Energy Star is a voluntary Energy Efficiency program by the US Environmental Protection Agency (EPA). It is now managed by the EPA and DOE (Department of Energy). It certifies various products which meet or exceed high energy efficient standards. These products are listed on their Energy Star Website. These rated products always carry the Energy Star Labeling, so look for Energy Star.
The calibrated blower door test (air leakage test) allows an analysis of heat or cold air loss in a house. These leaks occur through doors, windows, vents or holes. This test can detect even small leaks which could be costing quite a bit over time and make your HVAC systems work harder