Low pressure, worth? Should we be capping our ball vapes?

[MTpromises]

Hi - John here from Vestratto

You don't know me very well yet. You can learn more about me if you want by googling "john mumford xltek" to see my background. With that I hope you will see that I am serious about what I'm doing here. I am trying to help advance new ideas in the cannabis vaporizer world. You may not agree with me and I'm totally willing to be proven wrong but I am not a snake oil salesman.

The original science this post, and the Anvil airflow design, is based on is not mine but was developed by the cigarette industry in its investigations of nicotine bioavailability and cigarette design. In designing Anvil many investigations of parallel technologies took place.

As you lower the pressure liquids boil at a lower temperature because it takes less energy for the molecules to escape. Its why in movies about mountain climbing the tea never gets hot despite boiling vigorously in the kettle. The average human generates a Maximum Inspiratory Pressure of about 80 cm/H2O. That's how hard your diaphragm can pull when you inhale. This is negligible industrially but if you've ever had to explain a hicky you know its very real. Think of an aerosol cloud as balls. Some particles are big, basketballs while some are small, marbles. As you inhale the basketballs in the cloud would get stuck in your mouth or your throat. The golf balls could go much deeper. Marbles deeper still.

Closing down the air valve on an Anvil and pulling hard with your diaphragm will decrease the pressure in the herb chamber by 80 cm/H2O resulting in a small statistical shift in the size of the aerosol particle mix towards smaller particles. These smaller particles penetrate perhaps only one bronchiole branch deeper in the lungs but that is huge in bioavailability because it doubles with each branch. With Anvil we can't generate an ideal aerosol - because we are powered by human lungs - but we can optimize the engineering and apply basic physics to improve the results. We are trying to, even if only by a small amount, shift some "basketballs into golf balls into marbles".

Sorry for the wordy quote, but this comment by Mr. Vestratto here has stuck with me. Is there value in creating low pressure? I've been doing it with my ball vape, using a flat stone pipe to block the top air inlets and rocking it like an airport on a Dynavap. I honestly think there is value here.

 

[Canna Chameleon]

IMHO, Mr Vestratto Anvil thinks more of his science than is necessary.

Considering a $15 copper sleeve reproduced 95% of his engineering impact, I’d take what he says with a grain of salt.

 

[Grass Yes]

Sorry for the wordy quote, but this comment by Mr. Vestratto here has stuck with me. Is there value in creating low pressure? I've been doing it with my ball vape, using a flat stone pipe to block the top air inlets and rocking it like an airport on a Dynavap. I honestly think there is value here.

I am also extremely dubious of this quote, but I'm curious: what have you observed? What are you hoping to accomplish and how are you measuring the result? John's description above was part of a sales pitch with no connection to any concrete changes made to the Anvil design. Are you looking to improve your high? Overall vapor efficiency?

 

[CANtalk]

Sorry for the wordy quote, but this comment by Mr. Vestratto here has stuck with me. Is there value in creating low pressure? I've been doing it with my ball vape, using a flat stone pipe to block the top air inlets and rocking it like an airport on a Dynavap. I honestly think there is value here.

just my , probably not for most people... however everyone is different & there's a range of vapers out there. A high performance heater & low air pressure is how VapeXhale EVO made its name with the glass bamboo pathway . Though afaict its venturi setup in the heater is much more efficient than capping.

 

[MTpromises]

IMHO, Mr Vestratto Anvil thinks more of his science than is necessary.

Considering a $15 copper sleeve reproduced 95% of his engineering impact, I’d take what he says with a grain of salt.

TBF the Dynavap already offered the the pressure change by default with the air-port/cap. I don't know anything about the development of the Dyna, for all I know they looked at the same tobacco industry research he did.

I am also extremely dubious of this quote, but I'm curious: what have you observed? What are you hoping to accomplish and how are you measuring the result? John's description above was part of a sales pitch with no connection to any concrete changes made to the Anvil design. Are you looking to improve your high? Overall vapor efficiency?

I just want to get as high as I can without making the vape taste like burnt popcorn. And it is hard to judge exactly, but it is winning the "reach test" so to speak. I do feel like I'm getting a little more in the head, it's just hard to say if it's psychosomatic/placebo effect, an effect of pulling different/head rush (I don't think so) or real change. I'm asking because I'm not a 100% sure.

 

[Grass Yes]

I do feel like I'm getting a little more in the head, it's just hard to say if it's psychosomatic/placebo effect, an effect of pulling different/head rush (I don't think so) or real change. I'm asking because I'm not a 100% sure.

I would suspect that adding a cap would function similar to a carb, adding some restriction and thickening the vapor. Some people like a lot of restriction although I have not found it useful on my ball vapes. It probably matters which device you have, I suppose.

I'm pretty dubious of claims about low pressure with a carb cap, especially because it seems like this has never been confirmed. But if you like it, keep at it! It can certainly be beneficial even if the reason isn't some kind of bioavailability marketing speak.

 

[GoldenBud]

Sorry for the wordy quote, but this comment by Mr. Vestratto here has stuck with me. Is there value in creating low pressure? I've been doing it with my ball vape, using a flat stone pipe to block the top air inlets and rocking it like an airport on a Dynavap. I honestly think there is value here.

it has nothing to do with pressure. read here

Volumetric flow rate - Wikipedia

en.wikipedia.org

for changing pressure you need a power, electricity. not some torch heating or how the vape is built
it's not an easy task to change the pressure, he also was saying his vape is mostly convection, but the Anvil is mostly conduction..
idk how much he really knows about physics/heat transfer

 

[jardri]

Hello frients! Wanted to share my experience in this regard:

I have several Dynavaps, a Danivape v3 ti and a coppercore Anvil and i can assure you the Anvil has a totallly different behaviour than the other 2. I don´t know why people tend to compare them as the Anvil is really mostly convection. Also, the negative pressure helps a lot in lowering the compounds boiling temperature and the narrowing and opening of the vapor path helps in breaking vapor particles into finer ones which enter deeply into your lungs.

This mix of principles was first acquired by the Sublimator and can sort of be replicated with a capped Flowerpot or similar injector vapes. The Anvil also replicates these penomena.

Dynavap Danivape and similars are not so complicated. They take advantage of negative pressure if the users want but not to such a measured and stable degree, and they tend to heavily rely on conduction and mass. I could not tell which is better (depends of the person, i almost havent used my Dynavap or Danivape since i had the Anvil) but i can firmly say that they dont even work remotely similar. The looks and the heating can be misleading this time because what´s going on underneath is totally different as how is the heat transferred to the herb and how is that product entering your system.

A lot of hate has ben spilled over Vestratto´s John attitude and while i can´t say his mannerisms are alright, i do believe he speaks the truth about how different his device is compared to almost anything in the market. My experience has verified his statements.

So returning to the main topic, yes, negative pressure is good! a little vacuum spices things up and almost every vaporizer uses it in some way, but the most usual is restricting air entrance. I use my flowerpot capped almost 100% of the time because it helps in getting monster clouds with fast inhalations, as I close the airports in my dynavaps.

Have a nice day!

 

[dman28]

The more inspiratory effort required to draw an aerosol into the lungs also reduces the capacity to get it to lower areas of the lungs due to the amount of turbulence that is produced. So more inspiratory effort required for inspiration will theoretically reduce deposition in the alveoli as our lungs have natural defense mechanisms. ie..small, smooth walled respiratory conducting airways will collapse not allowing gas to enter the lower parts of the lung where gas exchange takes place and turbulence produced by the effort has a tendency to "rain out" or be deposited in conducting airways where there is low to no uptake of any aerosol.

 

[dman28]

So it is better to have less inspiratory resistance.

 

[GoldenBud]

I have several Dynavaps, a Danivape v3 ti and a coppercore Anvil and i can assure you the Anvil has a totallly different behaviour than the other 2. I don´t know why people tend to compare them as the Anvil is really mostly convection. Also, the negative pressure helps a lot in lowering the compounds boiling temperature and the narrowing and opening of the vapor path helps in breaking vapor particles into finer ones which enter deeply into your lungs.

1. there isn't a negative pressure. for negative pressure you need to invest energy. there isn't an energy input of any kind in the Anvil other than the torch which raises the T, not the P
2. the Anvil is a conduction vape (when you heat at the notch, below the bowl, the bowl also gets warmer (Fourier law) but the gap of air between the bowl to the metal saving it from getting combusted. it's a conduction vape and the taste doesn't lie - the hits are huge but the taste is muted, unlike convection devices.
3. maybe the air is getting heated a bit but not to be mostly convection imho. it's difficult to check the bowl's temp before a draw, but somebody should do it.

This mix of principles was first acquired by the Sublimator and can sort of be replicated with a capped Flowerpot or similar injector vapes. The Anvil also replicates these penomena.

I don't think so. the Sublimator heater is much, much, much bigger. also FP or GS etc'

So returning to the main topic, yes, negative pressure is good! a little vacuum spices things up and almost every vaporizer uses it in some way, but the most usual is restricting air entrance. I use my flowerpot capped almost 100% of the time because it helps in getting monster clouds with fast inhalations, as I close the airports in my dynavaps.

negative pressure has nothing to do with the Anvil. for making negative pressure you need to invest energy. which energy you invest here except torch heating which raises the T, not the P?


I think the Anvil is just like a bigger Dynavap. small device, torch, heating a bit in a lower position other than the Dynavap, there's a gap of air between the bowl to the shield, but it's kinda the same. a bit bigger heater, more distance, bigger clouds, mute or almost mute taste at super high temp (not combusted)


When somebody climbed on a high mountain and the water boils at 70c-80c temp and not 99c, imagine how much energy he invested to get on this mountain. how that has to do anything with the Anvil? which energy is being invested? nothing...

 

[jardri]

1. there isn't a negative pressure. for negative pressure you need to invest energy. there isn't an energy input of any kind in the Anvil other than the torch which raises the T, not the P

That is not true my friend. Negative pressure means that there is a deficit of pressure between the input and the output. A simple straw generates negative pressure.

2. the Anvil is a conduction vape (when you heat at the notch, below the bowl, the bowl also gets warmer (Fourier law) but the gap of air between the bowl to the metal saving it from getting combusted. it's a conduction vape and the taste doesn't lie - the hits are huge but the taste is muted, unlike convection devices.

The Anvil heats the herbs to a temperature prior to vaporizing so it could account as a minimal conduction involved. But the heavy work is done purely by convection which differs on how a vapcap works. About taste, it is totally convective and the mute you talk about is mainly because of how much dissipation and mass the stock stem gives but with the usa kit with a glass wpa gives all that tasty convection flavour back.

3. maybe the air is getting heated a bit but not to be mostly convection imho. it's difficult to check the bowl's temp before a draw, but somebody should do it.

The anvil clicks when the herb is at a given temperature, it works different than a vapcap.

I don't think so. the Sublimator heater is much, much, much bigger. also FP or GS etc'

It can be smaller but work the same way

negative pressure has nothing to do with the Anvil. for making negative pressure you need to invest energy. which energy you invest here except torch heating which raises the T, not the P?

Your lungs are the ones making that negative pressure just by inhaling as strong as you are confortable with. The stronger you inhale the tronger the vapor will be. If you are a sipper vaporent, you are likely not taking any benefit from this effect.

 

[jardri]

The more inspiratory effort required to draw an aerosol into the lungs also reduces the capacity to get it to lower areas of the lungs due to the amount of turbulence that is produced. So more inspiratory effort required for inspiration will theoretically reduce deposition in the alveoli as our lungs have natural defense mechanisms. ie..small, smooth walled respiratory conducting airways will collapse not allowing gas to enter the lower parts of the lung where gas exchange takes place and turbulence produced by the effort has a tendency to "rain out" or be deposited in conducting airways where there is low to no uptake of any aerosol.

Well that is very interesting indeed because it could explain why i always tend to fill the bong with vapor, remove the vape and then inhale the whole. Maybe the best of both worlds?. You sir have given me some experimentation homework to do

 

[GoldenBud]

That is not true my friend. Negative pressure means that there is a deficit of pressure between the input and the output. A simple straw generates negative pressure.

Joh doesn't speak about the Pressure you make when you draw? he's talking about how his device is build?. the pressure is P=1atm inside , outside of the Anvil. no difference.

John:
"
Closing down the air valve on an Anvil and pulling hard with your diaphragm will decrease the pressure in the herb chamber by 80 cm/H2O resulting in a small statistical shift in the size of the aerosol particle mix towards smaller particles. These smaller particles penetrate perhaps only one bronchiole branch deeper in the lungs but that is huge in bioavailability because it doubles with each branch. With Anvil we can't generate an ideal aerosol - because we are powered by human lungs - but we can optimize the engineering and apply basic physics to improve the results. We are trying to, even if only by a small amount, shift some "basketballs into golf balls into marbles".
"

I don't believe it's true. the P=1atm exists inside, outside, between layers, nothing is changed.

The Anvil heats the herbs to a temperature prior to vaporizing so it could account as a minimal conduction involved. But the heavy work is done purely by convection which differs on how a vapcap works. About taste, it is totally convective and the mute you talk about is mainly because of how much dissipation and mass the stock stem gives but with the usa kit with a glass wpa gives all that tasty convection flavour back.

not only the herb's taste is muted, even the taste is muted for a rich bubble hash (!)

The anvil clicks when the herb is at a given temperature, it works different than a vapcap.

still conduction vape small heater low surfance area other than FP/GS/ELEV8R etc

Your lungs are the ones making that negative pressure just by inhaling as strong as you are confortable with. The stronger you inhale the tronger the vapor will be. If you are a sipper vaporent, you are likely not taking any benefit from this effect.

no, same P=1atm, the velocity is something else. you are confusing Pressure to Velocity of the draw.
on the mountain of Everest the P=0.33 atm, if you're not on some tall mountain the P is usually 1atm
EDIT:
you use force so you also use pressure to take the draw. (pressure equals to force by area)
but then why John mentioned the high mountain?
to tell that if you're on a high mountain you need less butane to get the point?
or he was saying that something inside the Anvil has lower pressure than other part?

 

[Izan]

...so an aerosol and smoke have the same particle size and behave the same when entering the body...

Wicked pissa' presumption....Gotta get me some popcorn.




Cheers
I

 

[Old Moderate]

In all cases, we are mobilizing compounds of interest (cannabinols, terpenes, water…maybe also considered of interest) through evaporation…not boiling. The boiling temps typically presented on internet sites for cannabinoids of around 150-190C are for near zero pressure (not atmospheric or ‘normal pressure’). The normal boiling points for THC and CBD are estimated above 400 C or so…much higher than combustion of plant materials. So, evaporation is the mechanism important for getting us those compounds and evaporation is controlled by vapor pressure (along with surface area, wind speed, etc.). Importantly, Vapor pressure is almost completely independent of total pressure, so any small vacuum created through inhalation should not directly alter evaporation rates except by decreasing the gas phase concentration of cannabinoids, which would happen anyways as air is drawn into the chamber. If a device uses low pressure to accelerate the air, this should promote more evaporation, but indirectly through the faster removal of the compounds.

 

[Farid]

When trying to characterize a device as "convection" or "conduction" heat transfer models are the only thing that should be referenced. Until someone models the device and runs a FEA it's all just speculation.

That said, these discussions are always plagued by a bizarre psychological component. The forum consensus is that convection is superior to conduction and thus if a person likes a device they often see any argument that a device is conduction as a dig at the device.

It's true that convection is likely to produce good flavor because the heat is applied right at the inhale, meaning there is no flavor degradation prior to the inhale. But rapid conduction heating can produce the same results. It's difficult to do, but that's the reason devices like the vapman have good flavor despite being conduction.

So using something as subjective as flavor to try and characterize heat transfer type is not really useful. Especially when everyone is using different flower that will produce different flavors when heated in different ways. In extreme cases it can be helpful (for example when a very "roasted" taste is produced it's probably an indicator of conduction), but for these debated cases it doest really provide much.

 

[GoldenBud]

When trying to characterize a device as "convection" or "conduction" heat transfer models are the only thing that should be referenced. Until someone models the device and runs a FEA it's all just speculation.

true, and the question which I ask - what's the temp of the bowl when you heat the anvil? it's so small, I am pretty sure the bowl's temp is higher so the bowl is hot - not the air...

 

[Farid]

If the bowl was held in place by an insulating material I'd be more prone to believe that convection played a bigger role. But with the bowl being a relatively thin piece of metal I'm not sure. Then there's the question of how much of an effect the cutouts have. But I wouldn't be shocked if a FEA model proved there's a large convection element, I'm open minded.

The anvil clicks when the herb is at a given temperature, it works different than a vapcap.

This is pure marketing language. The anvil clicker works exactly the same way the vapcaps clicker works. Because it has a higher mass the click may happen at a more easy to dial in range, but it works exactly the same as the vapcap. The click happens when the clicker gets to a certain temperature. Nothing about the anvil measures the temperature of the weed itself. The only difference is that the vapcap houses the clicker in the cap, but the cap/tip assembly heat together, and the click is absolutely dependent on bowl temperature.

All that said, the notion that the anvils clicker is tied to the herb temperature would disprove any convection, since with a convection vape, the herb should not be heated to vaping temps until you inhale. And the Anvil clicks before you inhale.

 

[GoldenBud]

we need somebody with the right equipment to check the bowl's temp before the draw. i am sure somebody in the forum has the equipment but maybe he doesn't have the Anvil

 

[Farid]

Modeling it with FEA software would be much better. Setting up a controlled experiment is difficult, especially in such a small area.

Back to the OP, I suspect that the benefit of the restricted flow has very little to do with the pressure drop effecting boiling points, and infinitely more to do with vapor not being diluted with air. Additionally limiting the flow of input air will limit the convective cooling effect that happens in conduction vapes where the air entering the system is cooler than vaporization temperatures. That's why good conduction vapes preheat the air to some extent, to reduce this effect, but I do not consider that to be a "convection vape" because the convection is not bringing enough heat to actually contribute to vaporization, it is just reducing the cooling effect that would otherwise be present without any sort of preheat. Examples of this are the air traveling through the helical grooves of a Dynavap tip, or the air traveling over the heating element of an Arizer vape.

With a convection heater, restricting the flow has the additional effect of the air being more efficiently heated when there is a smaller volumetric flow rate of air traveling through the heater.

 

[Momor]

The click happens when the clicker gets to a certain temperature. Nothing about the anvil measures the temperature of the weed itself. The only difference is that the vapcap houses the clicker in the cap, but the cap/tip assembly heat together, and the click is absolutely dependent on bowl temperature

The difference here is that according to Vestratto, the click doesn't happen at the same temp as a DV cap. In the Anvil the click should happen when the herbs have reached decarboxylation temperature and not vaporisation temperature. So same mechanism that clicks but not at the same temp. The clicker has been made to click at a precise temp, that's what measure the temp of the weed and it seems to be much much more precise that the DV caps (cool caps, hot caps, having to go past the click etc.)
Here you can see the herbs taken out of the Anvil bowl after heating it in order to ride the line. Herbs are very lightly toasted right after the click but will get black if I draw.

https://imgur.com/a/6mdflUo

IME you also achieve better results/extraction with the airflow open vs closed. Doesn't that mean that there is a good role of convection heat ?

Edit: sorry for being quite of topic

 

[GoldenBud]

reached decarboxylation temperature and not vaporisation temperature

which mechanism he uses to know when the carboxyl group had been released, and CO2 is leaving from the THCa molecules? it's very hard to detect it.
I doubt this is how it's done, maybe he said so, but I didn't see any proof of it... things are being said may be bro-science just to sell more, I'm sure you well aware of this too...

if you're meaning that he calibrated the click mechanism to be around 115C, decarboxylation temperature, I don't think it's true. you heat the notch of the Anvil with a torch that has around 800c-100c temp for 25-30 seconds. the bowl's temp imho is much higher than 115c. again , needs to be checked with the right equipment, but I don't think after 30s it's only 115C in the bowl. maybe 150C++

for Dynavap, yeah, it's 170c/180c/200c at the clicks's point , but I think think Anvil is around 115c at the bowl. it must be higher. small system with a heater of 900c~

not speaking about that because the system is so small, the air can't reach temp of 200c or so. these huge clouds must happen because the bowl is at temp of 150C+++

we need to find somebody with the right equipment to check the bowl's temp once the click has arrived. we gotta find somebody. my bet it's almost 100% conduction vape. it's not possible that the taste is SO muted and the clouds are huge, it must be almost 100% conduction or so. maybe not 100% but far from 50%/50% convection:conduction

EDIT:
I don't think the cap clicks at 115C because I also vaped high quality iceolator in the Anvil and it gave huge clouds without taste too. and for hash you need higher temps than herb......


just think about it : it's a smaller system, you heat the notch with a torch, 800C-1000C temp, the bowl can't be held only at 115C until the click, 25s-30s, it's impossible, the metal conducts to the bowl too....

 

[Haze Mister]

Sorry for the wordy quote, but this comment by Mr. Vestratto here has stuck with me. Is there value in creating low pressure? I've been doing it with my ball vape, using a flat stone pipe to block the top air inlets and rocking it like an airport on a Dynavap. I honestly think there is value here.

In my experience with trying this with my ball vapes, it promotes combustion. You would have to design some very clever device to create low pressure in the herb chamber without restricting airflow through the balls. Capping the injector or carbing the rig basically slows down the air flowing through the injector, and needs a lot of practice to avoid combustion or low vapor output.

Ball vapes are designed with the airflow that they have on purpose... When you inhale you do create low pressure in the herb chamber so I don't think there is much room for improvement there without getting really hi-tech with cumbersome devices.

 

[Ramahs]