As part of the fiscal cliff deal that was passed in Congress earlier this year, homeowners may claim up to a $500 federal tax credit for installed costs of a qualified energy efficient retrofit improvement to their HVAC system. A 95% efficient gas furnace ($150) with a variable speed blower ($50) and/or 16 SEER / 13 EER air conditioner ($300) qualifies. This tax credit was made retroactive to January 1, 2012 and runs through December 31, 2013. Also, for homeowners in the market to replace their HVAC equipment, residential code in Ohio now requires you to install or have in place a CO detector.