For ACs to work efficiently the gas in the compressors are of utmost importance. Both window ACs and Split ACs have compressed gas which helps in efficient cooling of the rooms. The working is similar to refrigerators. There are many reasons due to which the gas may be insufficient for effective cooling. Age is one of the main factors for loss of gas in the compressors. Other factors due to which the gas maybe insufficient are leakage in the compressor, cuts or dents in the pipes which may lead to leakage. Also when the AC is being uninstalled and shifted, the gas in the compressor may leak out due to removal of pipes or bad handling during transportation.
If the AC is still under warranty, the best way to fill gas and service the AC is by the manufacturer. This is cost effective and the servicing is of very good standards. If cost is not a constraint and the requirement is for a top quality service even then it is better to go with the manufacturer based servicing. Generally though gas filling in ACs is not covered under warranty. The manufacturer will perform the root cause analysis and identify the problem but the customer may have to pay for gas filling.
The professional who will visit the house will check for the pressure in the compressor and identify how much gas is required. Post this they will fill the compressor with the required amount of gas. The professionals usually charge for the visitation and the gas charges are separate. If additional repairs are to be done, there will be extra cost for the repairs. If the gas filling is done by non authorized service professional the costs will be less and the warranty will be only for 6 months. Generally the gas lasts for less than a year and you may require to refill the gas again. In some cases it may be required to completely change the compressor for better performance and longer life of the AC.
The pressure in the compressor should be between 65 to 70 psi for a 1.5 ton ac while running to provide optimal cooling. Please ensure that the professional has filled the right amount of gas in the compressor for increased life of the compressor gas.