A central air conditioner works by using a chemical refrigerant to cool the air that is pulled through it. While an air conditioner is a sealed unit, you stil may need to recharge the refrigerant from time to time. Here's what you should consider.
Setting a Maintenance Schedule
A central air conditioner shouldn't need to be recharged every year. However, yearly maintenance and inspection of your unit is a good idea. This will save you from being without air conditioning during hot summer months if something goes wrong. The inspection should include a report that details how well the unit is working, how much refrigerant is remaining, and any problem areas that may need attention.
Recharging the Refrigerant
The reality is, an air conditioner unit that is functioning perfectly should never need to be recharged. If the refrigerant level is decreasing, it's because there is a leak somewhere in the system that needs to be repaired. If a technician suggests just recharging the system, you are leaving yourself open to more problems down the road. If money is an issue, having your unit recharged may help you make it through the summer, but the leak will eventually need to be addressed. It's best to have the system checked for leaks every few years. This doesn't have to be part of a yearly maintenance schedule, but it's not a bad idea either.