisha hit the foil they are either reflected or absorbed. The question can be refined to, does a shiny surface absorb less light than a rough one. Heres a more elegant answer than I can put:

http://atomic-molecular-optical-physics.su...light_in_optics

Intuitively, you can think of a shiny surface like one large mirror. While a dull surface as lots of microscopic mirrors all orientated at funny angle. Because of the different angles light will be reflected at all sorts of angles, so its a much more complicated system. But in theory no more light is being reflected by the large mirror, than the many microscope mirrors. The many mirrors are just spreading it everywhere.

So why are those space-age Al blankets shiny? Its probably because they're manufactured to be a certain thickness, for reasons of flexibility. And they come off some sort of roller. Basically, coincidence. If you "scuff them up" then you shouldn't see any drop in heat reflecting efficiency. Note: not all metals reflect in the infrared, some absorb!

However ancedotal evidence (and complicated reasons) has lead me to believe that shiny surfaces reflects TINY amount more light than heavily scratched/pitted surfaced. But generally JillyIsJustKidding is right, it makes little practical difference.

HOWEVER! If Alademuerte is right, then its likely that whatever coating they use on the dull side of Aluminium cooking foil will dramatically decrease the reflection efficiency.

So there you have it. Aluminium foil reflects the heat from shisha fairly well. In theory a dull surface reflects the same amount of light as a shiny surface (just that one is diffuse reflection while other is specular). But in practice if the manufacturers do put a coating on the dull side then is highly likely that will drastically reduce its efficiency

Bored?? Well, welcome to my world.

[r1v3th3ad]

I didn't think there was a difference in either side, but I thought " Alas, its shiny which means it has to reflect more, equaling more heat..." so, I generally put it sunny side up so that the coals burn hotter...don't wanna burn my sheesh

[teq]

@manic:

I wouldn't have trouble agreeing with you, except for the fact that your comparison of the shiny and dull sides is based on two seperate pieces of aluminum.

With one piece of aluminum, the variance between the shiny and dull side marginalizes, as most energy is absorbed and transferred via convection and conduction.

The reflectivity shouldn't affect its emissivity, but it should change the amount of infrared light absorbed from the coals.

[manic007]

@manic:

I wouldn't have trouble agreeing with you, except for the fact that your comparison of the shiny and dull sides is based on two seperate pieces of aluminum.

With one piece of aluminum, the variance between the shiny and dull side marginalizes, as most energy is absorbed and transferred via convection and conduction.

The reflectivity shouldn't affect its emissivity, but it should change the amount of infrared light absorbed from the coals.

Yeah its probably true in this situation more energy is transferred by convection and conduction, rather than radiation.

However if I knew what, if anything, manufactuers coated the dull side with, then it could potentially make a noticeabley small difference (if that makes sense).

[teq]

I don't think it's coated.

http://en.wikipedia.org/wiki/Aluminium_foil

[r1v3th3ad]

but thats wiki... anyone can change it, as we've seen mathuv dicking around with it before

[teq]

but thats wiki... anyone can change it, as we've seen mathuv dicking around with it before

Duly noted, but it's a good culmination of references.

[r1v3th3ad]

but thats wiki... anyone can change it, as we've seen mathuv dicking around with it before

Duly noted, but it's a good culmination of references.

agreed

[Rani]

I've always used shiny side down on tobacco that handles heat well and shiny side up on those that are more heat sensitive like Tangiers and some flavors of Fantasia. Of course it could simply be the power of my fantabulous mind but that system seems to work wonders for me. I can even break it down to a simple equasion: If it's washed it's not generally so heat sensitive in my opinion so shiny side down. Unwashed shiny side up. Simple.

'Rani

[Bawhee]

[quote name='ganesha' timestamp='1208817004' post='242534']
Being lazy I buy the sheets made for hookah... I can't tell a difference in the sides... It does make sense that the shiny side down would reflect the heat into the bowl... Maybe I'll have my daughter do her science fair project on this ... Measuring the temps using different brands of foil shiny side down verses "dull" side down...
[/quote]

ok, I know im being a total necro, but I was wondering if the matte/shiny side up actually mattered and searched, the reason for this post is just the fact that no one and I mean NO ONE noticed how funny (and fucked up in the minds of teachers and most parents that are all freaked by smoking anything) it would be if someones daughter had heat management in smoking hookah as her science fair project

[mushrat]

Having packed thousands of bowls i can say that there is no practical difference between up or down. As for thescience fair, heck that thread went cold 2 years before most current people even joined.

[angekfire]

I've always put shiny side down figuring it would help reflect the heat a bit.

[S3cretz]

Shiny side down Health reasons im serious go look up what happens when aluminium oxidizes the shiny side tends to oxidize easier.
Someone did a study ill see if i cant find it somewhere

[dizzbizz]

I put shiny side down for aesthetic reasons. I don't like my bowl to be shiny as hell

[â€On]

I put the shiny side down because I don't want my shishas thoughts escaping from the bowl. I smoke those thoughts! They add to the flavor! As an added bonus, the government cant hear what my shisha is thinking while I smoke, either. Talk about a two-fer! What a deal! I'm crazy!

Anyways, it doesn't matter, it's aesthetic. Shiny down for me.

[ezxen]

shiny side down because its what im used to

[Big Boss]

I go shiny-side-down simply out of habit. I don't believe it affects the heat either way.

[Scrappydoo]

I always do it, too! I thought it was to keep the heat on top from reflecting and diverting away the heat. Funny how the smallest things make a difference!

[Fusion]

Yes, always! I never really thought about why, but as has been mentioned, it's just more aesthetically pleasing to me.

[TheyCallMeDave]

I put shiny side which ever way it happens to be when I have it in my hands. I just wanna smoke.

[mushrat]

[quote name='aeon' timestamp='1311631594' post='517214']
I put the shiny side down because I don't want my shishas thoughts escaping from the bowl. I smoke those thoughts! They add to the flavor! As an added bonus, the government cant hear what my shisha is thinking while I smoke, either. Talk about a two-fer! What a deal! I'm crazy!

Anyways, it doesn't matter, it's aesthetic. Shiny down for me.
[/quote]

You, I Like.

[TweakX4]

i've always put shinny side down because that's what i was told to do.

but, yesterday i put shinny side up while smoking some tang and it felt wonderful to break the mold!

[Scrappydoo]

OK I did an experiment today to ease my own mind. (No work and hubby out of town makes Brenda do weird things! ) I took two peices of foil, one shiny side up and one shiny side down. THEN I put coals on it. You can feel the heat radiating off of the shiny side MUCH hotter than the matte side. I am sure it has something to do with heat maintenance.