I am shopping for a new a/c unit and have had a few estimates. Most just look at my old unit and tell me what a new one would cost to replace it.
After reading for a bit on here I guess that is not the right way to size a new unit.
So, I called around and one company is going to do a heat loss calculation first for free.
Another company I called which seems extremely knowledgeable said they will do a manual J calculation for free but they strongly recommended to do a blower door test as well and they use infrared sensors to detect hot and cold areas, check the static pressure, etc... that service runs $150
This last company is ok with doing just a manual J assessment but said that would really just be a "guess" at what I need, and to do it right I could tell they were kind of pushing the blower door test.
So, is a manual J good enough?