The NA-FH1 is a PWM fan hub with 8 standard Molex fan ports. To know how many fans can be powered at once, one must consider the total current consumption of the connected fans.
To calculate the total current consumption, simply add up the amperage of all fans (see examples below). Note that the total maximum current will differ depending on whether the NA-FH1 is powered through its 4-pin PWM input (e.g. from a PC motherboard fan header) or through its S-ATA input.
Powering the NA-FH1 via 4-pin PWM (e.g. from a motherboard fan header):
When using only the 4-pin PWM input, 2A total can be supplied at maximum. However, many motherboard headers can only supply 1A, which would also limit the NA-FH1 to 1A. Please check your motherboard manual for the maximum current of the fan header and make sure not to exceed it.
As an example, we will now calculate the number of NF-A12x25 PWM fans that can be connected to the NA-FH1. The maximum current drawn by this model is 0.14A. Dividing the 1A motherboard maximum by this value (1/0.14 = 7.14), we can conclude that 7 of these fans can be safely connected to the hub.
If the NA-FH1 receives power through its 4-pin PWM input from a source that is not limited to 1A (e.g. a power supply or a motherboard fan header that’s rated at 2A), it will support up to 2A total, so up to 0.25A per output port.
Powering the NA-FH1 via S-ATA:
When using the S-ATA input of the NA-FH1 (optionally with the 4-pin PWM input for speed control), a total of 4.5A can be supplied.
As our second example, we will calculate the number of NF-A14 industrialPPC-3000 PWM fans that can be connected. This is our fan model with the highest maximum current, namely 0.55A. Dividing the 4.5A by this value shows that 8 fans can safely be connected, with headroom to spare.
Attention!
Please note that the NA-FH1 not only has limits for the total current drawn by all fans connected, but also regarding the current per fan header: 2A with 4-pin power (24W max. total output) and 3A with S-ATA power (54W max. total output).
Please make sure not to exceed these values when connecting several fans to one fan header via splitter cables!