Firstly, keep in mind that installation quality is always the most important thing for residential HVAC project. So never sacrifice contractor quality for lower price.
Secondly, remember to look up the latest tax credit and rebates as we talked above.
Thirdly, ask for at least 3 bids before you make the decision. You can click here to get 3 free estimates for your local contractor, and this estimate already takes rebates and tax credit into consideration and filter unqualified contractors automatically.