Heat pump cascade with a common buffer tank: basic operating principle

In installations with two or more heat pumps, a common buffer can act as a thermal and hydraulic hub.

Common charging

The units add power according to the load and charge the same tank.

Hydraulic decoupling

The secondary circuit can operate with a different total flow rate than the primary.

Cascade control

Proper lead/lag, rotation, and setpoint logic is required to avoid unnecessary simultaneous operation of all units.