Japanese Self-Defense Force Shares Clever “Bucket + Towel” AC Trick — Simple Method May Help Reduce Heat Around Outdoor Unit In Summer

As extreme heat waves continue pushing temperatures above 35°C across many parts of Asia, a surprisingly simple air-conditioner cooling trick from Japan has recently gone viral online.

What caught people’s attention is that the method was reportedly shared through the official social media account of the Tokyo division of the Japan Ground Self-Defense Force (JGSDF).

The technique uses:

• just a bucket of water,
• and a towel,

to help reduce heat around the outdoor AC compressor during extremely hot weather.

How Does The Trick Work?

The method is simple:

• Place a bucket filled with water next to the outdoor AC unit.
• Dip one end of a towel into the water.
• Drape the rest of the towel across the top of the outdoor compressor unit.

As the towel slowly absorbs water through capillary action, moisture spreads across the fabric surface. Under hot sunlight, the water gradually evaporates, helping cool the surface temperature around the compressor.

Why Cooling The Outdoor Unit Matters

Although the trick looks simple, experts say it actually follows basic air-conditioning engineering principles.

1. Reduces Heat Load On The Compressor

During extremely hot weather, the outdoor unit works harder to release indoor heat outside.

If surrounding temperatures become too high:

• cooling efficiency drops,
• the compressor works harder,
• and electricity usage may increase.

Lowering surrounding heat may indirectly reduce strain on the system.

2. Evaporation Helps Remove Heat

When water evaporates from the wet towel, it absorbs heat energy from nearby surfaces.

This evaporative cooling effect may help the outdoor unit release heat more efficiently.

Does It Really Cut Electricity Bills In Half?

Online rumors claimed the trick could reduce electricity costs by:

“up to 50%.”

However, experts caution that:

• there is currently no official scientific study,
• no verified manufacturer testing,
• and no technical certification

proving such dramatic savings.

The Japanese Self-Defense Force reportedly shared the method mainly as:

• a practical summer survival tip,
• and a way to potentially reduce heat stress on AC systems.

Important Safety Warnings

Experts also warn that using the method incorrectly could damage the air conditioner.Never Block Airflow

The towel should only rest lightly on the top exterior surface.

It must NEVER:

• cover ventilation openings,
• block the fan,
• or obstruct hot air exhaust.

Blocking airflow may:

• reduce cooling performance,
• overheat the motor,
• or damage the system.

Never Pour Water Directly Into The Unit

Although outdoor AC units are designed to withstand rain, directly pouring large amounts of water into electrical components may create risks such as:

• electrical leakage,
• short circuits,
• or equipment damage.

As electricity costs continue rising during intense summer heat, many people online praised the Japanese trick for being:

• simple,
• inexpensive,
• and easy to try at home.

Still, experts remind users that:

proper AC maintenance, clean filters, and good ventilation remain the most important ways to improve efficiency and reduce long-term energy costs.