8 Top Reasons Why Your AC is Not Meeting Your Cooling Needs

Few things could be more frustrating than discovering that your air conditioner is blowing out warm air instead of cool air on a hot, muggy day.

Read on for eight possible reasons why your air conditioning unit is not cooling your home.

1. Filthy Filters

The air conditioner is fitted with air filters designed to keep dust, dirt, debris, and pet dander from entering the system.

However, the filters become clogged over time as unwanted particles accumulate in the units. This restricts airflow, reducing the cooling capacity of your air conditioner.

Filthy filters also increase energy consumption and could cause the air conditioning system to shut down. Be sure to clean or replace the filters every three months to maximize your air conditioner’s efficiency.

2. Low Refrigerant Levels

The air conditioning system uses refrigerant (the chemical that moves through the air conditioner coils) to absorb heat from the indoors and transfer it to the outdoors.

When the refrigerant is low, the air conditioner cannot cool your home.

Some of the reasons why the air conditioner’s refrigerant level could be low include refrigerant leaks or the system being undercharged during installation.

Be sure to seek air conditioner service if you notice a build of ice outside your unit or bubbling or hissing noises as these indicate the refrigerant is leaking to get the problem fixed.

3. Compressor Malfunction

The compressor is the heart of your air conditioning unit. It ensures the refrigerant is at optimal pressure to circulate air between the air conditioner’s indoor and outdoor units.

Any issues with the compressor mean the air conditioner cannot absorb heat from the rooms and transfer it outside, making it difficult to cool the house, so you should consider replacing it.

4. Dirty or Frozen Coils

As the air conditioner operates, the condenser coils become dirty over time as they stay humid, making it easy for mold and mildew to build up.

When there are low levels of refrigerant, the coils may also freeze. Dirty and frozen coils cause the air conditioner to become less efficient, preventing it from cooling the house.

5. Wrong Thermostat Setting

If your air conditioner does not cool the home, it could be due to wrong thermostat settings. First, you should check the thermostat to ascertain that it is switched to “COOL” instead of “HEAT.”

Next, check the fan settings. If the thermostat is set to “ON,” it will cause the fan to run continuously to circulate air throughout your space.

This causes air to blow from the vents even when the air conditioner is not cooling the house.

When this happens, the air coming from the ducts has the same temperature as that already in the house, making the home feel warm instead of cooling it.

Always ascertain that the thermostat is set to “AUTO.” An “AUTO” setting makes the fan operate for as long as the air conditioner cycles. When a cycle ends, the fan will automatically turn off.

6. Use of Traditional Inefficient Light Bulbs

Your air conditioning may not be meeting your cooling needs due to traditional light bulbs such as incandescent bulbs and compact fluorescent lightbulbs (CFLs).

These bulbs emit a lot of heat, making it difficult for your air conditioner to cool the home.

Replace traditional bulbs with energy-efficient light-emitting diode (LED) bulbs which emit a significantly lower amount of heat to improve your air conditioner’s efficiency and reduce electricity expenses.

7. Improper Placement of Your Air Conditioning Unit

The air conditioner has two major components: the outdoor unit and the indoor unit, which must be strategically positioned to allow the system to operate without any hitches.

If you place an indoor unit designed for medium-sized rooms in a more vast space or set it near heat-producing appliances, the system will not meet your cooling needs.

Placing the outdoor unit under direct sunlight will cause the unit’s compressor to overheat or shut down.

Be sure to consider the size of your house when purchasing your HVAC system and position the indoor unit away from heat-producing appliances and the outdoor way from the sun to meet your home’s cooling needs.

8. Lack of Regular Air Conditioning System Maintenance

Failing to schedule regular air conditioner inspection and maintenance checks with a reputable heating and cooling Cincinnati contractor makes technical issues such as refrigerant leaks, condenser coil faults, or compressor malfunction go unnoticed.

This causes the air conditioner to underperform and fail to meet your home’s cooling needs, so ensure that you schedule professional AC maintenance at least once a year.


The best way to improve the efficiency of your AC is by scheduling professional maintenance. This allows you to stay ahead of the above issues that prevent the air conditioner from cooling your home.

Home Base Project Team
Home Base Project Team
At The Home Base Project, we offer practical, real-life tips and inspiration about DIY, decorating and gardening. The Home Base Project provide the best information about home renovation and design, connecting home design enthusiasts and home professionals across the world.