What types of damper seals are available and when should I use each?

Damper seals include compression-type edge seals (EPDM or silicone rubber bulb), stainless steel side seals (flexible metal for high-temperature), and inflatable seals (for bubble-tight shutoff in cleanrooms). EPDM edge seals are standard for most HVAC applications up to 200°F with leakage rates of 3–10 CFM/ft² at 1 in. w.g. per AMCA 511 Class 1A, while silicone seals handle up to 350°F or applications where EPDM off-gassing is a concern. For smoke control dampers, stainless steel jamb seals with Class I ratings (<4 CFM/ft² at 4 in. w.g.) are required per UL 555S, and cold-climate outdoor air dampers need blade edge seals with thermal-break frames to prevent ice formation and actuator overload during freezing conditions.