It is used when the flow rates of the system are higher than those achievable by the boiler and its sizing must take into account the average speed of the fluid both inside the main body and on the connection attachment.
Exchanger + Dirt separator
Balancer + Circolatore
Balancer + Dirt separator + Circulator
The configurations in the external box can be combined with the same plate heat exchanger kits provided for indoor installations with 2 separate kits for connection to the right or to the left.
Exchangers + Circulator