As 2013 draws to a close, your opportunity to collect federal tax credits for high-efficiency HVAC upgrades is drawing to an end. On Dec. 31, most of these credits will expire, making new heating and cooling equipment for your house more expensive. If you’re looking to replace your air conditioner or furnace because it’s nearing the end of its service life or because the cost of cooling your house during Fresno’s hot summers is too high, consider taking advantage of these programs: