Peace of Mind
When hiring a contractor, it's important to do some research. Don't take the lowest price you find and assume that contractor will be there for service in your time of need or for any warranty repairs that may be required down the road. There a lot of "fly by night" HVAC people out there who come into the business then disappear. It's important for a homeowner to know where to look to assure that they find a reputable company that has the proper licencing, insurance and experience. It's also important to know that they have been in the industry for a period of time, which will help to assure that they will stick around for further installs and service and also that they know the proper procedures for dealing with any warranty claims you may have.
How to find a legitamate contractor.
Canadian Federation of Independent Business

Belonging to the Canadian Federation of Independent Business not only allows us a voice for small business within the federal government, but also keeps us up to date with any federal and provincial policy changes as well as provide us with training in various types of business management and customer service.
Technical Standards & Safety Authority

In Ontario, qualified HVAC contractors must be licensed with TSSA.While TSSA’s is required to enforce the Technical Standards and Safety Act and regulations, the organization promotes, informs and educates HVAC business of specific codes and regulations while monitoring and regularly inspecting equipment and jobs completed.