Why Isn’t the Air Conditioner Cool Enough When It’s Extremely Hot?

In the midst of scorching heat, many people choose to stay indoors during peak sunlight hours and use air conditioning to “avoid the heat.” However, many complain that even when set to low temperatures, the air conditioning does not feel cool enough.

What causes air conditioning not to be cool enough during peak heat days? (Illustrative image: Internet).

Here are the main reasons why your home air conditioning may not feel cool enough during peak heat days.

Installing the Air Conditioning Unit in a Hot Corner

Many families in apartments or small houses have limited options for suitable installation corners. Additionally, some believe that placing the air conditioning unit in a hot corner will quickly cool the area. This can lead to the air conditioning unit working overtime, first cooling the overheated wall before addressing the air in the room.

Especially on days when outdoor temperatures exceed 40 degrees Celsius, placing the air conditioning unit in a hot corner exposed to direct sunlight will cause it to operate continuously without achieving the expected level of cooling.

It is recommended to install the air conditioning unit in cooler corners to rapidly lower the room temperature before gradually cooling the surrounding walls. However, be cautious not to extend the connecting system between the indoor and outdoor units too long, as this can hinder optimal performance.

Consistently Setting the Air Conditioning Temperature Too Low

Setting the temperature too low can lead to air conditioning overload. (Illustrative image: Internet)

During hot days, many families tend to set the air conditioning to the lowest temperature for cooling. However, maintaining a low temperature continuously can lead to the air conditioning being overloaded or significantly reducing its lifespan.

Moreover, setting the temperature too low is not good for health, as a significant temperature difference between indoors and outdoors can lead to “thermal shock.” Experts recommend setting the air conditioning at around 25 degrees Celsius or just 5 – 7 degrees Celsius below the outdoor temperature, regardless of how hot it may be.

According to recommendations from Vietnam Electricity (EVN), users should only set air conditioning to 26 degrees Celsius to save electricity while reducing the risk of localized power overload, and to minimize sudden spikes in electricity bills.

A small tip to help you feel cooler is to use an electric fan. The airflow from the fan combined with the cool air from the air conditioning will provide a more refreshing experience than relying solely on the air conditioning.

Insufficient Air Conditioning Capacity

The capacity of the air conditioning unit affects several factors: building materials, heat sources affecting the room, the number of occupants, and usage frequency. Therefore, not every room has the same standards. Insufficient cooling is often found in households with many occupants, overly spacious and open areas; or in workplaces with numerous people, various heating machines, or excessive foot traffic.

To avoid this situation, prospective buyers should consider adding or subtracting around 5 – 10 cubic meters per capacity when purchasing an air conditioning unit. If the room is directly exposed to sunlight, connected to other rooms, or has exhaust fans, consider adding an additional 0.3 – 0.5 horsepower depending on the heat loss.

Air Conditioning Cannot Cool Due to Low Refrigerant

For older air conditioning units that have been in use for several years and have long ducts, small leaks may not show symptoms until after a year. Therefore, if the air conditioning still feels warm after a thorough cleaning, it’s necessary to check the refrigerant levels. If you recently refilled the refrigerant but the air conditioning is still not cooling, it’s essential to find and fix the leak before refilling again. Refilling without checking will only result in the refrigerant running out again shortly after.

In newly installed air conditioning units, if cooling is inadequate, it may be due to leaks in the gas connection points which can lead to the refrigerant running out overnight (especially in inverter units). In this case, users should call a technician to inspect the welding points.

Air Conditioning is Overloaded from Continuous Operation

On days when outdoor temperatures exceed 40 degrees Celsius and scorching heat prevails, many families continuously use air conditioning to stay cool.

An overloaded air conditioning unit is common during excessively hot weather. Since the air conditioning is not cooling sufficiently, users tend to set the temperature too low, further exacerbating the overload situation and causing inefficient operation.

If this continues, the air conditioning may fail its capacitor or, worse, its compressor, leading to significant repair costs. Capacitors are typically rated to withstand temperatures of up to 45 degrees Celsius, and with outdoor temperatures around 40 degrees Celsius, the inside of the unit can reach 50-60 degrees Celsius, risking capacitor failure.

Therefore, allow the air conditioning unit to rest. During cooler periods (early morning or evening), turn off the air conditioning and open windows to let in fresh air. Similarly, if it’s not excessively hot, you can turn off the air conditioning while sleeping. Your body can tolerate higher temperatures while at rest.

Installing the Air Conditioning Unit Facing the Wind Direction

In windy areas, do not install the air conditioning unit facing the wind direction, as the wind will disperse the cool air and cause the unit to work harder to provide adequate cooling. Ideally, the air conditioning should be installed perpendicular to the wind direction.

The Air Filter of the Air Conditioning is “Problematic”

A dirty air filter can reduce the efficiency of the unit and lead to issues like freezing. (Illustrative image: Internet).

Maintaining optimal temperature stability in air conditioning heavily relies on the cleanliness and ventilation of both the indoor and outdoor units. To ensure adequate cold air supply, regularly clean the outdoor and indoor units to prevent dust accumulation.

New air conditioning units typically do not encounter these issues. However, older units (around 2 years of use) that have not been properly cleaned and maintained can become very dirty. Accumulated dust, dirt, and cobwebs can form a sticky layer. If this occurs in the filter of the indoor unit, it can prevent the air conditioning from blowing cool air into the room. In the outdoor unit, it can lead to blockages, hindering heat dissipation when the air conditioning is in operation.

The air filter is an essential component of each air conditioning unit that removes dust and debris from the air before it is circulated into your home. Most air filters need to be cleaned or replaced monthly, although some high-efficiency filters may last longer. A dirty air filter can reduce the unit’s efficiency and lead to problems like freezing.

If your air conditioning unit has a reusable filter, clean the filter under cold running water and allow it to dry completely before reinstalling. If in doubt, replace the air filter according to the manufacturer’s recommendations to ensure optimal performance.

Air Conditioning is Leaking Water

Long-term water leakage from the air conditioning unit can create a layer of mold in the drainage pipe, causing blockages that prevent water from draining outside. This significantly reduces the unit’s cooling capacity.

Contact a maintenance center immediately for cleaning or replacing the drainage pipe.

Note: The drainage pipe should have a sufficient slope for water to easily flow out.

Faulty Capacitors, Circuit Boards

Faulty capacitors or circuit boards will turn the air conditioning unit into a regular fan.

Common Causes:

• Air conditioner is overloaded.
• The air conditioner is maintained at a temperature that is too low (below 20 degrees Celsius) continuously for too long.

Solutions:

• Contact the maintenance center to replace the capacitor and circuit board.
• To minimize damage to the capacitor, it is advisable to maintain the air conditioner at a temperature range of 25 – 27 degrees Celsius.
• Regularly clean the circuit board to promptly prevent insects and spiders from nesting, which can cause short circuits. Ensure the power is turned off during cleaning for user safety.

Compressor Malfunction

There are many reasons for compressor failure such as control circuit errors, power supply failure, etc.

The compressor is a crucial component of the air conditioner; when it fails, the air conditioner may still operate normally, but the air blowing from it will not be cooled.

There are many causes of compressor failure: power loss, control circuit faults, etc.

This component requires professional technicians to promptly check and fix the issue, avoiding unnecessary expenses from customers replacing the entire unit themselves.

Incorrect Cooling Mode Setting

Incorrectly setting the cooling mode is one of the reasons your air conditioner may not cool effectively. This can happen if you accidentally turned on a different function button such as heating or fan mode.

To ensure you have selected the correct cooling mode, you need to understand the different symbols. Some common symbols you need to know are:

• Cool: Snowflake symbol
• Dry: Water droplet symbol
• Heating mode: Sun symbol
• Auto mode.

Compressor Not Running

If the compressor is not running, it can also lead to the air conditioner not cooling. The reasons for this may include:

• The compressor is not receiving power: This could be due to a control board issue, a broken circuit, or the contactor not closing.
• Thermal protection for the compressor: This may be caused by a faulty capacitor, a broken outdoor fan, or inefficient compressor motor operation.
• Burnt motor coil inside.

To resolve this issue, you first need to accurately identify the reason for the compressor not running. If it is due to a burnt motor coil, it is advisable to replace it as repairs may only work for a limited time.

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