Bradford White DS140S Installation And Operating Instruction Manual page 13

Installation (Venting) continued-
(h) underneath a verandah, porch or deck, unless:
(i) the verandah, porch or deck is fully open on a minimum of two
sides beneath the floor, and
(ii) the distance between the top of the vent-air intake termination and
the underside of the verandah, porch or deck is greater than 12 in.
(30.5 cm).
Figure 4
13