Features of the BSB HD Series
When specifying a damper for high-velocity HVAC systems you simply cannot settle for “standard.” The difference between a standard volume-control damper and a truly heavy-duty, mission-critical component is real — and the consequences of under-specification can be expensive (and risky). In this article we unpack exactly what it means for a damper to be “heavy duty”, and why the BSB HD Series delivers the features you need.
1. The Definition: “Heavy Duty” in HVAC Dampers
A “heavy duty” air control damper isn’t just a marketing term. At its heart it means:
· a casing and blade assembly built to withstand higher air pressures and velocities than typical units;
· minimal performance compromise (pressure-drop, leakage, durability) in demanding conditions;
· robust construction and materials to maintain performance over repeated cycles in harsh environments.
For example, the BSB HD Series is explicitly described as “designed for use in HVAC systems where high air pressures and velocities are involved” — with noted suitability for duct pressures up to 2 000 Pa and air velocities up to 20 m/s.
These are not the figures of a standard damper meant for low-pressure air-conditioning branch systems; these are the numbers you expect in large AHUs, data centre ventilation, plant-rooms, main returns or extract systems where reliability, durability and performance matter.
2. What Makes the BSB HD Series Heavy Duty?
Let’s break down the key features — and how they translate into practical benefits for you specifying or installing.
Pressure- and velocity-ratings
· The HD Series lists suitability for duct pressures up to 2 000 Pa.
· Velocity capability up to 20 m/s.
These ratings give clear boundaries: when you’re working in a system where you anticipate high static pressures or significant duct velocities (large AHU, data centre, central plant), you need the rated capability.
Large size and flexible connection options
· Case sizes (single section) up to 2 380 mm width x 2 000 mm height for flanged units.
· Spigot styles: up to 2 400 mm width (for 40 mm flange) in a single section.
· Available for rectangular, circular, flat-oval spigot or flanged connection.
This means the HD Series can cover large ductwork sections without resorting to multi-section spliced assemblies (which introduce joins, potential leakage or weakness).
Robust materials and construction
· Standard case construction is galvanised mild steel; optional stainless steel (Grade 430, Grade 316) for blades and case.
· Blades: extruded aluminium airfoil or precision-rolled galvanised/stainless steel mono-rib.
· Enclosed drive mechanism outside the airstream (reducing exposure to contamination or damage) and side-covers on flanged cases to ensure Class C case leakage.
Leakage and performance control
· The HD Series conforms to DW144 (HVAC ductwork specification) and Eurovent 2/2 classes A–C.
· Designed to deliver smooth airflow and minimal pressure drop in large-size configurations.
When you combine high pressure rating, large size, and robust construction you are specifying a component resilient to demanding conditions — that’s what “heavy duty” truly means.
3. Heavy Duty vs Standard Dampers: What You’re Gaining with the HD Series
When comparing a heavy duty damper like the HD Series versus a standard unit for mainstream HVAC, here are the benefits for your project:
· Durability under stress: Standard dampers may be rated for lower pressure (eg 500–1000 Pa) or lower velocities. In a system where velocities or pressures exceed those limits you risk deformation, blade flutter, failure or excessive leakage. With the HD Series rated to 2 000 Pa and 20 m/s, you gain head-room.
· Leakage reduction and efficiency savings: Heavy duty construction, side-covers, robust seals mean lower case leakage and better closed-blade performance. Though the HD “Air Control” variant is not explicitly the “low leakage” variant (that’s the HD-LL or HD-IB), the base HD Series still delivers robust performance.
· Fewer replacements, less maintenance: In a challenging environment (large AHU, data centre, dusty or contaminated air streams), a standard damper may suffer fatigue, wear and tear, misalignment. The HD Series is built for that environment — meaning fewer failures, less downtime and lower lifecycle cost.
· Flexibility with size and connection types: Standard dampers often limit size, drive mechanisms, number of sections. With the HD Series you get large single-section sizes, spigot or flanged, multiple blade options, manual or motorised drives — which reduces the complexity of installation, reduces the number of joints and potential leakage paths.
· Peace of mind for high-end projects: For critical services (data centres, central plant, large commercial HVAC), the specification of heavy duty components reflects best practice and can support project audit, performance warranties, maintenance regimes and longevity.
4. How to Specify a Heavy Duty Damper for High-Velocity HVAC Systems
When you’re the specifier (mechanical contractor, M&E consultant, facilities manager) working on large AHUs, data centre ventilation systems or high-velocity ductwork, you’ll want to apply the following guideline to ensure the right damper is selected:
4.1 Define system demands
· Determine the duct static pressure at the damper location (eg 1 000 Pa, 1 500 Pa, up to 2 000 Pa). Ensure margin for future changes or shock loads.
· Determine the air velocity in m/s. If you expect velocities 15–20 m/s you need a damper rated accordingly (like the HD Series at 20 m/s).
· Define size of duct and layout: large AHU, main discharge/return ducts, plenum-to-duct transitions usually require larger size dampers.
· Define environment: dusty, humid, aggressive air, potential corrosion (this influences material selection: galvanised vs stainless).
· Define control mode: manual hand-lever, extended-spindle, motorised actuator, pneumatic. The HD Series supports manual quadrant, motorised, extended spindle.
4.2 Match the damper to application
Using the HD Series as example:
· For high velocity/high static pressure on a main AHU plant: specify HD Series Air Control Damper (100 mm × 100 mm up to 2 380 × 2 000 mm single section) with galvanised or stainless blades as required.
· If you require enhanced closed-blade leakage performance (e.g., data centres, clean rooms): consider HD-LL (Low Leakage) or HD-IB (Reduced Leakage) variants. (Note: the HD-LL variant is limited to sizes up to 1 000 mm single section for leakage spec continuity).
· Specify material grade: galvanised steel case is standard; for aggressive environments (swimming pool AHU, coastal sites, chemical plant ventilation), specify Grade 430 or 316 stainless steel for blades/case.
· Specify connection type (flanged vs spigotted) and orientation (horizontal or vertical blade). The HD Series supports all major connection types: rectangular/spigot, circular spigot, flat oval.
4.3 Ordering / Sizing quick guide
Here is a quick guide when ordering the BSB HD Series:
· Size range: from 100 × 100 mm up to 2 380 × 2 000 mm (single section width × height) for flanged case. For spigot case up to 2 400 mm width.
· Choose connection: Flanged (HD-F), Spigotfit rectangular/square (HD-S), Circular spigot (HD-C), Flat-oval spigot (HD-O).
· Select blade material: extruded aluminium airfoil, galvanised mild steel, stainless steel (430 or 316) — note environmental demands.
· Choose control mechanism: manual quadrant, extended spindle, motorised actuator (specify actuator type). The HD Series includes factory-fitted 19 mm diameter extended spindle control to actuation by others.
· Specify accessories/options: side-seal gaskets, side covers (for Class C leakage), vertical blade support for DW144 compliance, etc.
· Installation orientation: clarifying whether the damper is mounted in horizontal or vertical duct, selecting correct blade type. Large size dampers might require factory matched drive mechanisms for multi-section variants.
· Provide performance specification: for example: “damper to suit 1 500 Pa static pressure, 18 m/s velocity, to conform to DW144 and Eurovent 2/2 Classes A-C, one-drive single section up to 2 000 mm height, manual/actuated as per schedule.”
4.4 Checklist for specifiers
· Confirm available duct static pressure and velocity.
· Confirm size of duct and space constraints for one-section versus multi-section assemblies.
· Confirm required leakage performance (if clean room/data centre) and temperature/humidity/aggressive air conditions.
· Confirm the blade material and drive mechanism.
· Confirm connection type and on-site installation clearances (for maintenance, actuator access, linkage).
· Ensure that documentation (datasheet) is referenced in the specification, e.g., “BSB HD Series Heavy Duty Air Control Damper: up to 2 000 Pa, up to 20 m/s, DW144/Eurovent 2/2 A-C”.
· Confirm factory testing evidence and third-party verification where required.
5. Why Investing in a Certified Heavy Duty Damper Saves You in the Long Run
The upfront cost of a heavy duty damper may be higher than a standard unit. But when you consider the total cost of ownership over the life of the installation, the advantages become clear:
· Lower maintenance cost: Robust construction means less deformation, fewer blade/shaft link failures, less leakage over time, fewer adjustments and reduced maintenance visits.
· Fewer replacements / downtime: In critical environments (data centres, hospital plant rooms) the cost of downtime or failure is far higher than the cost of the damper itself. A damper failing in a high-pressure, high-velocity main return duct can cause noise, vibration, leakage and system performance impact. The HD Series mitigates this risk.
· Improved system efficiency: Lower leakage, better flow control and minimal pressure drop ensure your system operates closer to design intentions — saving energy and improving comfort or process control.
· Reduced risk & specification compliance: Using a product that meets respected standards (DW144, Eurovent 2/2) and is built for the environment means fewer specification challenges, better performance documentation and fewer surprises at commissioning.
· Future-proofing: As system demands evolve (larger AHU installations, future capacity upgrades, higher fan powers), specifying a heavy duty damper now gives head-room for future performance requirements.
6. Heavy Duty Dampers in High-Risk Environments: What You Need to Know
When we talk “high-risk environment” we mean zones where failure is not an option: data centre air-handling, central plant serving critical processes, high-rise building cores, large-scale ventilation for arenas or tunnels. The BSB HD Series is designed for such scenarios — here are what you need to know:
· Ensure the damper is rated for the maximum static pressure your system might see. Transient events (fan start, surge, shut-down) can exceed typical operating pressures.
· Check that the velocity rating is adequate: 20 m/s is the upper limit quoted for the HD Series. If your system pushes beyond that, you’ll need to review.
· Verify the blade material and environment compatibility: in corrosive or humid environments (chemical plant, swimming pool AHU, coastal exposure) choose stainless steel components. The HD Series offers 430 and 316 grade stainless.
· Consider leakage performance: For high-risk environments you may require the HD-LL (low leakage) or HD-IB (reduced leakage) variants rather than the standard HD. The HD-LL variant is explicitly targeted at clean, mission-critical applications such as data centres.
· Ensure actuator and linkage design: in high-demand installations, motorised actuators (or pneumatic) may be necessary rather than hand-lever/manual. Check for accessible drive mechanisms, service clearance, linkage protection from debris or contamination.
· Document the testing and conformity: record that the damper selected meets DW144, Eurovent, has single section size rating, case leakage class (for example Class C) and blade leakage performance. Provide this in the contract documentation.
· Commission and maintain: even heavy duty dampers require correct installation, periodic inspection of linkage, seals, blade alignment, actuator function. A poor install undermines specification no matter how good the product.
7. Summary
In a world where HVAC systems continue to grow in scale and complexity — from vast data-centres to high-capacity air handling units for commercial towers — the specification of every component matters. A damper is no longer just a passive device; it is a key control point in airflow management, system efficiency, energy cost and operational reliability.
By choosing the BSB HD Series Heavy Duty Air Control Damper you are specifying:
· Rated performance up to 2 000 Pa static pressure and 20 m/s velocity.
· Large single-section sizes (up to 2 380 × 2 000 mm) and flexible connection types.
· Robust materials, construction and drive mechanisms.
· Compliance with DW144 and Eurovent 2/2 standards, with excellent long-term lifecycle value.
This means less risk, fewer surprises at commissioning, more satisfaction for the end-client and a long-term asset that just “works”.
When the system leaves the shop floor and goes live, it is these decisions made at specification stage that determine whether you get a durable, efficient installation — or a site headache down the line.
If you are specifying or tendering for a high-capacity AHU, data centre ventilation system or any HVAC installation with significant static pressure/velocity demands — don’t settle for “standard” dampers. Specify the BSB HD Series and tick the box for performance, durability and compliance. Gather your size/flow/pressure data, talk with us today and ensure your specification includes the full HD Series parameter set.
