@maximry
Your argument is invalid.
That Sunon fan model I mentioned, actually has a slightly higher airflow than that Delta model.
It does not matter which brand cooling fan you use.
The specs (airflow, supply voltage, pwm control or not, etc. ) only matter.
Cooling fans are bulk stuff.
My arguments are absolutely valid for Delta. I wrote especially about Delta fans. The Delta company have the only one model with 140 mm and 12V features - PFM1412DEB7V . Z1Pro factory doesn't glue any stickers on their fans. That's why some people have this problem.