Hi: I am looking to replace my HVAC and duct work. I requested an estimate from a reputable and authorized Lennox dealer. The guy shows up and he presents me a one page Manual J calculation (report?) for my house. He's never been to my house but i suspect he was able to get information about my residence either from public records or google earth. I say Google Earth because he knew which windows were facing south, etc.
All the other contractors who came to give estimates said they do the Manual J after they get the job to fine tune the exact tonage. All of themn said i needed a 3 ton system
Question: Is it possible to do a Manual J without really looking at my house? Is this the norm or unusual?