The selection criteria depends on the calculation mode

**Mode: Cooling, Heating**

IN MANIFOLDS

The software selects the IN manifolds with minimum external diameter such that:

velocity inside manifolds <= velocity inside tube

OUT MANIFOLDS

They are selected equal to IN manifolds

**Mode: Condensing**

IN MANIFOLDS

The software selects the IN manifolds with minimum external diameter such that:

velocity (gas) inside manifolds <= velocity inside tube (gas)

OUT MANIFOLDS

The software selects the OUT manifolds with previous external diameter of the IN MANIFOLDS

**Mode: Direct Expansion**

IN MANIFOLDS

Nothing

OUT MANIFOLDS

velocity (gas) inside manifolds <= velocity inside tube (gas)

**Mode: Steam**

IN MANIFOLDS

The software selects the IN manifolds with minimum external diameter such that:

velocity (gas) inside manifolds <= velocity inside tube (gas)

OUT MANIFOLDS

The software selects the OUT manifolds with previous external diameter of the IN MANIFOLDS

**Mode: Pump evaporator**

IN MANIFOLDS

The software selects the IN manifolds with minimum external diameter such that:

velocity (liquid) inside manifolds <= velocity inside tube (liquid)

OUT MANIFOLDS

They are selected equal to IN manifolds