If you install the apparatus in a built-in installation,
such as a bookcase or rack, ensure that there is
adequate ventilation. Leave 20 cm (8") of free space at the top and sides and
10 cm (4") at the rear. The rear edge of the shelf or
board above the apparatus shall be set 10 cm (4")
away from the rear panel or wall, creating a flue-like
gap for warm air to escape.