By installing an HVAC system that has been designed with HVAC Manual J load calculation software, the homeowner may qualify for certain rebates and tax credits under green initiatives and programs such as EnergyStar, Built Green, and Leadership in Energy and Environmental Design (LEED). So the savings that a homeowner could potentially have by purchasing a system designed with this kind of software could be quite significant. No wonder it’s quickly becoming more and more prevalent in the HVAC industry. It’s good for the green in your wallet, but it’s also good for the green on the Earth.