The difference between forward curved and backward curved

December 8, 2023

TABLE OF CONTENTS

The front curved propeller and the rear curved propeller are factors that directly affect the operation of the fan. Let’s find out the difference between the front curved propeller and the rear curved propeller below.

The difference between forward curved and backward curved

Fans with forward curved blades

The number of wings is large, the wing part is shallow towards rotation. For this impeller design, the airflow generated by the impeller moves tangentially. The curved shape of the blades imparts kinetic energy to the air, necessitating the use of a scroll housing to transform this kinetic energy into static pressure. When operating at a constant speed, the input power characteristic rises as the airflow increases from zero to its maximum. Consequently, at elevated flow rates, it’s crucial to ensure that the impeller load remains within the motor’s specified rating to prevent any overload issues.

Forward-curved propellers are used for situations where heavy traffic is required at low running speeds. Suitable for applications requiring continuous, constant pressure airflow.

Application

Forward-curved blade fans are widely applied for many cases where high airflow power is preferred, requiring moderate pressure, and relative noise level. Some common apps are as follows:

• Use for HVAC system: Use forward-curved blade fans for cooling ventilation systems, heating systems, and air conditioners … Provide efficient airflow for cooling and ventilation purposes in commercial and residential buildings. ( More: How to Choose Fans for HVAC )

• Air treatment: Used for air handling systems in factories, and industrial and commercial facilities. Ensure good air quality is maintained.

• Electronic device cooling: In electrical equipment such as computer parts, servers, and electronic enclosures.

• General ventilation: Use cooling ventilation for spaces such as warehouses, factories, workshops, malls, etc.

Advantages of anterior curved propellers

• High flow: The front curved propeller has a curved blade design that allows large, efficient airflow movement. By the needs of air circulation.

• Low noise: Works with lower noise levels due to curved blades minimizing turbulence, and reducing noise.

• Cost savings: Production is simpler, which saves production costs.

Restrict

• Low efficiency at high pressure: As the pressure increases, the optimum efficiency of the fan decreases, resulting in reduced airflow and efficiency. Not suitable for needs that need to be subjected to high static pressure.

• Poor static pressure capability: Suitable for relatively low static pressure requirements. The design of forward-curved propellers is optimized to provide large amounts of wind, however, they have difficulty creating significant pressure differences. Therefore, it is not suitable for requirements that need to overcome high resistance or pressure drops.

Cooling fans with backward-curved blades

• Longer number of blades

• Facing away from the direction of rotation

• The propeller is curved posteriorly from the inner edge to the outer edge. Corresponding to the direction of rotation.

• Propellers can be in the form of plates or the form of aircraft wings.

Activity

• As the impeller rotates, generating flow in the radial direction, the impeller creates static pressure over a longer blade length.

• On the front of the impeller, creating positive pressure pushes air out. On the back of the propeller, negative pressure is created. The negative pressure generated draws air in and gives it to the front of the fan. At the front, the airflow is pushed out.

• Application for cases requiring high pressure, high performance such as heat recovery system, extraction ventilation system, smoke extraction system, and high-pressure condensing boiler.

Application

• Fans with rearward-curved blades are suitable for requirements that need higher performance, and good performance at high pressure. Some common applications are as follows:

• HVAC: Used for HVAC systems: cooling ventilation, air conditioning systems, heaters to improve energy efficiency and high static pressure resistance.

• Data centers: Efficient cooling for data centers.

• Industrial cooling: Application for industrial ventilation systems, air control systems, and exhaust gas treatment systems.

Advantage

• High efficiency: The fan has a rearward curved wing design that has high efficiency thanks to the curved blade design, and the large blade size. Good airflow control, reduced energy loss, and improved overall performance.

• Good performance at higher pressures: Handles increased drag, and reduced pressure while maintaining airflow efficiency and capacity. Helps to work well with requirements that require higher static pressure resistance.

• Clean the air in dusty environments: The curved blade design minimizes the accumulation of dust on the blade, increasing the efficiency of air cleaning.

Restrict

• High noise level: Large blades, high airflow power, causing loud noise to the fan when operating.

• High cost: Blades require manufacturing complexity, which in turn increases production costs.

USEFUL INFORMATION

Choose axial fan or centrifugal fan accordingly?

What is the difference between fan and blower?

The difference between a front-curved propeller and a rearwardly curved propeller

	Forward curved	Backward-curved
Number of wings	Fewer wings, higher direction of rotation	The number of wings is more, the long blade is lower, directed away from the direction of rotation
Noise level	Lower noise level	Higher noise level
Wing circumference	More compact design	Larger design
Rotational speed	Slower	Faster

Choice of forward curved blade fan or backward curved wing fan?

The choice of fans with blades curved forward or backward should be considered based on factors to suit the needs of use. Here are some factors:

• Pressure requirements: If a significant pressure difference is required, a fan with blades curved backward should be selected. With relatively low-pressure requirements, it is possible to choose a forward-curved fan with low noise, and high efficiency.

• Noise requirements: In spaces requiring low noise such as offices, apartments, commercial centers, and hospitals … It is recommended to use fans with a pre-curved wing design for maximum noise reduction.

• Environmental conditions: In a fresh air environment, with low dust concentration, it is recommended to use a fan with curved blades first. In an environment with a lot of dirt and high dust concentration, it is necessary to use a fan with an inverted blade to ensure the performance of vacuum and exhaust gas thoroughly.

There are also many other factors, depending on the necessary parameters such as airflow, pressure, and others. Hopefully, the above information will help you choose the right fan line.

Above is information about the difference between the front curved propeller and the rear curved propeller. Please contact us if you want to buy industrial fans.

System Fan

5 1 vote

Article Rating

0 Comments

Oldest

Newest Most Voted

Inline Feedbacks

View all comments

CONTACT US

Northern Vietnam: NV11, Me Tri Ha, Nam Tu Liem, Ha Noi

Phone: +84867853866

Email: export1@systemfan.vn

Factory: Long Xuyen Industrial Park - Kinh Mon - Hai Duong

Phone: +84867853866

Email: export1@systemfan.vn

Czech Republic: Majerskeho 2037/19 , 149 00 Praha 11, Czech Republic

Phone: +84867853866

Email: export1@systemfan.vn

Gürselpasa Mh. Aliya İzzet Begoviç Cd. Üçgül İş Merkezi B Blok No:25 Seyhan/Adana

Phone: +84867853866

Email: export1@systemfan.vn

Ostim OSB Mh. 100. Yıl Blv. No:55 Ostim Prestij İş Merkezi C Blok -No: 44 06374 Yenimahalle - Ankara / Türkiye

Phone: +84867853866

Email: export1@systemfan.vn

Office No. 214, Le Solarium, Nadd Hessa / Silicon Oasis, Dubai, United Arab Emirates.

Phone: +84867853866

Email: export1@systemfan.vn

SEND CONTACT US

Would love your thoughts, please comment.x

()

| Reply

SEND CONTACT US