Storage temperature for the Amp is -4°F to 122°F. The Amp needs airflow to stay cool. If the box is not ventilated, there is a risk of the Amp overheating especially if it’s in a box with two other devices.

Thanks for the info. Is there a better recommended solution? I don’t want the amp to be in the rack because HDMI length would exceed 50 feet (i think TV location is around 120 ft from rack).

I’m not following exactly what this box looks like, how big it is, but you  could just mount the amp directly to the wall.  Depending on how big your TV is and what sort of mount you use, there could be plenty or room for the Amp and your other devices.

Not exactly the same situation, but I have a lot of equipment in the closet behind my TV.  It does get rather hot in there, but I resolved by installed a temperature controlled fan that will vent air into the attic space above when it get’s too hot.

Planning on using this box: https://www.snapav.com/shop/en/snapav/boxes/strong-trade%3B-versabox%E2%84%A2-pro-%7C-recessed-flat-panel-solution---14-x-14--sm-rbx-pro-14-blk

Unfortunately there are alot of samsung frame TVs so there is no way to mount anything external of box. I will investigate a small fan that can mount inside this box to exhaust hot air, thanks!

Will try to use something like this to exhaust the hot air with conduit running to recessed box, what do you think?

https://www.amazon.com/AC-Infinity-CLOUDLINE-T6-Temperature/dp/B074XBXFPD/ref=sxin_9_pa_sp_search_thematic_sspa?cv_ct_cx=duct+booster+fan&dchild=1&keywords=duct+booster+fan&pd_rd_i=B074XBXFPD&pd_rd_r=732fe83c-cbe6-45fe-8d39-103cb88ba5b9&pd_rd_w=7Gmtz&pd_rd_wg=lTVwN&pf_rd_p=9d5c7dec-ad7e-424f-9792-7751bf0f49a3&pf_rd_r=HBJ1AG11NN5DC0SXSXW6&qid=1624126490&sr=1-2-a73d1c8c-2fd2-4f19-aa41-2df022bcb241-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUE3MDFXRlU4UlRMUlMmZW5jcnlwdGVkSWQ9QTAyMDg4MTcxNVk2OVdCMlRYQVRMJmVuY3J5cHRlZEFkSWQ9QTA0Njc3ODI4Sk1WWkJXTEVFVUEmd2lkZ2V0TmFtZT1zcF9zZWFyY2hfdGhlbWF0aWMmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl