1993 Buick Roadmaster Owner's Manual - Page 134

. . 'Your Buick may have Comfort Control. System. this . . , . . . Your Bui&'s flow-through ventilation system supplies outside airinfo the vehicle whenit is,moving.When the heater or air c.onditioningfan is running, outside.air will also enter the-vehicle... , . Fan Speeds: The fan-control is used to select the speed you' want the blbwer to contrdl the:& flow. B/L(Bi-level): This setting is designed use on s m y days'whexe the for air is only moderately warm or.-c6c?l. n days like these, O