You want to be sure that your duct and vent installation contractor is certified by the American Society of Heating, Refrigerating and Air-Conditioning Engineers. This is a professional organization that provides resources to HVAC contractors that aid in their work. This can be anything from expanded education courses to certification in new techniques.

You want to make sure you get a contractor with good references. Ask the contractor about his or her references before you ever make a hiring decision. These references can tell you everything you need to know about the contractor before you pay any money.

You will probably be asked to put down a deposit on the work before the contractor gets started. This is a standard request made by any contractor who performs work of this scale. You should not be willing to pay any more than 25 per cent as a deposit on the work. This percentage is based off of the total estimated cost of the project.