The method you described may provide some temporary relief by creating a cooler environment in the room. However, it is not an efficient or sustainable way to optimize cooling costs in the long run. Let's break down the steps and examine the implications:
Turning the AC on and running it at the lowest temperature for 10 minutes: This step will cool down the room initially, but running the AC at the lowest temperature for only a short duration may not allow sufficient time for the room to reach a comfortable temperature. Additionally, setting the AC to its lowest temperature consumes more energy, resulting in higher cooling costs.
Switching off the AC: Once you turn off the AC, the room will start to warm up gradually as heat from outside enters the space. The rate at which the room warms up will depend on factors such as insulation, outdoor temperature, and sunlight exposure.
Turning the fan on: The fan does not actually cool the room but creates a breeze that enhances the evaporative cooling effect on your skin. The fan circulates the air, which can provide some comfort by increasing air movement and evaporation of sweat from your body, giving the sensation of being cooler.
However, relying solely on a fan to maintain a comfortable temperature for several hours in a hot country may not be sufficient, especially during periods of high heat or humidity. The fan does not remove heat from the room; it only provides subjective cooling through increased air circulation.
In terms of optimizing cooling costs, it is generally more efficient to maintain a consistent temperature with the AC rather than repeatedly turning it on and off. Air conditioners are designed to operate efficiently when running continuously for longer periods, as they reach their peak efficiency after running for a while. Frequent on-off cycles can lead to energy wastage and potential wear and tear on the AC unit.
For cost-effective cooling, it is recommended to set the AC to a moderate temperature that is comfortable for you and use energy-saving settings, such as programmable thermostats, to regulate the cooling based on occupancy and preferred timings. Additionally, improving insulation, sealing windows and doors, using window coverings, and reducing heat sources can help maintain a cooler indoor environment and lower cooling costs in the long term.