1. Clean or replace the filter: A dirty filter can block airflow, reducing the system’s efficiency and its ability to cool the air. If you haven’t cleaned or replaced the filter recently, try doing this first.
2. Inspect the condenser coils: These are located in the outdoor unit of your AC system and can become coated in dust, dirt, and other debris, which can reduce the AC system’s ability to cool your home. If they look dirty, turn off the power to the AC and clean them using a hose. If they’re heavily coated in debris, you may want to call in a professional.
3. Check the evaporator coils: If the evaporator coils are dirty or frozen over, they won’t be able to absorb heat effectively, resulting in less cool air being produced. You may need a professional to clean or defrost the coils.
4. Look for blocked vents: Ensure all the vents in your home are open and clear of blockages like furniture or drapes.
5. Check the thermostat: Make sure your thermostat is set to the correct temperature and is functioning properly. If it’s not, you may need to replace it.
6. Inspect the ductwork: If you can access any part of your ductwork, check for leaks or gaps where cool air might be escaping. Seal any leaks with duct tape.
7. Evaluate the refrigerant levels: If your AC system is low on refrigerant, it won’t be able to cool air effectively. A professional will need to check and refill this.
8. Ensure proper maintenance: Regular maintenance is key to keeping your air conditioner working efficiently. A professional can check the entire system, including the belt and motor.

Remember, if your system is old, it may not be as efficient as more modern systems. Also, if it’s too small for the area you’re trying to cool, it may not be able to keep up with the demand. In both these cases, you might consider upgrading to a new system.