Speculation about how vapour clouds form

Stu said:

I did this experiment, too. I was pretty surprised tbh that there was no browning of my load at all. I expected a little bit since there's a hot coil millimeters below the bowl. I've also done this test with the Solo and the herb came out looking totally spent. The Solo (and the Crafty and several other battery operated portables) use preheating of the bowl as it's more energy efficient than straight convection. I won't call it conduction because I don't think it is, but the preheating does roast the goodies in varying degrees depending on the model IME.

Click to expand...

Yep I remember...in fact the whole thing started with the assertion that the Solo is more conduction than convection as evidenced by its no-draw cooking of material (OK it was me who made that assertion.) One of the symptoms of conduction in my house is my wife saying "are you burning something?" as vapor seeps out of an unattended device.

I guess we are doomed to re-litigate this subject every few months in one thread or another.

For shits and giggles I sacrificed a bowl of White Fire to run the "no draw for a session" test with my Crafty as I've done with several other vapes.

(Fresh herb on the right for comparison)


As you can see the radiant heat in the chamber roasted the load pretty well during a 12-minute (drawless) session at 190°C.

IMO battery-operated portables come in 4 basic groups as it relates to how vapor is produced:

1. Oven based vapes that do not pre-heat incoming air for a convective effect (Pax, Indica, VB2.0 etc.).
2. Vapes with pre-heated chambers that utilize radiant heat to maintain a baseline temperature (below optimal vaporization temp) and introduce heated air for a convective effect (Solo, Mighty/Crafty, Inhalator etc.).
3. Vapes with no pre-heated chamber that use mostly convection for heat energy transfer creating vapor production(FireFly, Elevape SV, Thermovape T1 etc.).
4. On demand conduction vapes that have direct contact with the heating element (MFLB, FV).

They each skin the proverbial cat from a slightly different angle, and bring their own set of benefits and drawbacks. It is up to each individual user to decide what type of vape suits them best, and we are pretty damn lucky to be living in the vaporizer wild west these days when options become more plentiful each day it seems.

@Stu That was a good test but, you have to remember it isn't really roasted such as coffee, its just less chlorophyll due chlorophyllase degrading the chlorophyll. This is the main reason why looking at the color of the abv isnt a good test to see if your herb is spent, in my opinion. You can get a dark color of herb just by leaving it out in the sun but, its still will have actives left.

To really see if the herb is spent would be to put it into your vapexhale and see if any clouds come from the herb, at 190c. My theory is it would be thick clouds because chances are, leaving the herb in the chamber for 12 minutes at that temperature with no air movement, decarboxylated a lot of the cannabinoids. Some thc would have oxidized into cbn as well, giving a more "relaxed" high, but that depends on how much thc oxidized. Try it out and let us know what happens, if you want.

luchiano said:

@Stu That was a good test but, you have to remember it isn't really roasted such as coffee, its just less chlorophyll due chlorophyllase degrading the chlorophyll. This is the main reason why looking at the color of the abv isnt a good test to see if your herb is spent, in my opinion. You can get a dark color of herb just by leaving it out in the sun but, its still will have actives left.

Click to expand...

For once we are on the same page. I agree that colour change is not a function of extraction, it's caused by chlorophyll degradation.

luchiano said:

You can get a dark color of herb just by leaving it out in the sun but, its still will have actives left.

Click to expand...

But wouldn't the same heat and light that degrades the chlorophyll also degrade the THC? Leaving it is the sun will make it have less activities.

Even with no air movement, wouldn't the oils reach boiling point and evaporate off, sticking to the oven.

I would think so too, @Tweak.

Here are a couple videos showing that you can get clouds with convection with minimal effort. Both use approx. 0.05g of material or less.

Tweak said:

But wouldn't the same heat and light that degrades the chlorophyll also degrade the THC? Leaving it is the sun will make it have less activities.

Even with no air movement, wouldn't the oils reach boiling point and evaporate off, sticking to the oven.

Click to expand...

It depends on how fresh the herb is. If it is fresh herb, the acids have to first break off before the cannabinoids oxidize. If its not fresh herb, then yes.

As far as the oils reaching boiling point, and sticking to the oven, that depends on temperatures used. Stu used a low enough temperature to keep the THC intact. You have to remember with a packed chamber that has no air movement, the temperature of the actual herb will slowly raise to the temperature of the bowl, and that will take time. During that time breakdown of acids need to happen before boiling will occur. The flavor might leave though because those boil at much lower temperatures.

Ratchett said:

I'm comparing SS to other metals which are more conductive of heat - such as aluminum and copper. There's a reason why CPU heatsinks are made from Copper/Aluminum and not Stainles

Click to expand...

That is also why top quality SS cookware like All-Clad is actually a sandwich where the inner layers are aluminum for its conduction properties, and only the outside is SS for its lack of reactivity.

The Solo experiment shows what leaving the bowl in a heating/heated chamber without taking a draw will do. I like to leave the the bowl in the oven while the Solo reaches my temp and even then I wait a minute before taking a hit. BUT for those who don't want to pre-heat the bowl just wait till it hits your temp and then put the glass draw pipe in and start your session. The other day I finished off a bowl with the straight stem and had the bent one already filled so I just took out the straight stem and put the bent one in and hit right away hamster style and got a nice cloud (Level 4). I didn't expect the result I got to be so cloudy because I'm a creature of habit and have always warmed bowl before starting a session.

His_Highness said:

The Solo experiment shows what leaving the bowl in a heating/heated chamber without taking a draw will do. I like to leave the the bowl in the oven while the Solo reaches my temp and even then I wait a minute before taking a hit. BUT for those who don't want to pre-heat the bowl just wait till it hits your temp and then put the glass draw pipe in and start your session. The other day I finished off a bowl with the straight stem and had the bent one already filled so I just took out the straight stem and put the bent one in and hit right away hamster style and got a nice cloud (Level 4). I didn't expect the result I got to be so cloudy because I'm a creature of habit and have always warmed bowl before starting a session.

Click to expand...

If you don't mind (technically) wasting a little weed, the whole conduction thing has some upside utility. It is nice to turn on a device and wait a couple minutes and know that the first hit is just kinda waiting for you. One thing I do with the INH 05 is turn it on, set it down, and just wait until I can smell vapor. Then I know that first hit is ready, but for sure, it's already cooked/wasted some product.

In general I prefer convection though, even if it means that first hit is small (but tasty). Whether it's clouds or light vapor, the flavor of convection is vastly superior to my taste buds, and taste is my top vapor priority. But that's another thread I guess....

mitchgo61 said:

If you don't mind (technically) wasting a little weed, the whole conduction thing has some upside utility. It is nice to turn on a device and wait a couple minutes and know that the first hit is just kinda waiting for you. One thing I do with the INH 05 is turn it on, set it down, and just wait until I can smell vapor. Then I know that first hit is ready, but for sure, it's already cooked/wasted some product.

In general I prefer convection though, even if it means that first hit is small (but tasty). Whether it's clouds or light vapor, the flavor of convection is vastly superior to my taste buds, and taste is my top vapor priority. But that's another thread I guess....

Click to expand...

Are you talking just about portables here, mitch?

lwien said:

Are you talking just about portables here, mitch?

Click to expand...

In terms of which I prefer?

The only desktops I've used have been convection...but to me (just my taste) I find that all of the convection vapes I've used, portable or desktop, produce tastier vapor than the conduction vapes I've used (which have all been portable). I generally like the Solo flavor, but other conduction vapes I use...not so much. I gather there's enough convection in the Solo to mitigate the conduction flavor effects, but I'm not sure.

Damn, I derailed the derailed thread...

mitchgo61 said:

If you don't mind (technically) wasting a little weed, the whole conduction thing has some upside utility. It is nice to turn on a device and wait a couple minutes and know that the first hit is just kinda waiting for you.

Click to expand...

I was referring to this ^^ mitch and the reason why is that with my convection LSV, I can turn on the device, wait a couple minutes and know that the first hit is just kinda be waiting for me as well.
It's just been my experience that the conduction upside that you are referring to can happen without any conduction going on whatsoever.

lwien said:

I was referring to this ^^ mitch and the reason why is that with my convection LSV, I can turn on the device, wait a couple minutes and know that the first hit is just kinda waiting for me as well.
It's just been my experience that the conduction upside that you are referring to can happen without any conduction going on whatsoever.

Click to expand...

Oh sorry I misunderstood. That's pretty interesting actually...I warm up the VTE (leaving a full load in it for up to fifteen minutes) and it seems to make the first hit a little bigger but not enough to qualify as a large first hit. Maybe I'll crank up the temps and see if I can amplify the effect.

I got some flower to spare, maybe later tonight I'll do a test with the FF.

lwien said:

I was referring to this ^^ mitch and the reason why is that with my convection LSV, I can turn on the device, wait a couple minutes and know that the first hit is just kinda be waiting for me as well.
It's just been my experience that the conduction upside that you are referring to can happen without any conduction going on whatsoever.

Click to expand...

My experience mirrors lwiens. I think it's pretty sweet when you place a loaded room temperature bowl onto a up-to vaping temp EV-2 and pull giant lung busting clouds with zero seconds spent waiting for the bowl or load to heat soak at all. Pure convection is always at the ready if my EV-2 or Underdogs are plugged in and warmed up.

I use my solo the same way and rarely leave the stem in the chamber between hits and never heat the unit up with the stem in it. I don't really 'chase' clouds but still seem to find 'em somehow.

luchiano said:

To really see if the herb is spent would be to put it into your vapexhale and see if any clouds come from the herb, at 190c. My theory is it would be thick clouds because chances are, leaving the herb in the chamber for 12 minutes at that temperature with no air movement, decarboxylated a lot of the cannabinoids. Some thc would have oxidized into cbn as well, giving a more "relaxed" high, but that depends on how much thc oxidized. Try it out and let us know what happens, if you want.

Click to expand...

I ran the ABV from the test through the Cloud at 2:00 (OG version because I like to rock it old school) and got 4 nice fat rips that did me up pretty nice.

So there were definitely plenty of actives left in that roasted load as you suggested. There was some loss to be sure as vapor was escaping through the Crafty during the test and I'm sure some was condensed into the cooling unit as well. But the spent color of the ABV from the test did belie the potency remaining, I must admit.

So the test where the bowl gets loaded up and vape turned on but no hits... isn't it possible that it's not a great test because normally you would be pulling air through thus mitigating the conduction effect... when it's just sitting there the conduction really builds up and gets the bowl to a hotter temp than it would be normally had someone been pulling air through it.

(please forgive me if my science is off, I'm not well versed in sciences)

421 said:

So the test where the bowl gets loaded up and vape turned on but no hits... isn't it possible that it's not a great test because normally you would be pulling air through thus mitigating the conduction effect... when it's just sitting there the conduction really builds up and gets the bowl to a hotter temp than it would be normally had someone been pulling air through it.

(please forgive me if my science is off, I'm not well versed in sciences)

Click to expand...

You are correct that airflow cools off the heater and any surface over which it flows, which is why on some vapes it's important to slow your draw so you don't overwhelm the heater. But it's still a good test vis a vis conduction vs. convection, in a relative sense...a true (or mostly) convection device won't consume weed when heating while sitting idle....whereas conduction will cook all your weed given enough time. The fact that airflow slows down the heater doesn't change the essential relative (to convection) behavior of conduction, with or without drawing.

Back to the point @lwien made above: I ran a little test...I packed an elbow bowl in the VTE, and set the whip up for a first hit. I cranked it to 235 C....and then let it sit for over an hour. (I don't have any willpower...I was hitting the FF while waiting.) I examined the herb after an hour...it was ever-so-slightly less green than it started, as if a trace of chlorophyll was gone. Like the tiniest bit.

I put the elbow joint back on the device for another ten minutes to re-heat in case it had lost some warmth during the one minute I inspected it. That first hit was definitely somewhat primed, as @lwien had predicted...although it didn't seem like a massive conductive hit like I'd get from the INH when it sits for even three minutes. (The second hit, however...whoa.)

But his basic point seems verified....you can indeed get that "conduction upside" in a convection vape, especially if you have the foresight to plan ahead and give your device an extra-long head start.

Overall, score yet another point for convection.

I do that in my sublimator as well, let the load pre-heat for 5 -10 seconds (or longer if it's not fully heat soaked). It takes away from taste a bit, but makes up for this with increased impact

-I'm a noob.
-Tried my buddies Pax. Loved it
-Researched other vapes
-Decided on firefly and purchased one
-Went to his house for a bake off
-When the vapor settled we both agreed completely that the firefly (convection) produced thicker (slightly) and definitely tastier vapor then the Pax.

Like I said, I'm a noob, but these are my real world results. BTW I'm very glad I went with the Firefly. Quality >quantity

Side note for those not getting fat thick clouds with a FF/convection Vape... The softer you draw the thicker and stronger the hit will be. Too much airflow (drawing too hard) in a convection vaporizer doesn't allow the air to heat up enough before it passes through your herb, thus providing less satisfying vapor and unnecessarily fatigued lungs.
When I first got my FF I tried all the methods people were recommending for packing/drawing and my results were mixed at best. With weary lungs and slight frustration I decided to take the longest softest draw I could (I mean literally if you can hear yourself drawing you may be drawing too hard lol) before giving up and going to bed. Next thing I knew I had taken the biggest most satisfying rip I had ever taken on any vaporizer (yes I've tried tabletops too).

Try it folks. Less CAN be more!

Cheers,

-B

So first forgive me for catching up on a 4 page post all in one post but here it goes... I hope that I am not breaking the rules by mentioning the Zion vaporizer in this thread as a manufacturer but I thought it relevant to the topic. Moderators, please let me know if I am out of line.

mitchgo61 said:

A. Try the Firefly. Huge clouds, pure convection, even smaller than the Crafty.

Click to expand...

Not sure I agree... seems like the Firefly Boro load chamber would take on some heat from that 1200 F element especially with the preheat?... I don't own one so I could be wrong.

Abysmal Vapor said:

Do you think that there is such thing as pure convection vaporizer?

Click to expand...

The zion design is close. The heating element is practically "hanging in space" with only incidental contact with eht glass joint insulator tube. I have a dispersion screen (adds turbulence) that we are in the process of optimizing the distance away from the load that it sits. However, it does suggest that he majority of radiation stops inside of a 1/2" from heater element to load. It's my experience that the screen will take on heat making the device less efficient as any heat absorbed by the device is wasted. However, the screen can only take on a temperature less than that of the air steam so the radiant heat is eradicated for the most part. Same with the load chamber, it can absorb heat from the air stream but will always be at a temperature less than the air steam so should have negligible effects the vapor... that is assuming you don't have the bowl intimately connected to the heater device... The Zion does not, same as the solo. Always good to have the load in the removable mouth piece for reason no?
So other than the tiny radiant heat from the dispersion screen in the Zion is pure convection.... Air steam is flowing... button is pressed... heater element only delivers convection heat to the air steam (some inefficiencies through the borosilicate heat chamber minimized by silica & wood insulation) and
passes through the dispersion screen creating turbulence and then entering the load. The button is depressed 3 seconds prior to draw end to remove the heat from the heater extending the draw and minimizing the heat that stays in the device to make it hot. So, in my humble opinion, yes, pure convection However, you can cheat and depress the button and preheat the element with some convection into the boro joint) so that it is "fire hot" ready... I prefer to enjoy the first subtle tastes as the device "wakes up" through the first draw

pakalolo said:

I don't think there's a device out there that moves the load far enough away from the heat source to avoid some radiated heat. Also, as sticks mentioned, inevitably the screen (if there is one) and whatever holds the load heats up and adds a degree of conduction. In some designs—the FV inverted for example—these effects are minimal, but they are still there.

Click to expand...

We are working on this with the Zion to combat high center over darkening. Initially I believed this was radiation effects but I did an experiment where I moved the load far way from the heater and still had the center browning. This made me conclude that it is the velocity drag on the OD of the lead chamber do the laminar flow effects on outer diameters of the load... Thanks @Stickstone for the discussions on laminar flow So, I am now trying some flow disruption / selective blocking theories to try to rid the dreaded center biased dark browning action.

Stu said:

For shits and giggles I sacrificed a bowl of White Fire to run the "no draw for a session" test with my Crafty as I've done with several other vapes.
(Fresh herb on the right for comparison)

Click to expand...

I believe this to be the down fall of the conduction method. Doesn't this mean that as it heats up and when you are not drawing on it the essentials can be wasted vapor? If ABV, is that dark doesn't that correspond to a relatively high temperature? How do you remove chlorophyll without elevating the temp?I need to google chlorophyllase lol. Would be curious to see what an RTD would read if it was placed in there?

So, I think that there is one more category of Vape which is:

5. On-Demand Pure convection vaporizer that has a detachable bowl and is therefore free of any conduction. The convection source could be steady state or on demand so I guess you can argue for two more cats


For me I am an athlete so healthy vapor is my main focus. So, with conduction you always seem to get that last nasty tasting dry your tongue out dirt hit. Its like dark roast verses light roast for me. For me it is more about uniform vaporization in a slow methodical method starting at low temps and sipping my way through a nice load of lavender. Its about the ability to have really fine control and "sneak up" on that delicious golden brown ABV... no bits green, no bits charred. Yum


Don't get me wrong I do enjoy cranking a unit up to 11 and rocking some convection clouds lol.

(Teaser Zion vid...real deal informative video should be out by weeks end)

Nice video RBT ! Would love to try it for myself xhaha.. maybe one day ! Cheers from Bulgaria !
By no pure convection i meant.. that even heated by air herb gets hot and particles conduct heat on each other .. thats why tighter pack often gives better clouds with some vapes .
With my UD if i pack too tight i scortch a load that wouldn't be on that temp if it was loosely packed.

RastaBuddhaTao said:

Not sure I agree... seems like the Firefly Boro load chamber would take on some heat from that 1200 F element especially with the preheat?... I don't own one so I could be wrong.

Click to expand...

It gets hot, but not enough to cook. There is zero conduction happening with the FF....it's buried in this thread somewhere, but several of us conducted "no draw" tests with the FF and found no evidence of passive heating/conduction whatsoever. The FF has some issues, but their claim of "100% convection" does indeed seem consistent with reality.

EDIT: now that I look, it's not even burled....read the top of this page for more detail on this...

mitchgo61 said:

It gets hot, but not enough to cook. There is zero conduction happening with the FF....it's buried in this thread somewhere, but several of us conducted "no draw" tests with the FF and found no evidence of passive heating/conduction whatsoever. The FF has some issues, but their claim of "100% convection" does indeed seem consistent with reality.

EDIT: now that I look, it's not even burled....read the top of this page for more detail on this...

Click to expand...

I was one of the testers.

The FF takes a lot of flak for its supposed learning curve and shitty battery life (don't think I don't notice! ) - neither of which I agree with - but I am certain in my mind it's very, very, very nearly if not all convection.

I'm particularly sensitive to conduction - especially the taste - and I've been using the FF for over a year and never once believed or sensed any discernible conduction was going on.

Of course, I also believe I can taste the difference between butter and "I Can't Believe It's Not Butter," so take it all for what it's worth. I'm also a lowlife drunk with an ax to grind and a chip on my shoulder.

I also believe the neighbor's dog talks to me.

.... Oh yeah, convection makes awesome clouds! I seen 'em! I seen 'em!