If your air conditioner is not producing cold air, it could be low on refrigerant.
The air conditioner will be low on refrigerant for two reasons. Either it was undercharged during installation, or the air conditioner is leaking refrigerant.
If your air conditioner is leaking refrigerant, merely adding refrigerant is not going to solve the problem. An air conditioning repair service will need to be contacted, they will fix the leak, test the repaired leak and then recharge the system with the correct amount of refrigerant. This is not a job you want to try, refrigerants are highly toxic and should be handled by trained and certified technicians.
The air conditioner works at its best efficiency when the amount of refrigerant matches exactly to the manufacturer’s specifications. If it is undercharged or overcharged the performance of the air conditioner will be affected and will cause problems overtime.