The last fan we’re about to test comes from Zalman. It is a recently released ZM-F4 model. It is packed in a plastic blister wrap with a paper insert.
The Zalman ZM-F4 is shipped together with four silicone pins and a resistor cable.
The fan is manufactured in China. It costs $5 and has a 1-year warranty.
Unlike the other models, the Zalman ZM-F4 measures 135x135x25 mm although it doesn’t look smaller than the others.
The 11-blade impeller is 128 mm in diameter, which is almost as large as impellers of full-size 140mm fans. The blades are curved aggressively and have sharp edges and thick ends.
The nominal fan rotation speed is 1300 RPM, but it can be lowered to 900 RPM using the enclosed resistor. The air flow and static pressure aren’t mentioned among the fan specifications, and the declared noise level shouldn’t exceed 26 and 18 dBA for each operational mode respectively.
The stator with 47 mm diameter (the largest of all tested fans) has a sticker with the fan model, voltage and current as well as the bearing type:
The Zalman ZM-F4 runs on an improved sleeve bearing with a specified service life of 50,000 hours or 5.7 years of continuous operation. The maximum power consumption of the fan is not expected to be higher than 3.36 watts. The cable is 390 mm long.