1. Short title This Act may be cited as the Mechanical Insulation Installation Incentive Act of 2017 . 2. Expensing of mechanical insulation property (a) In general Part VI of subchapter B of chapter 1 of the Internal Revenue Code of 1986 (relating to itemized deductions for individuals and corporations) is amended by inserting after section 179E the following new section: 179F. Mechanical insulation property (a) Treatment as expenses In addition to any other deduction in this subtitle, there shall be allowed as a deduction an amount equal to the applicable percentage of the cost of mechanical insulation property placed in service during the taxable year. (b) Applicable percentage For purposes of subsection (a)— (1) In general The term applicable percentage means the lesser of— (A) 30 percent, and (B) the reduction in energy loss (expressed as a percentage) from the installed mechanical insulation property compared to reference mechanical insulation property which meets the minimum requirements of ASHRAE standard 90.1–2007. (2) Special rule relating to maintenance In the case of mechanical insulation property placed in service as a replacement for insulation property— (A) paragraph (1)(B) shall not apply, and (B) the cost of such property shall be treated as an expense for which a deduction is allowed under section 162 instead of being treated as depreciable for purposes of the deduction provided by section 167. (c) Definitions For purposes of this section— (1) Mechanical insulation property The term mechanical insulation property means insulation materials, facings, and accessory products— (A) placed in service in connection with a mechanical system which— (i) is located in the United States, and (ii) is of a character subject to an allowance for depreciation, and (B) utilized for thermal requirements for mechanical piping and equipment, hot and cold applications, and heating, venting and air conditioning applications which can be used in a variety of facilities. (2) Cost The cost of mechanical insulation