The federal Residential Energy Efficiency Tax Credit covers 95 percent efficient furnaces and SEER 16 rated split central air conditioning systems, as well as other efficiency measures. For high efficiency heating systems and efficient air conditioners like those with the specifications mentioned here, the tax credit covers 30 percent up to $1,500 of the cost of both equipment and installation costs.

Unfortunately, there is no cash back given for this tax credit. So, if you have no liability, a.k.a. you don’t owe money, the government will not refund you the difference. Additionally, the tax credit cannot be carried forward to future years for HVAC systems.

The only exceptions to the rule of carrying left over credit forward is for geothermal heat pumps, solar panels, solar water heaters, small wind energy systems and fuel cells.