Definition
The International Energy Conservation Code (IECC) is a model energy code published by the International Code Council (ICC) that establishes minimum efficiency standards for building envelopes, mechanical systems, and electrical systems in residential and commercial buildings. Updated every three years, the IECC drives national trends toward higher HVAC equipment efficiency and improved system performance.
HVAC Equipment Standards
The IECC specifies minimum efficiency ratings including SEER2 15 for air conditioners, HSPF2 8.5 for heat pumps, and AFUE 90 percent for furnaces in residential applications. Commercial systems must meet IEER and part-load efficiency requirements. The code also mandates duct sealing, with maximum leakage of 10 percent of system airflow after testing.
System Controls and Commissioning
The IECC requires automated controls for heating and cooling set points, thermostatic controls on electric resistance heating, and system commissioning documentation. Ventilation systems must include demand control in commercial spaces and energy recovery ventilation (ERV) in some climate zones, improving overall building energy performance.