Check out Matt Risinger's Youtube channel. He's a builder, but much of his content focuses on lowering the cost of HVAC by making sure your insulation is effect

Check out Matt Risinger's Youtube channel. He's a builder, but much of his content focuses on lowering the cost of HVAC by making sure your insulation is effective, and your building envelope is draft-free. He does cover equipment too, such as multi-zone systems.