BlogHow do dry herb vaporisers work?

How do dry herb vaporisers work?

6 min read

Emily Ledger

Why can medical cannabis flowers be prescribed to be vaped, but not to be smoked?

Humans have been using the cannabis plant for thousands of years. We have found ways to utilise the crop and its derivatives for everything from building materials and clothing to medicine, food, and recreation. This diverse plant can be consumed in a variety of ways, including as drinks and edibles, through topical application, and of course, via smoking. 

In fact, smoking remains by far the most popular way to consume cannabis. A 2022 survey of cannabis users in Canada (where cannabis has been legal for recreational purposes since 2018) found that 70% of past-year consumers reported smoking as their preferred method of consumption. Yet, there are signs that the tide is changing.

In this article, we’re taking a closer look at dry herb vaporisers to understand how they work, and the benefits of vaping medical cannabis.


What is a dry herb vaporiser?

A dry herb vaporiser is an electronic device that offers an alternative method to inhale cannabis. 

Like smoking, vaporising applies temperature to dried cannabis flower to release the active compounds within. The resulting vapour can then, like smoke, be inhaled into the lungs where cannabinoids and terpenes are absorbed into the bloodstream. However, unlike smoking cannabis joints, bongs, or pipes, vaporisers utilise vaporisation as opposed to combustion. 

As inhalation has been proven to be the most effective way to consume cannabinoids such as CBD and THC, there is no surprise that weed vaporisers are becoming an increasingly popular option. 

How do dry herb vaporisers work?

Like other kinds of vaporisers, including oil pens and wax pens, dry herb vaporisers apply heat to the consumable products (in this case, dry cannabis flower) to prompt the vaporisation (the transition from liquid to gas form) of the active ingredients within.

Most dry herb vaporisers feature a “chamber” where ground cannabis flower is placed and heat is applied. Once the vapour is released, it can be inhaled through the mouthpiece of the vaporiser.

Depending on the type of dry herb vaporiser, these temperatures are applied via either convection or conduction:

Convection vaporisers work in a similar way to a fan oven, circulating heat around the cannabis flower to raise the temperature in the chamber. As the chamber heats up, the cannabis begins to release a cannabinoid-rich vapour.

Conduction vaporisers apply heat from the heating element directly to the plant matter inside the chamber. This can be compared to the way food is heated up in a frying pan. Compared to convection vaporisers, conduction models tend to disperse heat less evenly.

Vaporisation vs Combustion

Combustion is the scientific name of the burning process - i.e., the chemical reaction between a fuel (in this case, cannabis) and an oxidant (usually oxygen). 

Combustion of cannabis and tobacco can involve temperatures of up to 900°C - far above those needed to release valuable cannabinoids and terpenes from the plant matter. So, is vaporisation the same as combustion? Well, put simply - no! 

What's the difference between burning and vaporising?

In contrast to the extremely high temperatures seen in combustion, vaporising involves much lower temperatures. In fact, the majority of dry herb vaporisers will have a maximum temperature setting of around 200-220°C. While you might think that this would make vaporising a less effective consumption method compared to smoking, the opposite may actually be true.

Evidence suggests that many active compounds found in cannabis may begin to degrade when exposed to the high temperatures caused by combustion. This could mean that a significant proportion of the cannabinoids and terpenes in your cannabis may be destroyed before they enter the body.

Cannabis vaping temperatures

Cannabinoids - the most significant medicinal compounds found in cannabis - have varying boiling points; however, almost all of these boiling points sit in a range of between around 50°C and 200°C, well within the range of most dry herb vaporisers. For example, CBD is believed to reach boiling point at around 180°C while THC begins to vaporise at around 157°C.

Applying lower temperatures could help to preserve the cannabinoids and terpenes in your cannabis flower allowing you to get the most out of each dose. 

Is vaping dry herbs better than smoking for your lungs?

While there is some evidence to suggest that cannabis smoke is not as harmful as tobacco smoke, inhaling any kind of smoke can pose significant health risks. Combustion of plant materials is known to release a number of toxic compounds, including carcinogens, that can have a negative impact various aspects of your health. 

Avoiding combustion through vaporisation prevents the release of many of these harmful compounds. Furthermore, the vapour released by a dry herb vaporiser tends to be cooler and less harsh than cannabis smoke. This could help to prevent irritation in the throat and lungs during and after consumption. 

What is the downside of a dry herb vape?

Of course, there is a downside to dry herb vaporisers - though compared to their benefits, they are minimal. Given the various components involved, vaporisers require some maintenance, including cleaning, and potential part replacements. Depending on the type of vaporiser, you may be required to dismantle and clean each part separately. However, you should always be given guidance on the appropriate maintenance requirements for your device. 

Are dry herb vaporisers legal in the UK?

Like e-cigarettes and some other vaping products, dry herb vaporisers are legal in the UK. In recent years, a number of dry herb vaporisers have even been approved for medicinal use. This provides patients with peace of mind over the quality and safety of the products they use to medicate. Some examples include Storz-Bickel’s Mighty Medic, Mighty+ Medic and Volcano vaporisers; however, other high-quality options are available

Omura Flower Vaporisers at Releaf

Medical cannabis patients with a Releaf+ subscription all receive a Welcome Box containing an Omura Flower Vaporiser. These high-quality dry herb vaporisers take a unique approach to vaping, utilising “flower sticks” that are inserted into the device and heated to release a cannabinoid-rich vapour. This innovative design makes the Omura vaporiser simple to use and easy to maintain, as it never needs cleaning.

What is the difference between cannabis oil and wax pens and dry herb vaporisers?

As mentioned above, like oil and wax pens or e-liquid vapes, dry herb vaporisers involve gently heating an ingredient to cause vaporisation. However, dry herb vaporisers offer the ability to consume cannabis in its purest form. High-quality cannabis flower (such as that prescribed by medical clinics) shouldn’t contain any additives or potentially harmful products. 

Unfortunately, the same cannot necessarily be said for products like oil pens and wax pens. As dry herb vaporisers are the only inhalation method recommended by clinicians in the UK (doctors will never prescribe cannabis to be smoked), they are considered the best option for vaporising cannabis. 

Final Thoughts

Dry herb vaporisers are becoming increasingly common in the UK, with patients and recreational consumers alike attracted to their convenience and improved health credentials. Not only could dry herb vaporisers help you to get more out of your cannabis flower, they could also make for a more enjoyable and safer experience, and improve dosing at the same time!

It is important to seek medical advice before starting any new treatments. The patient advisors at Releaf are available to provide expert advice and support. Alternatively, click here to book a consultation with one of our specialist doctors.

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Emily, an accomplished content writer with a specialisation in cannabis and alternative health, leverages her five years in the sector to enhance education and diminish stigma around medicinal cannabis use.

Our articles are written by experts and reviewed by medical professionals or compliance specialists. Adhering to stringent sourcing guidelines, we reference peer-reviewed studies and scholarly research. View our editorial policy.

Further reading

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