YONGFAN HVAC - Premium Header
Engineered HVAC & Industrial Air Systems
Product Finder Technical Support Download Center
YONGFAN HVACYOFAN HVAC Home
Request a Quote
Contact UsGlobal sales team contacts Request a Quote (RFQ)Submit BOQ or equipment list Request Product SelectionGet customized engineering sizing
Airtight & Insulated Dampers | F-BW | YONGFAN
≤1.2 m³/(m²·h) @ 2,000 Pa · Anti-Condensation Thermal Isolation

Airtight & Insulated Dampers: F-BW Series for Cold-Air Control

Airtight insulated dampers control airflow without turning cold ductwork into a condensation point; leakage, insulation continuity and actuator choice all matter at commissioning.

YONGFAN’s F-BW Airtight & Insulated Damper Series combines insulated casing walls, internal heat-preservation barriers, and EPDM blade rubber seals to achieve verified leakage of ≤1.2 m³/(m²·h) at 2,000 Pa static differential. Available in manual handwheel (SD), electric modulating (D), and pneumatic (QD) configurations.

Leakage Rate≤1.2 m³/(m²·h)
Test Pressure2,000 Pa ΔPt
Blade SealsEPDM Elastic Gasket
Body Length≥210 mm (180–500 custom)
Select an Insulated Damper F-BW Comparison Matrix
YONGFAN motorized airtight ventilation damper
F-BW Insulated Series Thermal Break Casing · EPDM Blade Seals · ≤1.2 m³/(m²·h) @ 2,000 Pa
01 / Thermal Boundary Risks

Condensation and Leakage Usually Appear After the Duct Is Already Finished

A cold-air duct can pass its airflow test and still cause building damage once humid ambient air contacts an uninsulated damper body, creating persistent sweating and thermal bridging.

Water forms on the casing, blade shaft or actuator-side metalwork because an ordinary damper interrupts the thermal insulation protecting the rest of the duct. Condensation wets ceiling finishes, ruins mineral insulation, and triggers corrosion around fasteners.

A second failure appears when dampers are vaguely labeled “airtight” without stating a pressure basis. Leakage always depends on differential pressure, seal profile, and testing standard.

YONGFAN’s F-BW family solves both problems: insulated casing walls slow thermal transfer, while continuous EPDM rubber blade gaskets limit leakage to ≤1.2 m³/(m²·h) at 2,000 Pa.

Low temperature insulated ductwork in mechanical plant room

ANSI/AMCA Standard 500-D provides recognized laboratory methods for damper air leakage and pressure-drop testing. YONGFAN references JG/T 436-2014 for its insulated sealed damper family.

Thermal Break Insulation

Internal and external insulation measures eliminate cold bridges across the damper body, preventing surface condensation in humid environments.

Anti-Sweating Body

EPDM Elastic Blade Seals

Durable EPDM perimeter gaskets create an airtight barrier between moving opposed blades under positive and negative pressures.

EPDM Blade Gaskets

2,000 Pa Tested Leakage

Electric and pneumatic models publish leakage of ≤1.2 m³/(m²·h) at 2,000 Pa static differential for mission-critical fresh-air isolation.

≤1.2 m³/(m²·h) @ 2,000 Pa
02 / Actuation & Control

Select the F-BW Variant by How the System Will Be Operated

Manual balancing handwheels, electric modulating BMS actuators, and pneumatic control drives.
Variant 01 · Local Balancing & Adjustment F-BW-SD-DM-DK-W×H

Manual Insulated Dampers (F-BW-SD)

Constructed with hot-dip galvanized or stainless steel casing, insulated body walls, and EPDM blade seals. Features a manual handwheel providing continuous stepless adjustment of blade opening angle with a self-locking position mechanism.

Handwheel DriveSmooth worm-gear adjustment with automatic self-locking position
Zero InfrastructureIdeal for fixed commissioning balance without wiring or air lines
Insulated BodyRetains complete thermal barrier and EPDM opposed-blade sealing
Best FitFresh-air branch ducts and accessible mechanical plant rooms
Configure Manual F-BW
YONGFAN manual air-volume control damper
F-BW-SD Series Manual Handwheel · Stepless Adjustment · Self-Locking Mechanism
Variant 02 · Remote & Automatic Control F-BW-D-DM-DK-W×H · ≤1.2 m³/(m²·h) @ 2,000 Pa

Electric Insulated Dampers (F-BW-D)

Adds electric actuation supporting AC/DC 24 V or AC 220 V power supply. Designed for continuous modulating airflow control or two-position interlocked isolation connected to a central BMS or temperature controller.

Verified Low LeakageDocumented ≤1.2 m³/(m²·h) under 2,000 Pa differential pressure
Flexible PowerAC/DC 24 V or AC 220 V actuator options
Control SignalsSupports 0–10V, 4–20mA, floating, or on/off interlock commands
Best FitAutomated fresh-air economizers, AHU intakes, and cold-chain rooms
Configure Electric F-BW
YONGFAN motorized airtight damper product set
F-BW-D Series Electric Actuator · 24V / 220V · BMS Modulating Interlock
Variant 03 · Air-Powered Control Systems F-BW-QD-DM-DK-W×H · ≤1.2 m³/(m²·h) @ 2,000 Pa

Pneumatic Insulated Dampers (F-BW-QD)

Utilizes a pneumatic cylinder actuator powered by compressed instrument air. Features the same insulated body, EPDM blade seal, and ≤1.2 m³/(m²·h) at 2,000 Pa leakage rating.

Pneumatic DriveFast-acting pneumatic actuation for plants with instrument air networks
Tight SealVerified ≤1.2 m³/(m²·h) at 2,000 Pa static-pressure difference
Fail SafeConfigurable for fail-open or fail-closed spring return action
Corrosion MaterialsHot-dip galvanized sheet or 304/316L stainless steel
Configure Pneumatic F-BW
YONGFAN motorized airtight ventilation damper
F-BW-QD Series Pneumatic Actuator · Instrument Air Compatible · Fail-Safe Options
03 / Specification Matrix

Insulated Sealed Damper Comparison

Side-by-side comparison across manual, electric, and pneumatic F-BW configurations.
Variant Documented Model Control Method Leakage Boundary from YONGFAN Data Best Fit
Manual insulated sealed damper
F-BW-SD-DM-DK-W×H
 Handwheel, stepless, self-locking Insulated body + EPDM blade seals Fixed balancing and local adjustment
Electric insulated sealed damper
F-BW-D-DM-DK-W×H
 Electric actuator (24V/220V), automatic ≤1.2 m³/(m²·h) at 2,000 Pa BMS/interlocked or automatic control
Pneumatic insulated sealed damper
F-BW-QD-DM-DK-W×H
 Pneumatic actuator ≤1.2 m³/(m²·h) at 2,000 Pa Pneumatic-control systems & plant networks
04 / Procurement Protocol

What Information Is Needed for Insulated Damper Sizing?

Essential parameters to confirm before finalizing F-BW model selections, ensuring anti-condensation integrity and exact fit.
Insulated Damper Sizing Checklist

Key Sizing Parameters

Submitting your duct opening dimensions, air/ambient temperature differentials, allowable leakage criteria, and actuator preference allows our engineering team to provide certified submittal drawings.

1. Duct Opening Dimensions (W×H mm)
2. Body Length (Standard ≥210 mm / Custom 180–500 mm)
3. Supply-Air Temp & Ambient Surrounding Dew Point
4. Maximum Static Pressure Differential (ΔP Pa)
5. Drive Type: Manual (SD), Electric (D), Pneumatic (QD)
6. Electric Actuator: 24V / 220V · On/Off vs Modulating
7. Material: Hot-Dip Galvanized or 304/316L Stainless Steel
8. External Actuator Clearance & Service Space
05 / Manufacturing Standards

JG/T 436-2014 Standard Scope and Construction Controls

Manufactured in accordance with JG/T 436-2014 for insulated sealed air valves.
Execution Standard

JG/T 436-2014 Standard

Fabricated in compliance with JG/T 436-2014 execution standard for building ventilation insulated sealed valves.

Sealing Assembly

EPDM Blade Co-Extrusion

Precision EPDM elastomeric blade gaskets and thermal break side seals co-assembled into opposed-blade profiles.

Submittals

Certified Dimension Sheets

Factory submittal drawings detailing casing length, insulation thickness, and actuator clearances provided upon order.

Disclosure: JG/T 436-2014 is the documented standard. For projects specifying AMCA 500-D or EN 1751 Class 4 test compliance, request verified laboratory reports.
06 / Architectural Boundaries

Insulated Dampers Do Not Replace Every Low-Leakage Component

Use F-BW when airflow control must be combined with thermal insulation and anti-condensation. Do not misapply to fire or Ex duties.

Fire Safety Barriers

If the primary requirement is fire compartmentation, use a dedicated fire damper (FHF 70 °C / PFHF 280 °C) rather than F-BW.

Fire Damper Boundary

Hazardous Atmospheres

If installation is in a classified hazardous gas zone, use a documented explosion-proof damper (BFHF/BFD) carrying Ex d IIC T6 Gb marking.

Ex Hazardous Boundary

Pressure-Independent VAV

If the system requires pressure-independent zone airflow modulation with integrated sensors, use a VAV terminal rather than an insulated control damper.

VAV Terminal Routing
ALERTS — NOT PART OF THE PAGE. RESOLVE BEFORE PUBLISHING.
The source classification table labels DM as “low-airtight,” yet the electric and pneumatic DM F-BW variants are stated at ≤1.2 m³/(m²·h) leakage under 2,000 Pa. Confirm the intended leakage-grade terminology and mapping before publication.
The ≤1.2 m³/(m²·h) value is documented for electric and pneumatic F-BW variants, not separately for the manual F-BW-SD variant.
The source provides leakage-grade codes LX, GM, ZM and DM but does not publish numerical limits for every grade.
Supplier credibility evidence is insufficient for the required five-part audit: manufacturing status/location, batch testing, application laboratory and family-specific supply-continuity data are not documented.
07 / Technical Q&A

Airtight & Insulated Dampers Frequently Asked Questions

Direct engineering answers covering condensation prevention, leakage rates under 2,000 Pa, actuator voltages, and body lengths.

Which YONGFAN damper is intended for cold-air and anti-condensation service?

Use the F-BW Airtight & Insulated Damper family. It combines insulated body construction with EPDM blade sealing.

What leakage does YONGFAN publish for the electric insulated damper?

The F-BW-D source states leakage per unit area of ≤1.2 m³/(m²·h) at 2,000 Pa static-pressure difference.

Does the pneumatic version have the same published leakage figure?

Yes. The F-BW-QD source also states ≤1.2 m³/(m²·h) at 2,000 Pa.

What actuator voltages are documented for the electric version?

The F-BW-D source lists AC/DC 24 V and AC 220 V.

Can the manual version be adjusted continuously?

Yes. The F-BW-SD uses a handwheel with continuous stepless blade-angle adjustment and a self-locking position function.

What materials are available?

The documented F-BW manual, electric and pneumatic variants use hot-dip galvanized sheet or stainless steel sheet.

What body length is available?

YONGFAN documents standard body length of ≥210 mm and customization within 180 < L < 500 mm.

Is F-BW the same as a fire damper?

No. F-BW is an insulated sealed air-volume-control family. For fire or smoke-control functions, use the appropriate FHF, PFHF or PYF family.

08 / Application Engineering Handoff

Select an Airtight Insulated Damper

Connect duct temperature, leakage requirement, actuator logic, material, body length and service access into one confirmed configuration. Send your cold-air schedule to our application engineers.

≤1.2 m³/(m²·h) @ 2,000 Pa EPDM Blade Rubber Seals Insulated Thermal Break Body F-BW-SD Manual Handwheel F-BW-D Electric (24V / 220V) F-BW-QD Pneumatic Actuator Length ≥210 mm (180–500 custom)
Select an Insulated Damper Go to Selection Center Ask an HVAC Engineer
YONGFAN application engineers reviewing airtight insulated damper submittals
Direct Technical Selection Support
Thermal resistance calculations, leakage test data, and dimensioned CAD drawings.
YONGFAN HVAC - Premium Footer