E3D are out of stock on the 24 volt fan for the E3D Hemera but have the 24 volt 40x40x10mm fan comes as standard with the Titan Aero in stock, is there any difference in these 2 fans? Im using an old 40 x10 fan that I had spare, its working fine so far but does feel like theres less air coming out of the heatbreak. A 40x40x20 will not fit as I have the BL Touch in front of the fan. The only specs I have for the old fan im using are... Amp .06 RPM 7500 CSM 5.22
I don't have a specific recommendation for you other than to say that any 40x40x10 24v will work, though I know there are variations that trade off RPMs for reduced noise. I replaced my stock fan with a 40x40x20 for reduced noise and increased airflow, and I've been very happy. Should be just a matter of remixing your mount. And yes, I'm aware that I need to complete my cable management.