my central AC is a 16-year old Trane. According to inspector, the compressor is still good and all the conditions seem to be good, except the coil is leaking. It is an old model so it uses R22. As it is so expensive to replace a new AC unit, especially it will use a crane in my case, I am thinking about having someone to replace the coil, evacuate all the freon and then re-fill it. Hope that will keep this unit work for another 5-7 years before a replacement. Is that a good idea? Is it a difficult job to replace the coil? Do HVAC contractors normally provide that type of services? Any suggestions or advice are very much appreciated! Thank you!