How Many Cooling Tower Fan Blade Types

Cooling tower fan blades are selected based on airflow requirement, static pressure, efficiency, noise limits, and tower type (BAC, Marley, EVAPCO, etc.). Below is a clear, industry-standard breakdown of cooling tower fan blade types

1. By Blade Construction (Material)

Cooling Tower Fan Blade Types - FRP (Fiber Reinforced Plastic) Blades

Most common in industrial cooling towers

* Lightweight and corrosion-resistant

* High efficiency at large diameters

* Low noise compared to metal

* Used by: **BAC, Marley, EVAPCO, SPX**

✅ Best for: Induced & forced draft towers

❌ Not ideal for very high temperatures (>90–100°C air)

Cooling Tower Fan Blade Types - Aluminum Fan Blades

* Strong and rigid

* Better for high-temperature air

* Heavier than FRP

* More vibration risk if not balanced

✅ Best for: High-temperature or special process towers

❌ Higher noise, corrosion risk

Cooling Tower Fan Blade Types - Stainless Steel Fan Blades

* Very strong and durable

* High corrosion and temperature resistance

* Expensive and heavy

✅ Best for: Chemical / harsh environments

❌ Rare in modern HVAC towers

2. By Blade Geometry (Shape)

Cooling Tower Fan Blade Types - Airfoil Fan Blades

**Most efficient design**

* Aircraft-wing profile

* Highest airflow per kW

* Low turbulence and low noise

✅ Used in: Modern energy-efficient cooling towers

✅ Typical diameter: 2–12 meters

Cooling Tower Fan Blade Types - Flat Fan Blades

* Simple flat plate design

* Lower cost

* Lower efficiency

❌ Rare in modern cooling towers

❌ Higher power consumption

Cooling Tower Fan Blade Types - Hollow Airfoil Blades

* Internal reinforcement

* Extremely strong for large diameters

* Excellent vibration control

✅ Used in: Large natural draft & power plant towers

3. By Blade Pitch (Angle Type)

Cooling Tower Fan Blade Types - Fixed Pitch Blades

* Blade angle set during installation

* Simple and reliable

* Lower cost

✅ Most common for standard HVAC towers

Cooling Tower Fan Blade Types - Adjustable Pitch Blades

* Blade angle can be changed manually

* Allows airflow optimization

* Used for balancing after installation

✅ Common in BAC / Marley towers

Cooling Tower Fan Blade Types - Variable Pitch Blades (Automatic)

* Blade angle changes during operation

* Complex and expensive

* Rare in cooling towers

❌ More common in ventilation systems

4. By Fan Type (Application)

Induced Draft Fan Blades

* Installed at tower top

* Handle hot, moist air

* Larger diameter, lower speed

✅ Most cooling towers today

Forced Draft Fan Blades

* Installed at air inlet

* Smaller diameter, higher speed

* Higher noise level

❌ Less efficient, more maintenance

5. By Number of Blades

Blades	Typical Use
4–6	Small cooling towers
6–8	Medium industrial towers
8–12	Large industrial / power plant towers

More blades = higher static pressure capability, lower RPM.

6. Manufacturer-Specific Blade Types

* BAC: Airfoil FRP adjustable-pitch blades

* Marley: Geareducer-driven hollow FRP airfoil blades

* EVAPCO: Heavy-duty airfoil FRP fan blades

* SPX: High-efficiency low-noise airfoil designs

Quick Selection Guide

Requirement	Recommended Blade
High efficiency	Airfoil FRP
Low noise	Large diameter airfoil
Corrosive water	FRP or SS
High temperature	Aluminum or SS
Retrofit tower	Adjustable pitch FRP