Clarifying the Cost of Using Fans vs. Air Conditioners: Surprising Results from a Real-Life Test

To answer the question, “Does running a fan all night consume a lot of electricity?”, many individuals have conducted their own at-home experiments. One such case is from Mr. K. Hung, a user who directly measured his fan's electricity consumption using a specialized power meter.

According to Mr. Hung, the fan was run continuously for about 8 to 9 hours overnight, set at a medium wind level. The power meter was connected directly throughout the operation to ensure the highest level of accuracy.

Does Running a Fan All Day and Night Use More Power Than an Air Conditioner?

The results showed that the electricity consumption was only around 250W—equivalent to less than 1,000 VND (Vietnamese Dong) for an entire night’s use. In comparison, a previous test conducted under the same time duration but using an air conditioner set to 26°C (in cooling mode with auto fan) showed that the fan used only 1/5 of the electricity cost of the air conditioner.

Running a Fan All Day and Night – Is It Wasteful or Not?

From the test above, it's clear that using a fan all night—or even all day during hot weather—is not as expensive as many people believe. However, the actual electricity consumption depends on the type and power rating of the fan being used.

Mr. Hung also noted that his fan had been used for many years, meaning its performance was no longer optimal. With a newer, more energy-efficient fan, electricity usage could be even lower.

Combining a Fan and Air Conditioner – Thought to Be Wasteful, but Actually Saves Energy

Not only did Mr. Hung measure the fan’s electricity usage, but he also shared a smart summer tip: using both a fan and air conditioner together. Many assume that running both will drive electricity bills sky-high, but in reality, the opposite is true.

Many users have shared that using a fan while the air conditioner is running helps cool the room faster and makes the air more comfortable, even when the AC is set at a moderate temperature (around 27°C). This method of cooling has even been recommended by Vietnam Electricity (EVN), especially during peak heatwaves, as an energy-saving and effective cooling solution.

EVN explained that the lower you set the AC temperature, the harder it has to work, resulting in higher power usage and the risk of overloading. Using a fan helps circulate cool air, reduces the load on the AC, and in turn, saves electricity and prolongs the life of the appliance.

Why Use a Fan with an Air Conditioner?

• Faster cooling circulation: Air conditioners need time to cool a room. When combined with a fan, the cool air is evenly distributed, improving cooling efficiency.

• Set the AC at a reasonable temperature: With fan support, you don’t need to set the air conditioner to very low temperatures. This protects your health and reduces issues like dry skin or sore throat caused by prolonged exposure to cold air.

• Protect your appliances: The AC doesn’t have to work as hard when supported by a fan, leading to more durable operation, fewer breakdowns, and reduced electricity usage.

Tips to Optimize Electricity Usage When Using Fans and Air Conditioners Together

• Keep the room relatively sealed: Close doors and windows to retain cool air and avoid energy loss.

• Limit direct sunlight: Use curtains during the day to naturally reduce room temperature.

• Use misting fans if humidity is needed: Ideal for air-conditioned spaces to prevent dry skin.

• Clean appliances regularly: Both fans and AC units should be cleaned periodically for optimal and energy-efficient performance.

Conclusion

Based on real measurements and operational analysis, it’s clear that running a fan all night consumes very little electricity and is a much more economical choice compared to using an air conditioner. And by combining both appliances smartly, you can significantly cut electricity costs while improving the quality of your living space during the sweltering summer months.