This investigation studied air conditioning systems installed in newly constructed homes in Phoenix, Arizona. The air flow and charge of the air conditioning units, the leakage of the ducts and building shell in a sample of 28 systems were measured. The investigation found that the newly constructed homes have substantial deficiencies in their air conditioning systems, similar to those found in studies from other parts of the country. Improvements can be made to provide lower energy use and reduced peak electrical demand while improving occupant comfort and satisfaction. Air flow across the inside coil averaged 14% below specification and only 18% of the units were correctly charged. New homes in this sample were very airtight, with up to 82% not meeting ASHRAE ventilation standards with the windows closed. The measured supply duct leakage averaged 9% of the air handler flow. Return leakage was less, on the average, at 5% of flow. Four systems with platform returns had very high return leakage. These results are supported by extensive information gathered in this project as well as data from projects in other climates.

Units: Dual

KEYWORDS: year 1997, Measuring, unit air conditioners, USA, air conditioning, new buildings, housing, air flow rate, leaking, air tightness, ducts, buildings, performance, energy consumption, electricity consumption, ventilation, air infiltration