The system is cheaper because there is no separate expansion vessel, the pipes are thinner and there is no need for a safety valve.
Peace of mind thanks to the system's safety mode which activates in abnormal conditions; protection against frost and extreme heat.
No need for a discharge ring which consumes lots of energy (fan, circulation pump).
The system is simpler and faster to install.
Protection against heat-transport fluid deterioration.
More efficient than pressurised systems.
Pressurised systems need to be "undersized" in order to prevent any risk of overheating.
The circuit is fully sealed and closed with no static pressure.