Car Aircon Regas: Everything You Need to Know When your car air conditioner is not cooling as well as it used to, low refrigerant could be one of the reasons. Regassing a car aircon involves removing the old refrigerant and replacing it with the correct amount of fresh refrigerant. This can help restore cooling performance when low refrigerant is affecting the system. Over time, refrigerant levels can become too low and affect how well the air conditioner cools the cabin. A car aircon regas restores