Explore Dongil International's comprehensive range of industrial fans and ventilation solutions — engineered for efficiency, reliability, and performance across every application.
High-performance centrifugal fans for HVAC, underground ventilation, firefighting smoke control, and industrial applications
Propeller-type fans for large-volume low-pressure ventilation, cooling towers, duct installations, and industrial rooftop exhaust
Wall-mounted, plastic ventilation, and high-volume low-speed ceiling fans for residential, commercial, and industrial spaces
Complete range of genuine Dongil accessories for installation, integration, and long-term fan system performance
Dongil International supplies a complete range of accessories to ensure proper installation and optimal performance of every fan system. All accessories are matched and tested for compatibility with Dongil fan products.
Understanding the fundamental principles behind fan performance helps engineers and project managers select the right solution the first time.
The quantity of air moved by the fan per unit time. It is the most fundamental parameter in fan selection and determines the ventilation capacity of a system.
Units: m³/min | m³/hr | CFM
Cubic Feet per Minute (CFM) is commonly used in non-metric regions
The force air exerts on surfaces parallel to the direction of airflow. Represents the resistance the fan must overcome — duct friction, filters, coils, and fittings all contribute to static pressure losses.
Units: Pa | mmAq | mmH₂O
1 mmAq ≈ 9.81 Pa
The velocity energy of moving air converted into pressure energy. Dynamic pressure increases with the square of air velocity and represents the kinetic energy component of airflow.
Pd = ½ × ρ × V²
ρ = air density (kg/m³), V = velocity (m/s)
The sum of static pressure and dynamic pressure at any point in the airflow system. Total pressure represents the complete energy state of the airstream.
Pt = Ps + Pd
Used to determine total fan work output
Fan efficiency is the ratio of air power output to the shaft power input. Two types are used in fan engineering:
Total Pressure Efficiency (ηt)
Based on total pressure rise across the fan. Used when comparing fan performance including velocity energy at the outlet.
ηt = (Q × Pt) / (1000 × Ps_input)
Static Pressure Efficiency (ηs)
Based on static pressure only. The most practically relevant metric for duct system design where outlet velocity energy is lost.
ηs = (Q × Ps) / (1000 × P_shaft)
Air Foil (backward-curved) fans achieve the highest efficiency (70–85%), while Sirocco (forward-curved) fans trade efficiency (40–60%) for high volume at low pressure.
Our engineering team at Dongil International Cambodia is ready to help you select the right fan for your project. Share your airflow requirements and we'll provide a recommendation and competitive quote.