More embarrassed behind quiet office equipment (8)
I believe the answer is:
shredder
'office equipment' is the definition.
(I've seen this before)
'more embarrassed behind quiet' is the wordplay.
'more embarrassed' becomes 'redder' (someone may go red from embarrassment).
'behind' is a charade indicator (letters next to each other).
'quiet' becomes 'sh' ('sh' is used to tell someone to be quiet).
'redder' after 'sh' is 'SHREDDER'.
(Other definitions for shredder that I've seen before include "destroyer of confidential material" , "Red herds (anag.)" , "one destroys paper" , "Paper-cutter" , "Evidence destroyer" .)