Common Reasons Your Ceiling Fan Makes Noise

In India, ceiling fans remain the most widely used appliance for thermal comfort, thanks to their simplicity, affordability, and energy efficiency—especially with the advent of BLDC models. While they offer several advantages, they are not without limitations. Challenges such as the absence of standardization, reduced effectiveness in high-humidity environments, and operational noise continue to affect the overall user experience.

Government bodies such as BIS and BEE are currently working on standardizing ceiling fans. However, it’s important to note that ceiling fans alone cannot provide adequate comfort in humid climates, since their cooling effect largely depends on the level of surrounding humidity. Learn more about the science behind how ceiling fans function.

One of the common concerns with ceiling fans is noise. While many leading brands have tried to reduce fan noise, the solutions often come with a trade-off in performance.

Ventumfan has tackled this challenge differently with its latest model, offering a noise-free experience without compromising on cost-effectiveness or performance.

What Causes Ceiling Fan Noise?

1. Mechanical Noise
A ceiling fan is an electromechanical device with continuously moving components. Friction between these parts can generate sound. Common causes include insufficient lubrication in bearings, loose screws in the blade assembly, or resonant vibrations created between the blades and their surroundings.

2. Electronic Noise
BLDC-based, super energy-efficient ceiling fans like Ventumfan use advanced electronics to regulate motor performance. These circuits can sometimes emit faint high-frequency sounds, especially at lower speeds. While such humming is present in certain BLDC fans, it usually remains minimal and is often masked by other types of noise.

3. Air-Cutting Noise
This type of noise comes naturally from how a ceiling fan works—its blades cut through the air to generate airflow. The noise level rises as the fan speed increases, which can be explained by the formula:

$\log \left(\frac{RPM2}{RPM1}\right)$

Where N is the noise level and RPM is the fan speed at two different states.

The airflow from a fan consists of both smooth (laminar) flow and chaotic (turbulent) flow. The turbulence, especially near the blade edges, is the main contributor to air-cutting noise. At maximum speed, a standard ceiling fan may produce sound levels above 60 dBA.

In short, ceiling fan noise is primarily caused by two factors: the frequency of the blades cutting through the air and the turbulence created in the airflow.

How Are Ceiling Fans Made Quieter?

When it comes to reducing ceiling fan noise, engineers focus mainly on air-cutting noise. As explained earlier, this noise originates from the blade edges and increases with the fan’s rotational speed. To deliver adequate comfort, most ceiling fans typically need to run above 350 RPM, which makes noise control a real design challenge.

Traditionally, ceiling fan blades are made of aluminum with a thin foil shape—a flat cross-section of uniform thickness. To tackle noise, many manufacturers have adopted airfoil-shaped blades. An airfoil is a three-dimensional cross-section that comes in various shapes, chosen carefully depending on the application. Well-designed airfoils help in two ways: they reduce turbulent airflow and produce greater airflow at lower RPMs, thereby lowering noise while still maintaining comfort.

Brands such as Orient Aero Quiet and Crompton Silent Pro have introduced fans in India that use this principle. However, these silent fans often come at a higher cost because they are made with plastic blades rather than aluminum.

The reliance on plastics stems from the fact that airfoil-shaped blades require varied thickness along the cross-section, which aluminum cannot easily accommodate. While plastics enable these shapes, they also come with drawbacks—higher costs, reduced productivity due to slower injection molding processes, and in some cases, lower efficiency. Moreover, many of the designs sold in India are adapted from foreign products created for different applications, which means they often lack focus on cost-effectiveness and local performance needs.

Another concern is blade flexibility. Plastic blades have inconsistent stiffness along their length because the material volume changes with the design. This rigidity limits their ability to flex under thrust. By contrast, aluminum blades naturally flex during operation, which appears to reduce energy loss and improve overall efficiency.

How is the Ventumfan Ceiling Fan Different?

Ventumfan has engineered a new blade design that does not rely on the conventional airfoil shape. This innovation allows the blades to be manufactured from aluminum rather than plastic, while still delivering the same quiet operation and strong airflow as airfoil-based blades—only with higher efficiency.

The design ensures powerful performance: a 48” Ventumfan can deliver 230 CMM airflow at just 240 RPM, maintaining a noise level of only 49 dBA measured 7 feet from the fan’s center.

Key Advantages of Ventumfan’s Unique Blade Design:

High airflow with low speed → Comfortable cooling with less noise
Energy savings → 230 CMM airflow achieved with just 25W power
Aluminum construction → Higher efficiency compared to plastic blades
Scalable production → Manufacturing productivity remains similar to that of regular blades, unlike plastic blades which are slower and more costly to produce

With this design, Ventumfan combines quiet performance, energy efficiency, and cost-effectiveness, making it a truly innovative solution for the Indian market.