The dimension of the liquid receiver has to take into account the respective volume(s) of – the condenser(s) – Vcond – the evaporator(s) – Vevap – and the liquid line between the receiver and the expansion valve(s) – VLL. An easy formula enables to calculate the dimension of the receiver: V1 = Vcond x 0.2 + Vevap x 0.8 + VLL In order to avoid an excessive increase in pressure in the receiver, due to the liquid dilatation, it is essential to provide for an additional safety volume (25% to 30% of total refrigerant volume). Then, the volume of the receiver to select will be at least: Vres = V1 x 1.25.