As a homeowner if you are investing in a new HVAC system, you should look for an installer that completes the following five steps. They may be a little more expensive in the short-term, but protects your home and family.
The installer should double-check the equipment and ductwork sizing of the new system to make sure it is the properly sized to fit your home.
The installer should be licensed, insured, and should take the time to pull a permit, which will require a 3rd party to inspect their work.
The installer should follow manufactured recommended practices during the installation. Such as verifying the proper electrical, venting, refrigeration line practices, and condensate system design and installation.
The installer should properly start-up and test the equipment to make sure it is functioning per design and operates in accordance with the manufacturer's instructions.
Finally, the installer should register the equipment with the manufacturer and close out the job with the final inspections to validate that the work is completed per code.
All of these steps take time to do properly; but in the end you will have the right-size system, which is properly installed and will provide years of comfort and an energy-efficient operation. It is a smart investment to have a qualified company that can correctly install your new system.