Furnish and install round balancing dampers manufactured by Johnson Controls.
- Damper shrouds are to be constructed of formed 20-gauge G90 galvanized sheet steel or 304 stainless steel, mechanically joined.
- Damper blades are to be constructed with single-piece galvanized steel or 304 stainless steel based on shroud material.
- Damper performance shall not require tight shutoff. The damper must be rated to operate over a temperature range of -20°F to 200°F (-29°C to 93°C) or 20°F to 350°F (-29°C to 177°C), to be determined by the material.
- Damper sizing shall be by the designer in accordance with accepted industry practices to insure proper system performance.