What Is a Butterfly Collar Damper? Specs and How to Specify One
A butterfly collar damper uses a single flat disc pivoting on a central shaft, built into a round duct collar for compact airflow regulation at branch takeoffs and diffuser necks. Specs, applications, and how to specify one.
A butterfly collar damper is a compact airflow regulation device built into a round duct collar, using a single flat disc that pivots on a central shaft to open or close the passage. Goodwind manufactures the Butterfly Collar Damper (model GT-BCD) in aluminum, galvanized steel, or stainless steel, sized to the duct dimensions, as part of its wider damper range designed to minimize turbulence and noise.
Butterfly Collar Damper Specifications
| Spec | Detail |
|---|---|
| Model | GT-BCD |
| Material | Aluminum, galvanized steel, or stainless steel |
| Size | Customizable to duct dimensions |
| Design | Single flat disc, pivoting on a central shaft, built into a round collar |
| Applications | Round duct branch takeoffs, diffuser and grille neck connections |
Butterfly Collar Damper vs. Volume Control Damper
Both regulate airflow rather than shutting off for life-safety reasons, but they suit different locations. A volume control damper typically uses multiple blades across a larger rectangular or round duct section. A butterfly collar damper is a single-disc design built directly into a round collar, making it the more compact, economical choice for smaller round duct connections — branch takeoffs, or the neck connection feeding an individual diffuser or grille.
How to Specify a Butterfly Collar Damper
For MEP Consultants at the Design Stage
Matching the Damper to the Connection Point
Specify a butterfly collar damper at individual branch takeoffs or terminal neck connections where balancing airflow to a single outlet is the goal, rather than at a main duct trunk where a multi-blade damper suits the larger cross-section better.
Confirming Access for Adjustment
Since these dampers are often installed above a ceiling at a diffuser or grille neck, confirm there's practical access for balancing adjustment after installation, particularly in tight ceiling voids.
For Contractors at Procurement Stage
Confirming Collar Diameter Before Ordering
Confirm the exact round duct diameter against the drawing before ordering, since the damper is built to the specified collar size rather than stocked in fixed dimensions.
Verifying Material Against Application
Match material to the application — stainless steel for corrosive or high-moisture airstreams, aluminum or galvanized steel for standard comfort HVAC branches.
FAQ
What is a butterfly collar damper used for?
It's used for airflow balancing at round duct branch takeoffs and individual diffuser or grille neck connections.
How is it different from a volume control damper?
A volume control damper typically uses multiple blades across a larger duct section. A butterfly collar damper is a single-disc design built into a compact round collar for smaller connections.
Can it be adjusted after installation?
Yes, but confirm there's practical access to the damper for balancing, especially when installed above a ceiling.
What materials are available?
Aluminum, galvanized steel, or stainless steel, sized to the duct dimensions.
Balancing airflow at individual branch takeoffs? Contact Goodwind for technical input, or see our industrial control damper guide for heavier-duty process applications.