The difficult part is to find a good HVAC contractor. When we asked
contractors about setting central cooling in my house, we got many
different advices, and we were not in the position to know which one
was the right one. The same thing happened when we ask contractors to
fix the roof in my house. We got confused. Hopefully, there is a good
trick to tell which one is good.

There must be a good way to tell. I believe each trade has a way to
locate a good contractor. For example, if someone wants to look for a
doctor, one good way is to ask the nurse. Nurses know _exactly_ which
doctors are good and which ones to avoid. I assume that there must be
a similar trick in HVAC industry to locate a good contractor. I really
doubt that asking our friends or neighbors will be any help because
they probably know even less. This is just like this is not a good
idea to ask a patient to recommend a doctor. A patient will rate how
the doctor "talks" more than anything; hence, he will always give a
good rating to a doctor who is probably more like a salesman than a
doctor.

Jay Chan