Several factors can cause an air conditioner to blow hot air instead of cold air. Figure out the right cause behind reduced airflow. Some of the reasons are -
Check if the thermostat setting is set to "heat" and change it back to the "cool" option.
Dirty coils and filters can limit the flow of cold air. An AC repair technician can clean these up to ensure better airflow.
Condenser coils are located outside and are prone to dust and debris. Check the condenser coil and ensure that the space is free from blockages.
Low refrigerant values cause an air conditioner to blow hot air. Get these fixed by a repair professional to increase the air quality.