Accurate vaporizers contain an electric element for heating, which are provided with thermostat temperature control. Good quality models may cost you very high.
Based on the way vaporizers heat the substance, they are broadly classified as:

1. by convention
2. by thermal conduction
3. by thermal radiation

In convention method, heating element is not brought in contact with the substance. Instead, we pass the hot air through it, heat it quickly, thus releasing the active ingredients. This technique of heating allows more release of active ingredients as compared to conduction heating.

• In many convention vaporizers, a tube is used which user uses to inhale the vapors.
• Convention vaporizers are further classified as :

1. Forced air types- these types blow air from the heating herbs or elements.

2. Passive types- in these types air is inhaled by the user without the use of pump or fan.
In thermal conduction, first the substance is positioned on the metal plate which is then heated so that its active ingredients are released. These types of vaporizers appeared first in the market and are still produced.

In thermal radiation, the substance is exposed to intense light. The radiant energy is absorbed by the substance which leads to increase in its temperature.