Love the hot air re-use. If you want to quiet it down significantly without breaking the bank, check out Fruition Design's adapters and a 8" inline fan. Have installed them on all my rigs and they work wonders for keeping the noise down significantly vs. the stock Bitmain fans. I linked to Fruition and the inline fan I use on mine. Have been running for months on end w/out any issues.

https://fruitiondesignsllc.com/

https://www.amazon.com/gp/product/B0BTY1D14C/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1