To earn the Most Efficient designation, a manufacturer must be an ENERGY STAR partner in good standing and have their product's performance certified with an EPA-recognized Certification Body. If the product meets the applicable recognition criteria for a Most Efficient product, for most categories, they will be highlighted automatically on the ENERGY STAR Most Efficient web page. Additional information must be submitted for central air conditioners, air source heat pumps, geothermal heat pumps, ductless air conditioners and heat pumps, furnaces, and windows. When EPA has confirmed a product's eligibility for recognition, the Most Efficient designation will be provided, along with Most Efficient designation use guidelines.