As explained under Characteristics the same principle of folding and soldering is always used to make the pads, but they are produced with different flute sizes. The smaller the flutes, the larger the surface of interchange between liquid/air. This surface area, expressed in m2 of surface area per m3 of pad, varies between 100 (model RC-100) and 280 (model RS and SS-280).

The flutes, which are always straight, can be perpendicular (type R) or oblique (type S) in relation to the entry and exit of the air.

The pads with perpendicular flutes, type R, are used as fill in cooling towers and the efficiency of the pad is proportional to the m2 of surface area per m3 of pad. The models with the smaller surface areas (model RC-100 and RA-160) are especially suited to handle dirty water or water with some solid fragments.

The pads with oblique flutes are used to capture the drops of liquid expelled from the cooling tower by the air (drift eliminators) and for units with horizontal circulation of air (Evaporative conditioners, humidifying sections of air conditioning units, etc.).

The pads, type RF-240, are different from the rest of the types because the flutes are parallel to the flow of the air and perpendicular to the flow of the water. This type of pad is made especially for the use in cooling towers with cross-flow and is also used in the F and SF types Humibat® manufactured by Control y Ventilación.