What Actually Happens Inside Your Vaporizer (It's Not Smoking, I Promise)

The Question Sarah Asked That I Couldn't Answer

About six months after I'd switched to vaporising — so early 2019, because I switched at 34 and I'm 42 now, do the maths — my partner Sarah asked me a question that should have been simple.

And I realised I couldn't answer her properly. I could say "it's healthier" and "it heats instead of burns," but when she asked what that actually meant — what was literally happening to the plant material, where the cannabinoids came from, why smoking produced so much more visible vapour if the vaporizer was so efficient — I just shrugged and changed the subject.

This bothered me more than it probably should have. I work in IT. I'm supposed to understand how things work. I'd been vaping for months, switching my entire consumption method, making decisions about my health, and I couldn't explain the actual mechanism.

Too late, Sarah. The dissertation was already happening.

I looked at laboratory studies, toxicology reports, thermal decomposition data. I read papers from MAPS, NORML, academic journals I barely understood. And I found something interesting: the science of what actually happens inside a vaporizer — and why it makes such a difference — is way more fascinating than I expected.

This is what I found. Apologies in advance for the IT analogies. Sarah has asked me to apologise pre-emptively. Fair.

Before We Go Further: This Isn't What You Think

When someone says "vaping," your brain probably goes to one of two places: those nicotine pod things teenagers keep getting told off for, or the oil cartridge pens that made headlines a few years back for sending people to hospital.

Neither of those is what we're talking about.

Device Type	What It Heats	What's In It
Dry herb vaporizer	Ground cannabis flower below burning point	Just heated plant matter; no carrier oils, no thinners, no PG/VG
Oil/concentrate pen	Distillate, live resin, or other extract	Often diluted with carrier oils or thinning agents; quality varies wildly. Vitamin E acetate cases were oil pens, not dry herb.
Nicotine vape	E-liquid (PG/VG/nicotine/flavour)	Entirely different toxicology — data does not transfer to dry herb

Right. Clarification done. Let's get into what actually happens inside your vaporizer.

Cooking vs Burning: The Only Science That Matters

Here's the core distinction in one sentence: combustion destroys, vaporisation extracts.

When you light a spliff, the plant material reaches temperatures above 233°C (451°F). At that point, chemical reactions kick off — carbon-based material reacts with oxygen, large molecules break apart, and new chemicals get created. Tar. Carbon monoxide. Over a hundred different compounds, most of which you never asked for and definitely don't want in your lungs.

When you use a vaporizer at, say, 185°C, you're staying below that combustion threshold. The cannabinoids and terpenes — the bits you actually want — evaporate off the surface of the plant material as a gas. No fire. No ash. No burning.

Think of it like this. I work in IT. When you want data off a hard drive, you have two options:

• Option 1: Plug the drive in, copy the files, eject safely. The data transfers. The original drive remains intact. You can go back and get more later if you need it.
• Option 2: Set the hard drive on fire and try to read the smoke.

Smoking is Option 2. You're destroying the source material to access what's inside, and you're creating a load of byproducts in the process. Vaporising is Option 1. Non-destructive extraction. You get the data you want, the source stays (mostly) intact, and nothing catches fire.

The number to remember: 233°C. Below that line, you're cooking and extracting. Above it, you're burning and destroying.

Why This Actually Matters: Decarboxylation

Here's something most "what is a vaporizer" articles skip entirely, and it's important.

Raw cannabis flower doesn't actually contain much THC. It contains THCA — tetrahydrocannabinolic acid — which is the precursor compound. THCA isn't strongly psychoactive. You could eat a whole gram of raw flower and feel basically nothing. I would not recommend testing this. Your jaw will get tired and you'll learn nothing.

To convert THCA into the THC that gets you high, you need heat. This process is called decarboxylation — the THCA molecule loses a carboxyl group (releases CO₂) and becomes THC.

Decarboxylation starts happening around 104–115°C and accelerates as temperature rises. At normal vaping temperatures (177–226°C), the conversion is basically complete. You're getting almost all of that THCA turned into usable THC.

Combustion, meanwhile, overshoots the sweet spot dramatically. Yes, it decarboxylates. But it also exposes the resulting THC to temperatures where it starts to degrade and burn alongside everything else. You're using a blowtorch to poach an egg.

Vaporisation sits in the window where THCA efficiently converts to THC, the good stuff releases into vapour, and you're not destroying it before it reaches your lungs.

What's Actually Coming Out: The Numbers

Right, here's where it gets properly interesting. I know, I know. "Dennis is about to cite a study." Sarah has left the room. You're fine.

The most-cited research on this comes from a MAPS/NORML study using a Volcano desktop vaporizer at around 200°C. They analysed exactly what was in the vapour versus what was in smoke from the same cannabis.

Measure	Vapour (Volcano @ 200°C)	Smoke (same flower)
Cannabinoid share of total content	~95% cannabinoids (mostly THC, some CBN)	Non-cannabinoids up to 88% of total content
Identified compounds in output	Trace volatiles, terpenes, plant oils — tiny amounts of unwanted compounds	Over 111 identified chemicals; multiple PAHs (carcinogenic)
Specific smoke toxins (benzene, toluene, naphthalene)	Eliminated	Present

In plain English: vapour is mostly the stuff you want. Smoke is mostly stuff you don't.

This is where the "95% fewer toxins" claim comes from that you'll see quoted everywhere. It's not marketing waffle — it's what the lab work actually showed. Vapour from a quality device is dramatically cleaner in composition than smoke from the same flower.

"But I've Got a Budget Vape, Not a Volcano"

Fair question. Most of the hard data comes from medically certified desktops like the Volcano. Does this apply to your £79 portable?

The honest answer: the exact numbers won't map 1:1, but the fundamental principle holds.

Research on other devices — including the Arizer Solo — showed similarly high decarboxylation rates (97–99%). Meanwhile, a butane flame-based device showed clearly lower efficiency, underlining that design and temperature control do matter.

What makes a vape "good enough" for these benefits?

• Reasonably accurate temperature control
• No obvious hot spots or charring at normal settings
• Produces brown AVB, not black ash
• Doesn't combust at settings where it shouldn't

Many mid-priced portables meet that bar now, even if they're not lab-certified medical devices. If your V3 Pro is producing evenly-browned AVB and not leaving charred black residue, you're vaporising, not burning. The science applies.

The Efficiency Revelation (Or: How Much Weed I'd Been Wasting)

This is the bit that changed how I think about consumption. From controlled testing:

• Vaporizer: delivered approximately 46% of the plant's available THC into vapour (Volcano, three 45-second heat cycles).
• Joint (real-world conditions): often delivers under 25% of available THC, because sidestream smoke — the stuff curling off the end while you're not inhaling — carries away cannabinoids into the air. Plus roach loss, uneven burning, etc.

Under perfect lab conditions, a joint could theoretically reach 70–80%. But nobody smokes in perfect lab conditions. In real life, you're losing half or more of what you paid for into the air. And that's before you factor in the tobacco percentage of a standard UK spliff, which means you're also paying Amber Leaf for the privilege of setting fire to a plant that was never helping you.

Dennis framing: vaporizers deliver roughly double the THC per gram compared to a typical joint, mainly because nothing burns away while you're not actively inhaling.

And then there's AVB. With smoking, your leftover is ash — inert, useless, bin it. With vaping, your leftover is already-decarboxylated plant material that still contains THC. If you started with 20% THC flower, your AVB might still test around 6–8%. Not strong, but not nothing either. That "waste" can go into edibles, capsules, whatever. Your £10 gram does double duty.

I've done the full breakdown on what this efficiency means for your wallet in The Maths of Vaping: How Switching Saves You £1,000+ a Year. Spoiler: it paid for the vaporizer within months.

Why Vapour Smells Different (The Sarah Test)

When I started vaping, my partner Sarah noticed the difference immediately. Not because she suddenly approved of my cannabis use — let's not go mad here, she tried it twice in her twenties, decided it wasn't for her, and has held that position with the patience of a saint ever since — but because the house stopped smelling like a festival campsite.

Here's the science: vapour is an aerosol of tiny droplets and gas containing cannabinoids, terpenes, and plant volatiles suspended in hot air. Almost no solid carbon particles compared with smoke.

Smoke, by contrast, is dense with soot, tar, and combustion byproducts. Those particles are heavier. They cling to surfaces, fabrics, hair. They linger. I used to find old Amber Leaf smell in coat pockets for months after I'd stopped mixing. Like an olfactory ghost of bad decisions.

Vapour dissipates faster because the droplets are lighter. You're smelling intact terpenes and heated plant oils — which do have a smell, don't get me wrong — but it's a toasted, herbal, somewhat nutty smell that clears within minutes. Not the burnt stench that embeds itself in your curtains for days.

The practical upside: I can vape in the living room now. This required negotiation, obviously. Sarah's exact words when I first suggested it were "absolutely not." But once she realised vapour doesn't cling to the sofa or make her clothes smell, the rules relaxed. She still makes me open a window. But progress is progress.

What Happened to My Lungs

I'm not going to claim vaping is risk-free. We don't have 50-year longitudinal studies. Anyone who tells you they know the complete long-term picture is either lying or selling something.

But here's what the evidence we do have suggests:

• Earleywine & Barnwell (2007): Vaporizer users were approximately 40% less likely to report respiratory symptoms — cough, phlegm, chest tightness — compared to non-vaporizer cannabis users, after adjusting for tobacco use and consumption amount.
• 30-day switching trial: Smokers who switched exclusively to vaporizer reported improvements in respiratory symptoms and lung function measures within a month.

I can add my own anecdote, which you're going to get whether you wanted it or not. I smoked spliffs with tobacco for nearly two decades. The morning cough was part of life. I'd accepted it. Three months after switching to vaping (and cutting out the tobacco entirely), the cough was gone. Not reduced — gone. I was 34. I didn't know lungs could actually recover that fast.

I've written about this in more detail in Your Lungs After 30 Days Smoke-Free, including what the first month actually felt like. Short version: rough at first, dramatically better by week four.

The framing here is harm reduction, not harm elimination. You're comparing inhaling heated vapour to inhaling smoke from burning plant matter mixed with tobacco. By that comparison, the respiratory benefits are real and measurable. By the comparison of "vaping vs not inhaling anything," obviously don't inhale things if you don't need to.

But if you're going to use cannabis — and I am, on a UK medical prescription, for chronic pain and ADHD management — vaporising is demonstrably easier on your airways than burning it.

How to Know You're Actually Vaporising

Here's the tangible proof, the stuff you can verify yourself without a lab.

The AVB Colour Test

What You See	What It Means
Light brown to medium brown	Vaporising properly. Cannabinoids extracted, plant matter toasted but not burnt.
Dark brown (at higher temps)	Still fine, just extracted more aggressively.
Black, ashy, crumbly	Combustion. Temperatures too high or device fault. Stop.

Properly vaped herb should be dry and uniformly coloured. Not grey or white ash. Not charred residue.

The Smell Test

Vapour carries a toasted, sometimes nutty or herbal smell that dissipates within a few minutes, especially with any air movement. Smoke leaves a sharp, burnt odour that lingers in rooms, hair, and fabric much longer.

If your session smells like a campfire rather than a bakery, you're burning.

The Visibility Test

At normal temperatures, cannabis vapour is often wispy or lightly visible and tends to disappear within a second or two in moving air. Smoke is denser and hangs in the air much longer.

A Quick Note on Temperature

Different compounds vaporise at different temperatures. This is why adjustable temperature control matters — it lets you customise your experience.

Compound	Approx. Vaporisation
THC	Begins around 157°C
CBD	Volatilises over a higher range, often cited around 160–180°C
Myrcene (terpene)	Mid-160s°C
Limonene (terpene)	Mid-170s°C

Lower temps (170–185°C) tend to give lighter, more terpene-forward sessions — better flavour, more energetic effects. Higher temps (195–210°C) pull more cannabinoids and heavier compounds — bigger clouds, more sedating effects.

This is a simplified version. Actual vaporisation in a packed bowl is influenced by airflow, device design, grind consistency, and time at temperature. It's not just about hitting a magic number. I've written a full breakdown in The Temperature Guide I Wish Someone Gave Me.

The Anatomy of a Vaporizer (30-Second Version)

Before we wrap up, quick overview of what's actually inside these things:

• Chamber/Oven: where your ground herb sits. Usually ceramic, stainless steel, or occasionally glass-lined.
• Heating Element: what generates the heat. Either in direct contact with your herb (conduction), heating air that passes through it (convection), or both (hybrid).
• Airpath: the route vapour travels from chamber to your mouth. Materials here affect taste — glass and ceramic are cleanest, plastic less so.
• Mouthpiece/Cooling: where vapour cools before you inhale. Better vapes have longer or more sophisticated cooling paths. This is why a Mighty+ hits smoother than a budget pen despite similar temperatures.

How the heating works — conduction versus convection — is a whole separate topic, and one of the most misunderstood aspects of vaporizers. That's covered in Conduction vs Convection: The Truth After 8 Years.