A residential sidewall sprinkler for mounting to one of two substantially parallel vertical wall surfaces extending between a substantially flat ceiling and a floor to define a coverage area for the sprinkler, the sprinkler comprising: a body having an inlet and an outlet defining therebetween a passageway defining a K-factor of about 86.4LPM/bar1⁄2 (about 6 GPM/psa1⁄2) and a longitudinal axis (A-A), the body having a proximal end for coupling the sprinkler to a fluid supply line, the body having a distal end opposite the proximal end; a deflector assembly having a proximal portion and a distal portion, the deflector assembly being coupled to the distal end of the body, the deflector assembly including: a face portion distally spaced from the outlet of the body and substantially orthogonal to a first plane and a second plane intersecting along the longitudinal axis (A-A), the face portion including at least one opening, the deflector assembly further including: a first canopy and a second canopy disposed about the first plane to define a channel therebetween in communication with the opening, at least one of the first and second canopies (24,26), wherein the first canopy provides an upper canopy, the second canopy provides a lower canopy, defining a horizontal component to fluid passing between the canopies (24,26) such that the deflector assembly provides at least one of a consistent horizontal and vertical fluid distribution pattern for at least one of a substantially constant fluid pressure and substantially constant fluid flow rate provided to the inlet over a range of ceiling-to-canopy distance between the ceiling and the upper canopy, the ceiling-to-canopy distance ranging between 101.6mm to about 304.8mm (four to about twelve inches), wherein the upper canopy defines a shorter distance than the lower canopy relative to the first plane about which the upper and lower canopies (24,26) are disposed, characterised in that the face portion includes a first plurality of undulating portions (21a,21b) integral with the upper canopy and a second plurality of undulations (21a,21b) integral with the lower canopy such that each of the upper and lower canopies (24,26) extends proximally and distally of the face portion. a body having an inlet and an outlet defining therebetween a passageway defining a K-factor of about 86.4LPM/bar1⁄2 (about 6 GPM/psa1⁄2) and a longitudinal axis (A-A), the body having a proximal end for coupling the sprinkler to a fluid supply line, the body having a distal end opposite the proximal end; a deflector assembly having a proximal portion and a distal portion, the deflector assembly being coupled to the distal end of the body, the deflector assembly including: a face portion distally spaced from the outlet of the body and substantially orthogonal to a first plane and a second plane intersecting along the longitudinal axis (A-A), the face portion including at least one opening, the deflector assembly further including: a first canopy and a second canopy disposed about the first plane to define a channel therebetween in communication with the opening, at least one of the first and second canopies (24,26), wherein the first canopy provides an upper canopy, the second canopy provides a lower canopy, defining a horizontal component to fluid passing between the canopies (24,26) such that the deflector assembly provides at least one of a consistent horizontal and vertical fluid distribution pattern for at least one of a substantially constant fluid pressure and substantially constant fluid flow rate provided to the inlet over a range of ceiling-to-canopy distance between the ceiling and the upper canopy, the ceiling-to-canopy distance ranging between 101.6mm to about 304.8mm (four to about twelve inches), wherein the upper canopy defines a shorter distance than the lower canopy relative to the first plane about which the upper and lower canopies (24,26) are disposed, characterised in that the face portion includes a first plurality of undulating portions (21a,21b) integral with the upper canopy and a second plurality of undulations (21a,21b) integral with the lower canopy such that each of the upper and lower canopies (24,26) extends proximally and distally of the face portion.