Vaping Temperatures - Why Go Higher?

[willieR]

It's pretty clear that many of us have our vapes set higher than required to get what we want. Further, I believe that the presence of non-cannabinoid by-products affects the buzz. These by-products are released at temps higher than THC volatilization and may not be good for us.

...Vaporized cannabis emits a thin gray vapor...

I believe that years of traditional combustion has us trained that a big smoke = big buzz. I'm now thinking that big smoke means we're vaping at some temp in excess of what is necessary to release THC and related Cannabinols.

See here: http://www.montananorml.org/docs/McPartland-Russo-JCANT-2001.pdf

QUOTE:
"Vaporizer technology may improve the bioavailability of limonene and
other compounds, which volatilize around the same temperature as THC (see
Figures 1-3). Vaporizers are smoking apparati that heat cannabis to 185C
(365F), which vaporizes THC but is below the ignition point of combustible
plant material. Vaporized cannabis emits a thin gray vapor, whereas combusted
cannabis produces a thick smoke. Thus, vaporizers deliver a better cannabinoid-
to-tar ratio than cigarettes or water pipes (Gieringer 1996). In a recent
study, traces of THC were vaporized at temperatures as low as 140C (284F)
and the majority of THC vaporized by 185C (365F); benzene and other carcinogenic
vapors did not appear until 200C (392F), and cannabis combustion
occurred around 230C (446F) (Gieringer 2001)."


I've read countless threads where people appeared dis-satisfied with a thin vapor. Then others come in with their adjustable thermostats and say how they have their temps jacked way up to get the desired thick vapor. It seems clear that all they are doing is releasing the Cannabinoids, and then also releasing other compounds hat are clearly not healthy.

For example THC is volatilized at 185C. At 200C Benzene is also volatilized.

 

[IAmKrazy2]

That's why the PD is so nice, low perfect temp every time. No adjustment and a great uppy high

 

[DeepFried]

It's pretty clear that many of us have our vapes set higher than required to get what we want. Further, I believe that the presence of non-cannabinoid by-products affects the buzz. These by-products are released at temps higher than THC volatilization and may not be good for us.
...
For example THC is volatilized at 185C. At 200C Benzene is also volatilized.

I already posted this in response to your same theory in the Iolite thread and will post it here as well:

yes that study [or more accurately..group of studies] has been on forums forever. However if you research a little deeper you will find a lot more studies that also point to higher temps being needed depending on which cannabinoids you wish to release. Case in point, the study you linked to has:

cannabidiol (CBD)
Boiling point: 160-180*C / 320-356 degree Fahrenheit
Properties: Anxiolytic, Analgesic, Antipsychotic, Antiinflammatory, Antioxidant, Antispasmodic

where as a much more controlled measurement has it at 206.3C
http://www.chemspider.com/Chemical-Structure.2446.html

In regards to Benzene, Chemspider lists it as Boiling Point: 78.8 C at 760 mmHg
http://www.chemspider.com/RecordView.aspx?rid=2a57dd4d-0ffe-41f4-aab2-0ceffa91a3f6
so depending on where you read the data from you could be getting Benzene way before even THC vaporizes.

That's why the PD is so nice, low perfect temp every time. No adjustment and a great uppy high

Actually I believe a fixed temp is a big negative for a vape, especially for an experienced vaporist. Based on the facts above it could mean that vapes with a fixed temperature like the Iolite and PD/MZ cannot get hot enough to release the majority of CBD's (and many other beneficial compounds) in your medicine if that is one of the compounds you need.

 

[lwien]

Actually I believe a fixed temp is a big negative for a vape, especially for an experienced vaporist. Based on the facts above it could mean that vapes with a fixed temperature like the Iolite and PD/MZ cannot get hot enough to release the majority of CBD's (and many other beneficial compounds) in your medicine if that is one of the compounds you need.

PD's vape range is between 365f to 395f................wouldn't want to go any higher, imho, due to the increase in toxins.

 

[max]

There doesn't seem to be 100% agreement about where specific compounds are released, temp wise. But it is clear that a few analgesic and sedative compounds are vaporized at higher temps, where you also get a good dose of toxins. According to a well quoted study with the same temp figures the OP is using, benzene is actually present under 200 C. The highest 'clean' temp is indicated to be 365 F/185 C. So there are pluses and minuses to vaping at higher temps and it's up to each person to decide how high of a temp to use. People who need mj for pain relief and sedative purposes get benefits from higher temp vaping, and for them it's worth it to put up with low doses of toxins as a trade off.

"Significant amounts of benzene began to appear at temperatures of 200 C."
http://www.canorml.org/healthfacts/vaporizerstudy1.html

Moving from smoke to vapor is an adjustment for a lot of people. Some really like the stupor effect you get with smoke and all its toxins. High temp vaporizing allows for an easier transition, and even if an individual continues to vape at high temps, it's still much healthier than smoking.

 

[willieR]

We (including me) may be confusing terms. Flash temp, Vaporization Temp, and Boiling Temp are three different things. Flash and Vaporization points are lower than Boiling point.

Maybe we're (me) interchanging the terms Flash and Vapor here. The flash point of a liquid is generally defined as the lowest temperature of a liquid, as determined by specific laboratory tests, at which the liquid gives off vapors at a sufficient rate to support a momentary flame across its surface.

I don't think the previous link was referring to this specific Flash point criterion. I'd have to back and see. So not thinking the original data is invalidated, but I'm compelled to go back and re-read. Thanks
So that's all the thought I have into this. I really appreciate the link. If I have more info I'll post it.

 

[willieR]

max that's a good summary. And I agree with DF that an ability to dial in the session based on temp and the different volatilities is desirable. Makes me think of the Bud Toaster design by Hippie Dickey. Have a really accurate thermometer at the point of vaporization would really be the nuts.

 

[Beezleb]

For those looking at vaporizers for pain management I tend to recommend a temperature adjustable vape. I have assisted almost 15-20ish terminally ill/very ill people select vaporizers. The higher end temperature settings are more effective at pain relief. Not really certain of all the scientific reasoning for it but it is a fact that I have witnessed first hand in more than a few people.

If you look at the set temperature vapes you will see that more than a few people try to make the vape hotter by using a can cozy to prefer to use it via a car battery because it is hotter. I know I really do not care for things that come pre-set at what is "best" in the view point of others as it takes out all personal preference in the temperature regard. To me this is limitation.

However, some others really like this manner of vaperizer and for those who prefer a more simplified process this is ideal and in my view is a great starter vaperizer. I tend to think of it like a vehicles transmission, some people like automatics and other like stick shifts.

I recommend these style of vapes, like the PD and MZ when a person is looking for a vaperizer that will vape small amounts better than others and/or if the persons wants fit the mold to speak.

On the other hand, these style of vapes tend to leave the abv at a higher quality than say a temperature adjustable vape but it all comes down to how far vaped the temperature adjustable vape material is. I use a DBV and typically my abv is drained more than say compared to a set vaperizer temps. This is pretty much why people will own a PD/MZ along with and in conjunction with a temperature variable vape to reuse the abv.

 

[Hippie Dickie]

i have the Bud Toaster temp set such that when i look at the ABV there are damn few trichomes left. Currently, for this batch of bud, the setpoint is 445F, according to the digital thermometer.

Now, this is the temperature of the outside of the oven tube. i still prefer to have only glass in the vapor path, so both the control thermocouple and the thermometer thermocouple are outside the vapor airflow. i'm sure there's a thermodynamic equation that can calculate the temperature of the air that flows on the otherside of the tube wall.

There's also a "translation" problem -- the control thermocouple is bare while the thermometer thermocouple is in a glass bead. So the thermometer lags behind the computer by a second or two.

i'm getting a bit thicker than a thin gray vapor -- more whitish, i'd say.

imho having an adjustable temperature control is vital. The BT "remembers" the setpoint for each new session (written into EEPROM in the microprocessor controller), so in operation, it works like a pre-set (fixed) temperature vape.

i've just discovered that i've been loading too much crumbled bud into the vial. i'm using only 1/3 the amount and getting a much richer high.

 

[willieR]

What is the temp range HD?

 

[Hippie Dickie]

it is very easy to hit 550F, at which point the thermometer reads "XX", so i don't know the upper limit.

i think Bubar can hit 1000F (the coil glows) without breaking a sweat -- he's using 12v to feed the heater rather than my puny 6v.

 

[willieR]

Ya, but what's the range? The lower temp range? Maybe it goes to zero.

 

[Hippie Dickie]

i never run it below about 400F, but i assume room temperature is the lower limit -- or whatever setpoint is selected.

 

[DeepFried]

One of my favorite threads on this subject was posted by Dr. Paul Hornby on the GreenCross forums. I like it because it is a very scientific, fully measured account of vape temps with a modern vape- the volcano. Here is a snippet of one of the posts, but make sure to read the whole thread as it is very informative and clearly enforces the notion that you need temps above 190C (for THC anyway).

http://www.greencrossofbc.org/forum/viewtopic.php?id=21&p=1

We ran three separate experiments at Volcano settings 6, 7.5 and 9. At each test, the same
weight of cannabis was placed in the volcano and two bags vapped for the same time period.
Following vaporization, the carcass (sample left behind), for each temperature setting was analyzed
for the three most abundant cannabinoids.

We will attempt to tabulate below our experimental results.


Volcano Setting THC remaining mg/g CBN remaining mg/g CBD remaining mg/g

6 260 0.05 0.6

7.5 245 0.05 0.6

9.0 75 0.05 0.15

 

[lord]

benzene is actually present under 200 C. The highest 'clean' temp is indicated to be 365 F/185 C.
"Significant amounts of benzene began to appear at temperatures of 200 C."
http://www.canorml.org/healthfacts/vaporizerstudy1.html

Thanks for that information, max...

PD's vape range is between 365f to 395f....

I didn't realize the PD was that variable. I don't like going past 190C...

 

[willieR]

I would comment that I have a lot of bud and am not concerned with methods to achieve complete extraction. Just looking for the buzz I want without as much of the harmful carcinogens.

I'm at a loss as to why the two studies are so extremely different with respect to these basic measurements.

Dr. Hornsby had some posts in an internet thread prominently oriented around the Volcano. Not that this point matters or means anything. Just an observation. We're taking Hornsby's word for all of this. I have no reason to doubt what he says, but this isn't a traditional method of communicating research results. I would note that he went out of his way to explain this informality, however. He's sure not to be faulted with leaving out that detail.


McPartland and Russo authored a bona fide technical research paper, peer-reviewed and fully referenced. If I had a gun to my head and was asked which data was more accurate I would say This paper offered more credibility.

THC: Hornby says 200C , and other study says 157C for D9, 178C for D8
CBD: Hornsby says 190C, and the other study says 180C
CBN: Hornsby says 185C, and the other study agrees

Again, not sure what is up.

Some interesting hilites of both referenced studies:

-Clearly time is an issue to allow for a more complete release of material.

-Also interesting are the discussions of the essential oils that vaporize at quite low temps and the euphoria from just those.

-Interesting the various discussions of the blending of THC and CBD, CBN to change the buzz.

- I found the requirement for de-carboxylization of THC (low temp reaction) to allow it to work interesting.

I suspect there are terminology issues in play here. In truth, vapor is created far below the boiling point. Once you get above absolute zero you have the opportunity for some molecule to leave the pack and enter the air (vaporization). Vapor and gas are not the same. You can have water vapor below the boiling point, so I'm not certain what "vaporization point" even means or how it's measured. I suspect that the actual metric is boiling point and we often say vaporization point.

Maybe

 

[nicelytoasted]

Good points willieR.

The boiling points are different than the temperatures that we are thermally desorbing the compounds from our herb, whether by vaporization or sublimation, imo. These temperatures can also be affected by atmospheric or actual pressure at the bud. I believe that partial pressure created at the bowl (when drawing or forcing air across it) determines whether vaporization or sublimation occurs.

Some of the confusion regarding the thermal desorption temperatures listed for THC is because there are many different types of THC, imo. Delta 1,3,8 or 9 indicates the position of the double bond in the molecule, which affects these temperatures. AFAIK, most sources state the temperature of all THCs as delta-1 THC since it is first on the list @ 200C (392F). Since delta-9 THC is by far the most predominant and pyschoactive THC, I believe that it's desorption temperature of ~ 157-160C should be used for vapourizing reference purpose.

My

 

[willieR]

Interesting thought about the temps, NToast. I haven't seen anything on the other THC configs.

 

[Beezleb]

The absolute best temp would always be changing dependent upon on the plant material in terms of dryness, consistency and even the strain I would imagine as far as what is scientifically the most optimum for what your looking for.

Good luck to you in your search but for me, that takes all the fun out of vaping.

 

[Hippie Dickie]

i agree with Beezleb about needing a dynamic adjustment based on physical properties of the bud. i think the PIC can detect some of this and automatically adjust the temperature to compensate. But the state of battery charge has an effect, too. i need to add some more AI to the algorithm.

 

[stinkmeaner]

It is nice to raise the temp as the session progresses to penetrate further into the herbs, if the temp is set too low you might just be vaping the outer layers.

 

[willieR]

I think that's a big part of it StinkM

 

[Hippie Dickie]

i see the temperature rise very slowly, by 1F to 1.5F, during a 20 second toke.

i'm not sure if that's from a "venturi" effect that raises the temperature, or the temperature control algorithm is over compensating for the cooling effect of the air flow.

i can see there is a lot more testing to do ... many more theories to explore.

 

[nicelytoasted]

It is nice to raise the temp as the session progresses to penetrate further into the herbs, if the temp is set too low you might just be vaping the outer layers.

Raising the temp doesn't necessarily increase the penetration into the herb. However, it does allow for a different proportion of actives to be released. As you raise the temp, you get more of the higher boilers from the herb, which changes the effect(s), and hence the experience, imo.

 

[Hippie Dickie]

it seems to me that as vaporization occurs, the temperature at the bud surface will drop, so increasing the temp will allow deeper heat penetration.