Infra-red heat that is produced by the burner must be directed into the space to be heated. High intensity units are AGA and CGA design certified to be mounted horizontally or at an angle up to 30° These attitudes plus a standard, shallow, straight sided reflector insures that infra-red output is not directed to the walls. The standard reflector reduces dispersion to the sides and produces a conical spread of approximately 90°. A parabolic reflector extension may be added to the standard reflector to produce a deep (concentrating) reflector. The extension is used for concentrating infra-red energy usually for spot heating or higher mounting height applications.