determined under section 1(c)(2) for the calendar year in which the taxable year begins, determined by substituting calendar year 2017 for calendar year 2016 in subparagraph (A)(ii) thereof. (B) Rounding The amount of any increase under subparagraph (A) shall be rounded to the nearest multiple of $10,000 ($100,000 in the case of the $5,000,000 and $20,000,000 amounts in subsection (b)). . (b) Application to qualified energy efficient heating and air-conditioning property (1) In general Section 179(f)(2) is amended by striking and at the end of subparagraph (B), by striking the period at the end of subparagraph (C) and inserting , and , and by adding at the end the following new subparagraph: (D) qualified energy efficient heating and air-conditioning property. . (2) Qualified energy efficient heating and air-conditioning property Section 179(f) is amended by adding at the end the following new paragraph: (3) Qualified energy efficient heating and air-conditioning property For purposes of this subsection— (A) In general The term qualified energy efficient heating and air-conditioning property means any section 1250 property— (i) with respect to which depreciation (or amortization in lieu of depreciation) is allowable, (ii) which is installed as part of a building’s heating, cooling, ventilation, or hot water system, and (iii) which is within the scope of Standard 90.1–2007 or any successor standard. (B) Standard 90.1–2007 The term Standard 90.1–2007 means Standard 90.1–2007 of the American Society of Heating, Refrigerating and Air-Conditioning Engineers and the Illuminating Engineering Society of North America (as in effect on the day before the date of the adoption of Standard 90.1–2010 of such Societies). . (c) Effective date (1) Increased dollar limitations The amendments made by subsection (a) shall apply to taxable years beginning after December 31, 2017. (2) Application to qualified energy efficient heating and air-conditioning property The amendments made by subsection (b) shall apply to property acquired