Is it possible to just buy some replacement fans, ofc I will get the same sized fans, not bigger or smaller and install them on my GPUs? Would that interfere in any way with the card?
It is possible, but if you want replacement fans then, according to Vann, you can get them directly from sapphire for not that high price:
Replacements are $12.50 each including shipping from Sapphire and they are super easy to replace.
Isn't sapphire only selling led versions, that slightly different (0.35 vs 0.42 current, different noise floor). Only place I've found CF1015H12D selling is single lot on ali, that not available anymore, and it was $26.5 per fan. So, can you tell where are you getting such cheap replacements from sapphire directly?
The replacement black fans are available from Sapphire. Email Sapphire at
tech@althonmicro.com. The LED fans are for retail stores.
Also, more generally good advice it that thread -
https://bitcointalk.org/index.php?topic=2949541.0;all