Research Project Summary Information
Uncontrolled Air Flows in Commercial Buildings :Uncontrolled Air Flows in Buildings(ST6770-1)
CDH Energy Corporation
The Florida Solar Energy Center (FSEC) completed a study of uncontrolled air flows (UAFs) in small commercial buildings. This study revealed that in Florida (1) the envelopes of small commercial buildings are leakier than single-family residences, (2) the duct systems in small commercial buildings are roughly three times leakier than in single-family residences, and (3) suspended ceilings in small commercial buildings are approximately ten times leakier than gypsum board ceilings. While buildings in New York are constructed differently and exposed to a colder climate, it is believed that they exhibit similar air flow characteristics to those in Florida. Even so, there is no quantitative data to support this belief or document the potential benefits for reducing UAFs in New York buildings.
The Contractor will: quantify the characteristics UAFs in 25 small commercial New York buildings, test typical wall constructions in Syracuse University's Thermal and Air Quality Research Facility to validate data collected from the 25 buildings, test typical ceiling constructions and duct assemblies in FSEC's Building Science Laboratory to quantify whole-building air flow effects under controlled conditions, demonstrate and evaluate techniques for reducing UAFs in three small commercial New York buildings, use the collected results to validate existing computer analysis programs that predict air movements and energy usages within buildings ,and disseminate project results to the building community through training seminars.
This project produced information on the energy performance of small commercial buildings in New York State that previously had not existed. This information may aid architects and engineers in designing more energy efficient buildings. Seminars were held in Albany and Syracuse to disseminate the results of this work to architects and engineers.
Field testing in 25 small commercial buildings found that, on average, New York building were tighter than Florida buildings. Duct leakage in New York buildings was found be on par with buildings in other parts of the country. Retrofitting of three New York buildings found that uncontrolled air flows could be reduced with relatively little expense.
Laboratory testing at Syracuse University revealed that steel studs around windows can be a significant source of thermal bridging. Steel studded walls were also determined to pose a greater risk of moisture accumulation in cavity insulation due to thermal bridging. The thermal mass effect of masonry walls was found to be small for tested conditions.
Whole building testing at Florida Solar Energy Center’s BSL systematically evaluated the air tightness, infiltration, relative humidity, energy, and peak demand impacts of duct leakage during the cooling seasons with various attic and ceiling space configurations. The two primary independent variables were the amount of attic venting and the amount of duct leakage. Peak cooling demand increased by 10% to 40% for the unvented attic and by 12% to 58% for the vented attic, for various duct leak configurations. While attic venting is common construction practice for commercial buildings in Florida, it is less frequently found in New York buildings.
CDH Energy Corporation
2695 Bingley Road PO Box 641
Cazenovia, NY 13035
Building Construction Methods
NYSERDA Contact Information
R&D - Buildings Research