Mechanical Insulation Installation Incentive Act of 2011

Mechanical Insulation Installation Incentive Act of 2011 - Amends the Internal Revenue Code to allow an additional tax deduction for the cost of installing mechanical insulation property. Limits the amount of such deduction to the lesser of 30% or the reduction in energy loss from the installed mechanical insulation property compared to property that meets the minimum requirements of American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standard 90.1-2007. Allows the cost of replacing mechanical insulation property to be treated as a deductible business expense in the current taxable year.

Defines "mechanical insulation property" as insulation materials, facings, and accessory products: (1) placed in service in connection with a mechanical system which is located in the United States and of a character subject to an allowance for depreciation; and (2) utilized for thermal, acoustical, and personnel safety 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.

Allows a tax deduction for capital expenditures related to mechanical insulation property.