According to one embodiment, a hazard detector may include a back plate and a front casing coupled to the back plate to define a housing having an interior region and an opening through which air flows into the interior region. A circuit board may be coupled to the back plate and have a plurality of components mounted thereon. A smoke chamber may be mid-mounted on the circuit board, mid-mounting being characterized in the smoke chamber extending through a hole formed in the circuit board such that a top surface of the smoke chamber is positioned above a top surface of the circuit board and a bottom surface of the smoke chamber is positioned below a bottom surface of the circuit board, whereby an interior region of the smoke chamber is accessible to smoke from both the top and bottom surfaces of the circuit board.