From the State of Indiana website:

“As of January 1, 2009 the State of Indiana is providing a state income tax credit when certain EnergyStar rated equipment is purchased by a homeowner or small business owner.  The credit, worth as much as $100 can be used when purchasing a furnace, a water heater, central air conditioning, room air conditioner or a programmable thermostat.  Homeowners and small business owners can claim the credit on their state income tax return.”

For more information visit:  http://www.in.gov/oed/2379.htm