March 3, 2003—A unique cooling and air distribution system demonstrated at a Florida elementary school by researchers at the Florida Solar Energy Center (FSEC), a research institute of the University of Central Florida, has received a Technology Award Honorable Mention from the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE).
The system was designed to address high humidity levels and indoor air quality problems often found in schools, especially in humid climates, caused by large ventilation air requirements and small classroom size. A dual path, low-temperature air distribution system, in which the outdoor ventilation air and the recirculation air streams are conditioned separately with their own cooling and dehumidification coils, was installed in the school.
The system is enhanced by a thermal energy storage system that takes advantage of electric utility time-of-use rates by making ice during nighttime hours and using that stored energy to meet the school’s cooling loads during the utility peak periods in the daytime.
Results showed the system performed well, maintaining indoor relative humidity levels more than 10 percent lower than in comparable schools, yet the school’s energy use was only 4 percent higher than for a similar school with a conventional air distribution system and without thermal storage.
This small energy difference, however, disappeared when differences in occupancy levels between the schools were taken into account. By shifting about 300 KW of electric demand from the utility’s on-peak period and using the utility’s time-of-use rate schedule, the school with the new system saves 22 percent on energy costs.
For more information on the project, contact Don Shirey at the Florida Solar Energy Center; 321/638-1451.
