where do I add new Air Conditioner purchase

If this is for your own personal residence, you may claim this as an energy credit. To enter;

1. Go to the Deductions & Credits section.
2. Find the Your Home category 
3. Select Home Energy Credits and click Start/Revisit.
4. On the Energy-Saving Home Improvements screen, answer Yes and continue.
5. Follow the instructions to enter details about your improvements, such as doors, windows, furnaces, air conditioning, heat pumps, solar panels, and more.
6. TurboTax will generate Form 5695 to calculate your residential energy credits.

if you are adding it to a rental property you own, you will go to your Rental Property Summary in your return and add it in the Asset and Depreciation section of your rental summary.