Due to hotend design there is problem, that hotend fan can take air to cool down from bad places where is hot air, like bellow from around heatblok and heatbed and that can lead to melt filament too soon before heatblok and cause clog. So to prevent this heat creep I designed a little fan duct to prevent that. Its made to take air directly from the side of hotend housing. Its made simply to just screw directly to part cooling fan, than you can assemble front hotend housing as normal. Hope it will help you.
Print from PETG or ABS for better heat resistance.
There is also model for P1P/P1S in my published models: https://makerworld.com/de/models/91769#profileId-98170