The question we hear almost every week. “Do you have a 7,3 meter fan?” The answer is simple, bigger is not always better because bigger fans don’t always move more air. We have tested and researched extensively and refined our design for optimum efficiency.
The blade pitch and aerodynamic shape of the blades is crucial. If the blades are flat and shaped incorrectly the fan wouldn’t move air at all. The 7,3m fan referred to, has weak blade pitch and are not dynamically shaped.
What is the fan output?
This is a good question that it requires a reliable answer.
The airflow of a fan is measured in m³ air /min or /hr. That is the airflow the fan moves per hour. It’s good to ask, but how do you know that these numbers are reliable?
There is only one testing agency in the world which can independently test HVLS ceiling fans. Is AMCA the Air Movement and Control Association. If a fan model is tested it can be found on their website. To do this test is really expensive so most fans are not tested.
If there is no independent test available the easiest way is to see a working fan and check the output by using an anemometer (a windmeter kite surfers use to measure windspeed) together with an Amp meter.
With the anemometer measure the average wind speed from the fan multiply this by the area (fan speed in km/hr x ¼ x 3.14 x fan diameter² = airflow in m³/hr). This will give a rough output for the fan output in m³/hr.
It’s also important to consider and measure the electricity usage at full speed using an ampere meter.
High-Volume-Low-Speed fans are equiped with special motors, controllers and sometimes gearboxes to provide a high torque at low speeds. These fans are designed to be Durable, Quiet and Efficient.
To cover any large area above 200m2 with regular fans it would require many small fans.
A fan makes it 'feel' up to 8 degrees cooler because of the evaporative cooling effect. When air flows over the skin a heat exchange takes place between the human body and the environment. This amount of heat exchange depends on temperature, humidity and air flow over the skin surface. Test shows that significant skin cooling is achieved at wind speeds of 0,6m/s or 2km/hr.
With an average temperature in Ho Chi Minh City around 30°C having a good fan is a must.
With land prices, energy costs and salaries increasing large spaces efficiently and keeping everyone productive having a constant airflow over the entire floor is important.
One of the most cost-efficient possibilities to reduce the factory floor temperature is the use of a ceiling fan. A big ceiling fan provides a continuous air flow. This stimulates evaporative cooling on the skin and the feel like temperatures decreases.