When you are on the energy efficient credit section, the first screen will only ask you about alternative energy sources, such as solar and geothermal power. Click next or continue, and the second screen will ask about insulation, air conditioning and the furnace. The air-conditioning and the furnace are entered on separate lines. The air conditioner is eligible for up to $300, and I believe the furnace is only eligible for up to $150. The credit is 10% of the amount of the appliance. If you are audited, you will need to show something that supports how you allocated the cost between the furnace and the air conditioner. Ideally, your contractor will give you a specific breakdown.
