If you want an elegant solution to the problem, consider getting yourself an IKEA Billy bookshelf ... you just slide the printer inside and shut the door. Its thermal and noise isolating ...
Assuming you need to use the BILLY extension pieces to make your unit go to the ceiling, and you want them to be closed shelves, your only option for a door from IKEA is the single version of the ...
The shelves were sanded, primed, painted and installed with extenders, skirting and molding. The doors, made by IKEA to fit Billy bookcases, are called Oxberg doors.