To officially play 4k UHD content you will need Windows 10, an approved UHD Blu-ray drive, HDMI 2.1 card (not absolutely needed for 4k, but needed for 8k), approved playback software (some drives will include it, but not all), and a complete HDCP 2.2 end-to-end encryption chain from the PC to your display device.
We have not yet seen any HDMI 2.1 cards which are low enough power to be passively cooled. That said, there are plenty of cards that are effectively silent (the 3060 Ti is in the ~35db range at full load, and 0db at idle as the fans can shut off). Decoding 4k UHD video is not something that will fully stress these cards and as such they will not hit 35db trying to do it.
You can look to get a 3060 non-TI for this duty as well as it will be more than capable, but you will hamper the ability to run any kind of 4k gaming if you do (it is stretching it with current gen games to do 4k with a 3060 Ti already).
I would suggest a card that has 2xHDMI outputs. I say this because many audio recievers/preprocessor are still not fully HDMI 2.1 compliant, and you may need to use one of the outputs to connect to the audio receiver and the other go directly into your TV/display device in order to have the best picture possible.