If your heating or cooling system begins to perform poorly, your natural assumption may be that the system itself needs repair, or even replacement. However, the reason your systems are running so inefficiently could actually be due to the air ducts.
Poor duct sealing is actually a fairly common issue in the HVAC industry. This is due partly because individuals who lack HVAC experience install their own air ducts during home construction, or hire an unlicensed professional to do so. Air pressure in the ducts over time can also cause ductwork to develop cracks and holes, but professional duct installation will reduce this risk.