Axial fans: Ziehl-Abegg
Ziehl-Abegg is an upcoming brand in the flower bulb sector. The fans are equiped with an infinitely variable DC motor. The motor is adjustable with a potentiometer or a computer. Furthermore the fan is designed with a square mounting plate.
A lot of attention is paid to the design of the blades. As a result of the bended shape and the sharpened blade profile the blades have become much more streamlined. This makes Ziehl-Abegg fans silent.
Axial Fans: Klima
Klima is a well-known brand with more than 50 different types of fans. With blade diameters varying from 630 mm to 1100 mm there is a Klima fan available for almost every situation. All the fans are equiped with an AC motor except for one type. A disadvantage of an AC motor is that it is not adjustable. To realise this a power inverter should be added.
In 2010 Klima added a fan with a DC motor to their assortment. This fan contains the same characteristic housing and blades. The AC motor has been replaced by a DC motor.
Centrifugal fans: Thermo Air
The use of centrifugal fans is reducing. Its effectivity is limited and the fan is relatively expensive. An advantage of this type is that the fan is silent. As a result of the introduction of the silent Ziehl-Abegg the centrifugal fan shall probably disappear eventually.