Energy Impact of Residential Ventilation Standards in California

The California Energy Commission is considering upgrading the State energy code, known as Title 24, to require mechanical ventilation based on the requirements of ASHRAE Standard 62.2-2004, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings. These requirements will require mechanical ventilation systems to be installed in virtually all new homes, but allows for a wide variety of design solutions. These solutions, however, may have different energy costs and non-energy benefits. The authors have used a detailed simulation model to evaluate the energy impacts of common and proposed mechanical ventilation approaches for a variety of climates. These results separate the energy needed to ventilate from the energy needed to condition the ventilation air, from the energy needed to distribute and/or temper the ventilation air. The results show that exhaust systems are generally the most energy efficient method of meeting the proposed requirements, but that supply and balanced systems can provide additional non-energy benefits.