Danette O'Neal, PhD

Through 2014, the Feds allow a suite of energy tax credits for heating and cooling systems and related energy-efficiency improvements.
The basics:
Lifetime credit max of 10% of costs, up to $500 for all energy improvements combined.
If you got $500 or more back during 2009-2010, you’re done.
File IRS Form 5695 with your returns. This can be tricky, so pay attention to the details.
You must have installed a relevant heating and cooling system by Dec. 31, 2014.
Save manufacture certifications and receipts in case you need them for filing.

Although there is a $500 overall ceiling, some improvements have individual limits below $500:
$50 for any advanced main air-circulating fan.
$150 for any qualified natural gas, propane, or oil furnace or hot water boiler.
$300 for any qualified item of energy-efficient building property, as specified by the IRS. In previous guidance, this category included certain approved electric and geothermal heat pumps, central air conditioning systems, and natural gas, propane, or oil water heaters.

The Energy Star site has guidelines on what heating and cooling systems are covered. It’s your safest bet for information on which kinds of systems and individual products get you the credit.

Don’t rely solely on contractors who may not know the details of the energy tax credit program or who promise their products will get the credit in order to make a sale. (HouseLogic)