Reference Standard 90.1
(2) Reference Standard 90.1 The term “Reference Standard 90.1” means, with respect to any property, the more recent of— (A) Standard 90.1-2007 published by the American Society of Heating, Refrigerating, and Air Conditioning Engineers and the Illuminating Engineering Society of North America, or (B) the most recent Standard 90.1 published by the American Society of Heating, Refrigerating, and Air Conditioning Engineers and the Illuminating Engineering Society of North America for which the Department of Energy has issued a final determination and which has been affirmed by the Secretary, after consultation with the Secretary of Energy, for purposes of this section not later than the date that is 4 years before the date such property is placed in service.