I think a new HVAC unit would count as a major renovation. It is not specifically listed but I think this could be considered a major renovation item. I think that the cost of the tax for the materials is likely deductible, but not the cost of installation, assuming you did not do it yourself.
IRS guidance is below:
General Sales Tax You Paid on Specified Additional Items
Enter in the box provided any state and local general sales taxes paid on the following specified items. If you moved during the year, include the total for the year in that box.
A motor vehicle (including a car, motorcycle, motor home, recreational vehicle, sport utility vehicle, truck, van, and off-road vehicle). Also include any state and local general sales taxes paid for a leased motor vehicle. If the state sales tax rate on these items is higher than the general sales tax rate, include only the amount of tax you would have paid at the general sales tax rate.
An aircraft or boat, if the tax rate was the same as the general sales tax rate.
A home (including a mobile home or prefabricated home) or substantial addition to or major renovation of a home, but only if the tax rate was the same as the general sales tax rate and any of the following applies.
Your state or locality imposes a general sales tax directly on the sale of a home or on the cost of a substantial addition or major renovation.
You purchased the materials to build a home or substantial addition or to perform a major renovation and paid the sales tax directly.
Under your state law, your contractor is considered your agent in the construction of the home or substantial addition or the performance of a major renovation. The contract must state that the contractor is authorized to act in your name and must follow your directions on construction decisions. In this case, you will be considered to have purchased any items subject to a sales tax and to have paid the sales tax directly.
... View more