8" x 4" BA-CDDW Compression Duct Door for Double-Wall Duct
The 8" x 4" BA-CDDW Compression Duct Door for Double-Wall Duct provides an insulated access point for double-wall and insulated sheet-metal ductwork. Designed with an increased steel bolt length to span up to a 1" maximum duct wall/insulation thickness, it clamps inner and outer 20-gauge plates around polyfoam insulation and a closed-cell neoprene gasket.
Tested to 20 inches static pressure with minimal leakage, it is available for flat double-wall ducts and in pre-curved versions for round ducts. Depending on the selected door size, the round model fits duct diameters ranging from 4 to 60 inches.
Why Choose 8" x 4" BA-CDDW Compression Duct Door for Double-Wall Duct?
Designed for 1" Insulated Duct-wall Thickness: Increased bolt length specifically accommodates double-wall and insulated duct builds up to 1" thick.
Tested to 20" S.P. Seal: Tested to hold up to 20" static pressure (S.P.) with minimal air leakage on high-pressure systems.
Flat and Round Duct Configurations: Choose a flat model for flat double-wall ductwork or a pre-curved model for round double-wall ductwork. For the round configuration, the inner plate is manufactured 2 inches smaller in diameter than the outer plate.
Durable Metal Construction: The sandwich-style assembly uses formed 20-gauge plates, with galvanized steel supplied for the 8 × 4 model and galvanized, stainless steel, or aluminum options available for the 10 × 6 and 16 × 12 sizes.
Reusable Compression Hardware: Steel bolts, compression springs, and polypropylene knobs allow the plates to be loosened for access and tightened again against the neoprene gasket.
Dual Thermal Barrier: Combines double 20-gauge metal plates, an internal polyfoam insulation core, and a closed-cell neoprene gasket to minimize condensation and air bypass.
Need help confirming whether the BA-CDDW suits your project? Contact our product specialists to confirm the door size, flat or round configuration, duct diameter, total wall thickness, and available material before ordering.
What Are the Key Product Specifications for the BA-CDDW?
Door Size: 8" x 4"
Construction: Formed 20-gauge inner and outer metal plates
Insulation: Polyfoam insulation
Closure Hardware: Steel bolts, steel compression springs, and polypropylene knobs with metal inserts
Gasket: Closed-cell neoprene
Duct Type: Flat or round double-wall ductwork
Maximum Duct-Wall Thickness: 1"
Pressure Test: Tested to 20" static pressure with minimal leakage
Included Installation Aid: Self-adhesive cutout template
Round-Duct Compatibility: Diameter range depends on the selected door size:
8" × 4": 6"28" duct diameter
10" × 6": 5"30" duct diameter
16" × 12": 12"60" duct diameter
What Comes Standard and What Can Be Configured?
Every BA-CDDW ships with the following as standard:
Formed 20-gauge inner and outer metal plates
Polyfoam insulation
Steel bolts with increased length for double-wall duct assemblies
Steel compression springs
Polypropylene knobs with metal inserts
Closed-cell neoprene gasket
Self-adhesive cutout template
The following can be specified at the time of order:
Duct Configuration: Flat double-wall duct or pre-curved round double-wall duct
Material:
8" × 4": Galvanized steel
10" × 6" and 16" × 12": Galvanized steel, stainless steel, or aluminum
Round-Duct Diameter: Round models must be ordered for the applicable duct diameter and selected within the documented size range.
Need a different size, material, or configuration? While the BA-CDDW is offered in a standard configuration, our team will help you explore custom access solutions for just about any specialized project requirement.
What Do You Need to Know About Installation Requirements?
Fitting the Door
The BA-CDDW installs through a cut opening in the duct wall. Its inner and outer plates are drawn together across the insulated assembly using steel bolts, compression springs, and hand-tightened polypropylene knobs.
Confirm the opening size and the duct wall thickness before ordering, so the bolt length suits the duct.
Installation Notes
Verify that the total duct wall thickness does not exceed 1".
Use the included self-adhesive template to establish the cutout.
Position the inner and outer plate assemblies on opposite sides of the duct wall.
Tighten the polypropylene knobs so the steel bolts and compression springs draw the plates together.
Who Specifies BA-CDDW and Where Is It Used?
The BA-CDDW is typically specified by mechanical engineers, HVAC contractors, and sheet metal fabricators who need sealed access on a pressurized double-wall or insulated duct.
Common applications include:
Commercial HVAC - insulated duct access
Institutional mechanical systems - double-wall duct service
Healthcare facilities - insulated duct access
Industrial air systems - double-wall duct service
Looking to get more out of your repeat access door orders? Join Pro Club for priority contractor pricing, dedicated support, extended returns, and exclusive tools to streamline your ordering process.
Frequently Asked Questions About Double-Wall Compression Duct Doors
How is the BA-CDDW different from the single-wall version?
It uses an increased bolt length, so the door can encompass the full thickness of a double-wall or insulated duct, whereas a single-wall door would not span the duct.
What pressure is it rated for?
The BA-CDDW is pressure tested to 20" S.P. with minimal leakage.
Does it work on insulated ducts?
Yes. It is designed for double-wall or insulated duct construction with a maximum total duct wall thickness of one inch.
Can it be resealed after opening?
Yes. The knob, bolt, and spring assembly can be loosened for access and tightened again afterward. The closed-cell neoprene gasket remains part of the sealing assembly
Is it available in other materials?
Yes. Specialty metals such as stainless steel and aluminum are available for demanding or corrosive environments in addition to standard galvanized steel.
Get Sealed Double-Wall Duct Access for Your Project
When double-wall or insulated ductwork needs routine service access, standard duct doors may not span the full wall thickness or reseal effectively after opening. The BA-CDDW addresses that challenge with extended bolts for duct walls up to 1" thick, insulated sandwich construction, and a closed-cell neoprene gasket.
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