Life Hacks in Japan

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"Life in Japan 2023" Here is how to choose a fan and recommended manufacturers!

Fans that look simple but vary widely in price, ranging from about 5,000 yen to 30,000 yen. The more expensive, the more sophisticated? Can it be used with a circulator? Let's sort out the main points and buy the right fan for you!

Before I get down to business, I will address two questions.

As you all know, fans are representative of appliances that are highly commoditized, with little difference in performance. It is not the case that the more money you accumulate, the stronger and quieter they become.

I searched for relevant papers, and indeed there were reports of experiments that showed that the way the blades were grooved changed the amount of airflow delivered in front per revolution.

A 32% increase in efficiency was achieved with F3:1, in which grooves 2 mm wide x 0.7 mm deep were dug on the surface so that the ratio of the distance from the front to the rear edge was 1:3, respectively. A 21% increase in efficiency was achieved with B3:1, in which a groove 2 mm wide × 0.7 mm deep was dug on the back surface so that the ratio of the distance from the front to the back was 3 : 1.
Increased efficiency of fan propellers - Simple surface treatment to change the wind


However, it would save much more money to buy an ordinary fan than to spend tens of thousands of dollars on a fan with blades developed in the latest research for such a small amount of efficiency.

Question 2: Will there be a difference in brade noise?

In the paper "Noise Reduction of Propeller Fans for Air Conditioning," the construction of the blades to reduce noise was shown, but even so, it only changed by 4 dB. In other words, we believe that the noise level is mainly proportional to the air volume, and that this manufacturer's fans do not become quieter at higher wind speeds.

Noise reduction of propeller fans for air conditioning was studied and the following results were obtained.
(1) A noise reduction of 3 dB(A) was obtained for an equal-thickness fan by distributing the airfoil shape in the radial direction around the boss section. The improvement in flow due to the airfoil shape is the reduction of leading edge separation and the equalization of radial blade load due to the reduction of separation near the boss.
(2) The bellmouth shape has a significant effect on the aerodynamic and noise characteristics of the fan, and the shape can control the fan performance to some extent. (1) A 4 dB(A) reduction was achieved by combining the bellmouth with a sequential impeller.
Noise reduction of propeller fans for air conditioning



Some media outlets have stated that "the noise level varies from manufacturer to manufacturer." However, if there is a difference of much more than 4 dB in the measured results despite the same air volume, even with the same output as a fan, let alone a jet plane, and despite the same air volume, we believe that the measurement locations are not standardized or that there is some consideration for a particular manufacturer.

Based on the above, we do not believe that there is a difference in the magnitude of noise from one manufacturer to another, even though there may be a difference in the magnitude of noise from different airflow rates.

Motor type

Here is the main issue.

First, let's look at motors. The characteristics of motors are as follows. Note that AC motors used to have a longer life span, but it has become about the same since the brushless DC motors were created.

  DC motor AC motor
Advantages ・energy conservation
・Fine airflow adjustment
・Low price
disadvantage ・High price ・High power consumption
・No fine adjustment of air volume


However, as you can see from a search on 価格.com and other sites, there are large price differences due to other blades, branding, and availability, so not all AC motors come up first, even if they are listed in order of cheapest to cheapest.

In the first place, I think it is sufficient to have four types of air volume (light, weak, medium, and strong), and it is rather inconvenient to have many types because it increases the number of operations when switching between them. Therefore, in this blog, I will only introduce those with 3 to 4 levels of air volume.

As for the difference in electricity costs, comparing fans from Iris Oyama, which sells fans with both motors, the power consumption is twice as much. However, the power consumption of the fan itself is small to begin with, and even if we assume that the DC motor fan is 25W and the AC motor fan is 50W, the difference is only about 16 yen if the fan is left on for 24 hours. When buying an electric fan, be aware of the balance between the price of the main unit and the cost of electricity.

Shape of wings

This is where the structural difference between a circulator and an electric fan comes into play. While a circulator blows air narrowly and far, an electric fan blows air over a wider and closer area. Thus, because of their opposite characteristics, fans and circulators cannot be used together.

Brushless DC Motor for Electric Fan + Fan Unit | Nidec Corporation



Number of blades

Generally, there are two types: 5-blade type and 7-blade type. For the same shape, 5-blades are quieter and 7-blades are noisier. For motors of the same output, the 5-blade type produces a stronger breeze, while the 7-blade type produces a softer breeze.
About 5-blade and 7-blade fans - Ceiling fans - Panasonic

For this reason, industrial fans designed for use in large areas are usually 3- to 4-blade fans with strong wind. (The image shows an industrial fan.)

NAKATOMI Corporation | Factory Fan


Blade size

They range from 30 ~ 40 cm, but the main one is 30 cm.

remote control

Note that even in this day and age, some may not have a remote control.

Other Functions

Since we consider the up-and-down swivel, temperature sensor, and motion sensor to be of low importance, we will not include them in this blog. As for the sensor, if the sensor is the type that turns on as soon as you turn on the power, you have to turn off the sensor every time you want to reduce the wind power when it is hot or increase the wind power when there is no one around, for example. Therefore, a "fan without a sensor" that does not change the wind power on its own would be more helpful.

Regarding air purifiers, details are written in the following article, but the paper states that the results of the experiment showed that Plasmacluster/Nano-e had no sterilizing effect. Therefore, Panasonic and Sharp products with these functions are omitted from the comparison.



Product Comparison Chart

Therefore, in this blog, we would like to focus on the following fans for comparison.

  • 3~4 levels of air volume adjustment
  • Wing diameter 30 cm
  • With remote control
  • Less than 10,000 yen

5 Blades

Manufacturer technos Yamazen
model number KI-169R YLR-BGT303
motor unknown AC motor
air volume 3 steps 3 steps
Intermittent wind
OFF timer (max) 7.5 hours 8 hours
weight 2.9 kg 3.1 kg
Power consumption 37W(50Hz),
Price*1 4,990 yen 6,780 yen

*1...Prices on Amazon as of April 8, 2023.


Despite equivalent functions, Technos is about 2,000 yen cheaper. However, we consider it difficult to improve efficiency because the motor is a simple mechanism, i.e., greater power consumption = greater wind power, and recommend Yamazen's YLR-BGT303.


7 Blades

Manufacturer Iris Oyama KOIZUMI Iris Oyama
model number LFA-306 KLF-3024 LFD-306L
motor AC motor AC motor DC motor
air volume 3 steps 3 steps 4 steps
Intermittent wind ×
OFF timer (max.) 4 hours 6 hours 4 hours
weight 3.1 kg 3.4 kg 2.9 kg
Power consumption 37W(50Hz),
Price*1 5,825 yen 5,880 yen 7,980 yen

*1...Prices on Amazon as of April 8, 2023.


For a 7-blade fan, the price difference is about 2,000 yen, which is likely due to the difference in motors. Therefore, for this much, we recommend Iris Oyama's LFD-306L, which has an energy-saving DC motor. Is the reason why the air volume adjustment is not fine despite the DC motor, is it to reduce the price of the unit by making the parts common with AC motor fans? Or is it because there is a demand for rough adjustment like mine?

I hope the above is helpful.


See also!