Burton Air Conditioning Hold full company F-gas certification. All of our engineers are now CITY & GUILDS qualified and hold F-gas certification, which means we can legally work on your system. So what does this mean? The Refcom Register of Companies Competent to Manage Refrigerants (now Refcom Elite) was set up in 1994 in response to atmospheric damage caused by certain refrigerant gases. Since then the Register has evolved to cover fluorinated refrigerant gases which if rel