Performance of Mechanical Ventilation Systems in New U.S. Houses:

Effect of Building Airtightness and Fan Size on the Performance of Mechanical Ventilation Systems in New U.S. Houses: A Critique of ASHRAE Standard 62.2-2003 by Judy Alice Roberson Master of Science in Architecture University of California, Berkeley Professor Edward Arens, Chair As many countries have already done, the U.S. is now undergoing a transition from homes ventilated by infiltration to homes that need mechanical ventilation to provide outdoor air when windows are closed. The American Society of Heating, Refrigerating and Air-conditioning Engineers (ASHRAE) developed, and the American National Standards Institute (ANSI) recently approved, a new residential ventilation Standard 62.2-2003, which would require many new homes to have a mechanical ventilation system. However, Standard 62.2 sizes ventilation fans in such a way that the tighter the home, and the more it needs mechanical ventilation, the less likely it is to receive the minimum ventilation rate of 0.35 air-changes/hour