Installing an HVAC - prep work or conditions.

This will not be a DIY job, but since I know nothing about HVAC systems I would like to know more or less what I am talking about in order to choose the right professional. Just very general information of what surroundings it is best installed in and what kind of prep needs to be done before hand.

Greetings Russel welcome to the Forum.

First...
Check out the type and size of the equipment that will be installed.
Consumer Reports.

Next...
Check out the Installer,
Better Business Bureau.

Then ask/and get in writing,
Will he submit the job for Permits.
Will he provide Electrical and Mechanical services thru his company, if not who, and check them out via BBB.
What is the time-line on the Job.
What is the length of warranty for it.

Have a good Day !
S.W.