The tax credit makes it a little easier to do what you should do anyway: Upgrading your heating, ventilation, and air conditioning (HVAC) to energy-efficient units can cut utility costs by about 20%, or $200 annually, on average.

However, you need cash to get going—these upgrades aren’t cheap. Although prices vary, keep in mind that:

  • A high-efficiency furnace starts around $3,500, including installation, estimates Corbett Lunsford, executive director of Chicago-based Green Dream Group, an energy-efficiency and eco-consulting firm.
  • A standard furnace may cost $2,400.