Hello thanks for choosing Dell. It should be hot swappable. 

Let us know if you have any further questions. Wish you a good one.

Is there any written Dell document to confirm that they are hot swappable (or hutplug) ? I cannot find such information anywhere. 

Hi,

i would not recommend hot swap because you have to open the chassis:

https://dell.to/3N8BLPv

Regards Martin

As i wrote it is a sales problem so we do not plan to swap any fans. We are looking for confirmation, that the fans can be hotplugged/hotswapped.

Hello marcin.rabiniak,

Unfortunately the fans cannot be hot swap.

Hot swap components will have an orange tab or some other piece. 

Cold swap components will have a blue tab or piece.

Features of the cooling fans:

*Cooling fans are labeled FAN 1 through FAN 7.

*All cooling fans are cold swappable.

*The cooling fan labels are printed on the fan cage.

Hello marcin.rabiniak

My sincere apology for misinformation. I misread your inquiry. I would have and should have presented the same link that Martin also provided previously, for the grounds of my assertion. https://dell.to/44aLFWH

'Dell EMC PowerEdge R450 Installation and Service Manual'