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Engineering & R&D

Engineering Starts
With the Application.

At YONGFAN, engineering is not limited to creating a product drawing. The real question is whether the equipment will perform correctly once it becomes part of an operating HVAC system.

That means understanding the conditions around the product

Airflow, pressure, temperature, humidity, contamination, water quality, available space, control strategy, maintenance requirements and applicable duty conditions.

Product selectionProject adaptation Technical documentationContinuous improvement
Airside · Hydronic · Controls Engineers reviewing technical drawings together
Connecting product capability with project requirement Before final equipment configuration is confirmed.
FIG. 01 Engineers discussing project data on a whiteboard
01 / Application Engineering

The Product Has to Work
Outside the Catalogue.

Catalogue data defines a standard product. Projects define the conditions under which that product must actually operate. The two are not always identical.

A fan may need to operate against higher duct resistance. A filter may have to achieve a target efficiency within a strict pressure-drop limit. A heat exchanger may need a different material because of chloride concentration or water quality. A VAV terminal may need to fit into a restricted ceiling void. A control valve may need to replace an existing product without modifying the surrounding pipework.

YONGFAN engineering work focuses on connecting Product Capability with Project Requirement before final equipment configuration is confirmed.

02 / Our Engineering Approach

Define → Select →
Configure → Verify.

The engineering process can be understood in four stages — from identifying the operating requirement to verifying the final configuration against it, before production or release.

Duty-basedArchitecture-firstConfiguredVerified
01

Define the Operating Requirement

Airflow, pressure, temperature, humidity, noise, filtration efficiency, water quality, target gases, installation dimensions, electrical and control requirements — understand the application before deciding the product.

02

Select the Product Architecture

Not only “which model?” but “which type of product is right for this problem?” — axial vs. centrifugal, primary vs. HEPA, plate vs. tubular exchanger.

03

Configure the Product

Size, material, motor, blade angle, filter grade, pressure class, actuator, control method and accessories — defined once the product family is selected.

04

Verify Against the Requirement

The final configuration is checked against the operating requirement — reducing the gap between catalogue performance and actual system performance.

FIG. 02 Rooftop packaged HVAC ventilation equipment
03 / Airside Engineering

Airflow Is Only One Part
of Fan Selection.

The same fan can deliver very different airflow depending on system resistance. Engineering selection therefore considers airflow, pressure, temperature, noise, installation and duty together — not airflow in isolation.

What airflow is required?
What is the system resistance?
Supplying or exhausting?
Continuous or intermittent?
Is the air hot, dusty or corrosive?
Hazardous-area installation?
04 / Fan Architectures

Why One Fan Type Cannot
Cover Every Application.

Different fan designs solve different system problems. Choosing the correct architecture comes before choosing the model number.

Axial Fans

High airflow with low or moderate resistance — general ventilation, smoke exhaust and industrial air movement.

Mixed-Flow Fans

Axial-style compactness with higher pressure capability — where duct resistance exceeds a conventional axial fan.

Centrifugal Fans

Higher pressure capability for ducted systems, process ventilation and demanding resistance conditions.

Roof Fans

Compact roof-level exhaust arrangement for buildings and industrial spaces.

Bifurcated Fans

Separate the motor from the airstream — suited to hotter, corrosive or difficult air. E.g. T35-11 / BT35-11 bypass design.

Tunnel Jet Fans

Selected by thrust and tunnel aerodynamics rather than conventional duct static pressure alone.

This is a good example of why application engineering cannot be reduced to one universal fan-selection method.
05 / Tunnel Ventilation

When Airflow Becomes a
System-Level Calculation.

Tunnel ventilation is one of the clearest examples of application-led engineering — selection depends on the whole tunnel system, not fan diameter alone.

Aerial view of a road tunnel entrance with ambient lighting
Longitudinal ventilation strategy Thrust, spacing and arrangement calculated against normal and emergency airflow requirements.
GeometryTunnel length & cross-sectional area
TrafficVehicle volume & speed
Air QualityCO / NOx limits & velocity
Fire ScenarioSmoke-control strategy

The engineering question is: how many fans, of what thrust, in what arrangement, are required to create the specified longitudinal airflow under both normal and emergency conditions?

06 / Filtration Engineering

Efficiency Must Be Balanced
Against Resistance.

Air filtration engineering is not a race to install the highest possible filter grade. Every filter introduces resistance — correct design considers the entire filtration train.

Target cleanlinessInitial & final resistanceService life
STAGE 01

Primary Filtration

Removes coarse dust and protects downstream equipment.

STAGE 02

Medium Filtration

Reduces finer particles and extends the service life of high-efficiency filters.

STAGE 03

HEPA / ULPA Filtration

Final-stage high-efficiency particle control for clean or critical environments.

STAGE 04

Activated Carbon / Gas-Phase

Targets gases and molecular contamination rather than particles.

Laboratory technician in protective gear walking through a cleanroom corridor
Confirmed through applicable filtration and resistance tests YONGFAN filtration documentation supports grade, size and resistance selection across the filtration train.
07 / Chemical Filtration Engineering

First Identify
the Contaminant.

A conventional filter can capture dust — it cannot remove molecular gases with a finer particle filter. Gas-phase engineering begins with what gas is present, and what the objective is.

Industrial control panel with gauges and switches OBJECTIVE 01

Corrosion-Control Applications

Protect control rooms, server rooms, instrument rooms and electrical equipment — through filtered outside air, recirculation air, or both.

Industrial pipes with control valves in a plant room OBJECTIVE 02

Exhaust-Treatment Applications

Remove contaminants from a process exhaust stream before discharge — a distinct duty from occupied-space protection.

Target gasesConcentrationRemoval efficiencyContact timeReplacement strategy
FIG. 03 Industrial storage tank and steel structures under a clear sky
08 / Heat-Exchange Engineering

Thermal Duty Comes
Before Physical Size.

Heat exchangers are sometimes procured by connection size or approximate capacity. A proper engineering selection begins with the thermal balance — heat source, inlet/outlet temperatures, flow, load, medium, pressure and water quality.

SUS304316 / 316L321 / 316TiCopperTitaniumHastelloy

The correct material is not simply the strongest or most expensive one — it is the material that provides required compatibility at a reasonable lifecycle cost.

FIG. 04 Close-up of industrial pipes with pressure gauges and valves
09 / Hydronic Engineering

Water Systems Need
More Than a Pipe Diameter.

HVAC water systems depend on the interaction between pumps, pressure, expansion, flow, heat exchange, valves, water quality and control. The engineering objective is to protect the stability and efficiency of the complete water loop.

Pressure StabilizationSystem volume, static & operating pressure, expansion
Water SupplyRequired flow, head, incoming pressure, peak demand
ManifoldsTotal flow, branch quantity, pipe diameter, pressure class
Water TreatmentChemistry, hardness, temperature, pipe size
FIG. 05 Industrial valve actuator with handwheel mounted on rail
10 / Controls & Valve Engineering

Control Is About
System Response.

A valve does not simply open and close — it affects system flow, differential pressure, coil output, pump operation and terminal comfort. Control equipment must be selected with the sequence of operation in mind.

2-pipe or 4-pipe system
On/off or modulating
Actuator voltage
Existing control compatibility
FIG. 06 Engineer in safety gear using a tablet inside an industrial factory
11 / Retrofit Engineering

Existing Conditions
Change the Design Problem.

New construction starts from a drawing. Retrofit projects start from reality — fixed duct dimensions, limited ceiling space, non-standard filter frames, old valve footprints, existing control wiring and restricted shutdown windows.

The question becomes: how can we improve or replace the component without unnecessarily rebuilding the surrounding system? Interchangeable flange dimensions and compatible configurations can significantly reduce field work in retrofit projects.

12 / Documentation & Verification

A Decision Has to Be
Communicated Clearly.

A correct selection is only useful when the rest of the project team can verify it. Engineering support includes performance curves, dimensions, datasheets, schedules and installation drawings.

ManufacturerYONGFAN
ConsultantDesign review
ContractorProcurement
InstallerSite works
OperatorCommissioning
01Design
02Manufacture
03Test
04Compare
05Improve

If measured airflow, resistance, noise, vibration or thermal performance differs from the intended design, the result can point to improvements in geometry, material, configuration, manufacturing tolerance, or selection guidance.

13 / R&D Driven by Real Applications

Improve What Matters
in the Field.

For YONGFAN, product development is most valuable when it addresses a practical operating problem — not a specification exercise.

01

Lower Resistance

Reducing unnecessary airside pressure loss can reduce fan energy.

02

Lower Noise

Impeller, casing and system configuration optimized for occupied environments.

03

Better Maintainability

Removable, replaceable or serviceable components reduce lifecycle effort.

04

Wider Duty Coverage

Multiple blade angles, motor speeds and materials cover more operating conditions.

05

Easier Retrofit

Compatible dimensions and connection interfaces reduce site modification.

06

Application-Specific Materials

Corrosion-resistant or high-temperature configurations extend into demanding environments.

14 / Standardization & Customization

Standardize Where It Helps.
Customize Where It Adds Value.

Too much customization increases complexity. Good engineering standardizes what can be standardized while changing only what the application genuinely requires.

Standard Models

For common applications — predictable lead time and replacement availability.

Defined Options

For frequently changing requirements — configured within a controlled platform.

Project Customization

Only where standard configurations cannot satisfy the application.

Production consistencyReplacement availabilitySpare-part managementLead-time predictability
15 / Work With Our Engineering Team

The Better the Input,
the Better the Selection.

You do not need to know the final model before contacting YONGFAN. Start with the available design information for your product type.

For VentilationAirflow + Pressure + Temperature + Noise + Application
For FiltrationAirflow + Required Efficiency + Resistance Limit + Installation Size
For Gas-Phase FiltrationAirflow + Target Gas + Concentration + Protection / Treatment
For Heat ExchangeHeat Source + Temperatures + Load + Flow + Medium + Water Quality
For Hydronic EquipmentFlow + Head + Pressure + Temperature + System Volume
For Controls & ValvesFunction + DN + Flow + Pressure + Control Method + Voltage