ASHRAE 1478: Measuring Airtightness of Mid- and High-Rise Non-Residential Buildings PDF

ASHRAE 1478 is a research project designed to measure enclosure airtightness of mid- and high-rise buildings in the UnitedStates. Data were collected from 16 non-residential buildings in climate zones 2–7 constructed since the year 2000. The datasetincludes buildings with no particular attention to making the building airtight, buildings where some attention was given toairtightness, and buildings where extensive attention was paid to airtightness. Some of the buildings were designed to be sustainable(e.g., receiving LEED status). Buildings ranged from four to fourteen stories. A fan pressure testing protocol based on ASTME779 was developed by the project team. A number of issues in using E779 to test large building were identified, discussed, andaddressed. Building airtightness was reported inCFMper square foot of above grade enclosure at a 75 pascal induced shell pressuredifference and CFM per square foot of complete enclosure (including slab and below grade conditioned space walls). Theresults range from 0.06 cfm 75/ft² to 0.75 cfm 75/ft² of complete enclosure (1.10 m³/h/m² to 13.7 m³/h/m²). Major air leakagesites were identified in the course of testing. Air leakage throughHVACrelated penetrations was measured in a subset of the buildings.Factors that are associated with the most airtight enclosures include air-barrier continuity detailed in construction documentsand precast concrete panel construction. Damper air leakage turned out to be a significant portion of the total enclosureair leakage in some of the buildings. The significance of air leakage by HVAC systems is reviewed in relation to building air tightness.

Presented at Thermal Performance of Exterior Envelopes of Whole Buildings XII, December 2013