Many vaporizer guides reproduce the same chart. It lists cannabinoids and terpenes with a boiling point next to each, which implies that setting your device to a given temperature releases only the compound beside it. A study in Cannabis and Cannabinoid Research (Eyal et al., first published online in 2022) argues that this premise is mistaken. Cannabinoids’ real atmospheric boiling points are far higher than the chart figures. Evaporation happens well below boiling point, and time matters as much as temperature. This article covers the two device categories, what that evidence does and does not support about temperature, and the maintenance that decides how long a device lasts.
Thai context. In Thailand, cannabis flower is a controlled herb under the Notification of the Ministry of Public Health Re: Controlled Herbs (Cannabis) B.E. 2568. It is supplied for medical use only, and may be dispensed only against a prescription on form PT 33 from an authorised practitioner. Each prescription covers no more than 30 days and cannot be refilled. Online sale and advertising of flower are prohibited, recreational use is not permitted, and smoking or vaping in public is restricted. This article is about handling and maintaining devices. It does not encourage recreational use.
1. Vaporizing versus combustion
Combustion (burning) reaches roughly 600–900 °C at the tip of a lit joint, depending on whether the user is drawing. It produces the products of incomplete combustion: tar, carbon monoxide, polycyclic aromatic hydrocarbons and the rest.
Vaporizing heats material until the compounds of interest leave it as vapour, without igniting it. The intended benefit is that you inhale those compounds without the combustion by-products.
Two honest caveats:
“Healthier than smoking” is not the same as “safe.” Vaporizing removes combustion products. It does not remove pesticide residues, mould or mycotoxins that are already in the material. Topic 324 (contaminants) explains why.
Device quality matters. A cheap device with a poorly designed heating path can heat components that were never meant to be heated. In a market with unregulated imports, this is a real risk.
2. The two categories
| Dry herb | Concentrate | |
|---|---|---|
| Material | Ground flower | Extract — hash, rosin, resin |
| Chamber | Larger, packed with plant material | Small, often a cup or coil |
| Typical temperature | Lower | Higher |
| Session length | Longer, multiple draws | Shorter, more intense |
| Maintenance | Regular chamber cleaning, plant residue | Sticky residue, more frequent cleaning |
| Material efficiency | Uses more material by weight | Uses far less by weight |
Heating method matters more than the category label:
Convection: hot air passes through the material. Heating is more even, scorching is less likely and flavour is generally better, but these devices usually cost more. They also respond faster to temperature changes.
Conduction: the material touches a heated surface. These devices are simpler, cheaper and quicker to reach temperature. However, material next to the surface gets hotter than material further away and can scorch, so you need to stir it for even extraction.
Hybrid devices use both methods, as most decent modern dry-herb devices do.
Do not buy a device on the strength of a temperature range alone. A conduction device set to 190 °C is not delivering 190 °C to all the material in the chamber.
3. Temperature: what the evidence supports
The source. Eyal AM, Berneman Zeitouni D, Tal D, Schlesinger D, Davidson EM, Raz N. “Vapor Pressure, Vaping, and Corrections to Misconceptions Related to Medical Cannabis’ Active Pharmaceutical Ingredients’ Physical Properties and Compositions.” Cannabis and Cannabinoid Research 2023; 8(3): 414–425 (first published online 2022). DOI: 10.1089/can.2021.0173.
What the study did. The authors:
- calculated vapour pressures and boiling points from physical-chemistry data (they did not measure boiling points directly, because THC and CBD decompose first);
- re-analysed published data on drying, decarboxylation and extraction;
- ran vaping trials with about 200 mg of ground flower in one medical desktop convection vaporizer (Volcano Medic), at 180–220 °C for 20–180 seconds.
They did not compare consumer devices, and they did not test any user technique. Five of the six authors work for a medical-cannabis manufacturer.
What it found:
- The calculated atmospheric boiling points of THC and CBD are above 400 °C (752 °F) (about 425 °C for THC). The roughly 155–160 °C figure in the charts is a vacuum-distillation value, not a boiling point at normal pressure.
- Cannabinoids and terpenes both evaporate substantially, given time, at temperatures well below their boiling points.
- At 180 °C, the trials measured THC losses of about 9% after 20 seconds and 21% after 40 seconds. The authors extrapolate that THC needs more than 3 minutes to approach complete evaporation at that temperature.
- Monoterpenes evaporated almost entirely, and sesquiterpenes were markedly reduced, before cannabinoids evaporated significantly.
What follows, with appropriate caution. The points below are inferences from that study and from basic physical chemistry. They are not tested user protocols.
Boiling point is the wrong mental model. Evaporation from heated material is a rate process governed by temperature and time. It is not a threshold you cross. A chart that says “linalool: 198 °C” implies that nothing happens at 197 °C and everything happens at 199 °C, which is not how evaporation works.
Session duration is a variable you control. At a given temperature, a longer session should extract more. Thirty seconds at 180 °C is a different extraction from three minutes at 180 °C. If you only ever adjust temperature, you are ignoring half of the equation.
Terpenes come off first, cannabinoids after. This is consistent with what many users describe: the first draws of a session are the most aromatic and the later draws are more cannabinoid-rich. The study’s trials support the order in which compounds evaporate. They did not measure what users perceive.
Start low and step up. Instead of picking one temperature, begin at the lower end of your device’s range and raise it during the session. This approach is consistent with the evaporation order the study describes, but the study does not prove it, because it never tested the approach.
A general working range for dry herb is roughly 175–210 °C, with concentrates typically higher. We are deliberately not giving you a table of compound-specific temperatures, because the study indicates that such tables rest on wrong boiling points and on a threshold model of evaporation.
4. Practical use
Grinding. Grind evenly and moderately fine. You want enough surface area for even heating, but not so fine that the material packs, blocks airflow or falls through the screen.
Packing. Fill the chamber but do not compress it. A packed chamber blocks convection, and a half-empty chamber in a conduction device gives uneven contact.
Moisture content. Over-dry material vaporizes harshly and unevenly. Material that is too moist does not vaporize properly and can foul the chamber. In this climate both problems are common: material dries out fast in air conditioning and absorbs moisture fast in ambient humidity. Store it in a sealed container.
Draw. Draw slower and longer than you would on a cigarette. Vapour production depends on how long the air stays in contact with the heated material.
Stir mid-session in a conduction device.
Know when it is done. Spent material turns brown and the taste fades. Carrying on past that point adds little except harshness.
5. Maintenance
This section decides whether a device lasts two years or six months. Topic bai208 (gear cleaning) covers cleaning in more detail.
After every session, or close to it:
- Empty the chamber while it is still slightly warm, when residue comes out far more easily.
- Brush out the chamber and the screen.
Weekly:
- Clean the screens and the vapour path with isopropyl alcohol on a cotton bud.
- Clean the mouthpiece.
- Check the seals and O-rings.
Monthly:
- Soak removable metal and glass parts in isopropyl alcohol, then rinse them thoroughly with water and dry them completely. The aim is to avoid heating and inhaling leftover alcohol.
- Inspect the battery and charging port.
Never:
- Submerge an electronic device or its battery.
- Use alcohol on plastic parts unless the manufacturer says it is safe, because it can craze and weaken plastics.
- Heat a device that still has alcohol in it.
Battery care. Lithium batteries degrade with heat and with being held at full charge. Do not leave a device charging overnight or sitting in a hot car or direct sun. If you will not use it for a while, store it at about half charge. In this climate, the ambient temperature itself stresses the battery. A device left in a bag in Bangkok in April is being cooked.
6. Buying: what actually matters
Convection or hybrid over pure conduction, if the budget allows.
Precise temperature control, ideally in single degrees rather than three preset levels, if you want to step the temperature up gradually.
Materials in the vapour path. Look for glass, ceramic and stainless steel. Be sceptical of unbranded devices if you cannot find out what the vapour passes through.
Replaceable parts. Screens, seals and mouthpieces should be available. A device you cannot get parts for is a disposable device.
Battery. Replaceable is better than sealed, and removable 18650 cells are ideal.
Reviews from people who have used it for months, not launch reviews.
A note on the regional market. Vaporizers reach Southeast Asia through a mix of official distribution, grey imports and counterfeits. Counterfeits of well-known devices are common. The parts most likely to be substituted are the battery and the vapour path, which are the two that matter most for safety. Buy from a distributor who will honour a warranty, and be suspicious of prices well below the market.
A legal note about the device itself. Thailand bans the import (Ministry of Commerce, 2014) and the sale (Consumer Protection Board, 2015) of e-cigarettes and baraku, and these bans have been enforced against travellers. Whether a particular dry-herb vaporizer falls under them can depend on how customs classify it, so check before you buy, import or travel with one. Lawful access to cannabis does not mean the device is lawful to own: different rules govern each. Singapore, Malaysia, Indonesia and Vietnam impose severe penalties for cannabis offences, and their rules on vaporizers may be stricter still.
7. Concentrate devices specifically
Higher temperatures, because there is no plant material to insulate the extract and the material itself is different.
Small doses. By weight, a concentrate is several times as potent as flower.
Residue builds up faster. Sticky extract residue on a coil or in a cup carbonises if it is not cleaned, and you then inhale it. Clean concentrate devices more often than dry-herb ones. Pre-filled cartridges are a separate subject, covered in bai207.
Material quality matters more, not less. Mechanical separation concentrates whatever was in the flower, including contaminants. This covers dry sieve and water hash (topics 323 and 1315), rosin (topic 1313) and dry ice (bai141). Solventless does not mean uncontaminated; see topic 324.
The regulatory position on extracts is separate and stricter. Under the Narcotics Code and the MoPH Category 5 notification, cannabis and hemp extracts containing more than 0.2% THC by weight are Category 5 narcotics. For the B.E. 2569 licensing changes, which have applied to extracts since 26 April 2026, see topic 1330 and bai209.
8. Summary and over to you
- The boiling-point charts use vacuum figures. The calculated atmospheric boiling points of cannabinoids exceed 400 °C.
- Evaporation depends on time, not just a threshold. At 180 °C, THC is estimated to need more than 3 minutes to approach complete evaporation.
- Monoterpenes evaporate almost entirely before cannabinoids evaporate significantly. Starting low and stepping up is consistent with this order, but it has not been tested as a technique.
- Convection or hybrid, with precise temperature control. Warm-empty after use, clean with alcohol weekly and fully every month, then rinse and dry. Heat kills batteries.
- Vaporizing is not decontamination, and the device has its own legal status.
Has anyone compared a step-up session with a fixed temperature on the same material, in terms of taste, how much material is used and how fast residue builds up? The published finding is that monoterpenes evaporate almost entirely before cannabinoids evaporate significantly. That makes the comparison worth trying, but nobody has tested it as a technique. Practical experience on the device side would be worth reading.
Related reading on this forum: topic 324 (contaminants), topics 323 and 1315 (hash), topic 1313 (rosin), bai141 (dry ice), bai207 (vape cartridges), bai208 (gear cleaning), topic 1330 and bai209 (2026 licensing changes).
This article is general consumer information, not medical or legal advice. In Thailand, cannabis flower is a controlled herb supplied for medical use on prescription. E-cigarettes and baraku are banned from import and sale. Cannabis and hemp extracts above 0.2% THC by weight are Category 5 narcotics. Rules differ across the region. Check the current position before buying, importing or travelling with any device or product.