Hi we are looking at a small rent house to buy and I noticed on the freon lines coming from the air handler and again on the outside condesor, they have flared fittings instead of brazed ones. Current owner had this unit installed 3 years ago and produced the invoice for it from a seemingly reputable ac company in town. Why would this be and is it an acceptable method? Unit works good but i was a little concerned about this. Any thoughts?