FLASTAR: Measured Savings of a Comprehensive Energy Retrofit in a Florida Elementary School

Abstract

This paper describes the final results for the pilot demonstration of the Florida Public Building Loan Concept. This loan program was intended to provide low cost funds to eligible public entities for upgrade of building energy systems. The site was an elementary school in Central Florida which served as the pilot project to demonstrate energy savings in public buildings similar to that achieved by the Texas LOANSTAR program (Verdict et.al., 1990). Termed FLASTAR (Florida Alliance for Saving Taxes and Resources), the study entailed the comprehensive metering of a test site to demonstrate energy savings potential. Over twenty channels of weather and submetered energy data have been collected since April 12.1995. Annual billed energy consumption for the 41.000 square foot facility was approximately 775,000 kWh (60 kBtu/ft^2) or $55,200 in the base year (1994). During the summer of 1995, replacement of aging chillers resulted in 30% reduction to cooling energy use. The second retrofit was occupancy sensor controls for classroom and office lighting which were installed in December 1995. However, post retrofit data showed that metered lighting energy use actually increased after the occupancy sensors were installed. Our data, and that of other projects. suggests that the occupancy sensor retrofit may have increased lighting on-times. Previously school personnel practiced responsible manual switching. but then came to depend on automatic control after the retrofit. The final project retrofit saw an energy management system (EMS) added in the summer of 1996. The system provided direct digital control @DC) of the school chiller, air handlers and packaged direct expansion (DX) roof-top cooling systems. The EMS equipment reduced chiller energy use by a further 16% and air handling and DX system energy consumption by 30%. The project retrofits were found to reduce overall school energy use by approximately 15% or 120.000 kWh per year. The annual energy savings totaled $4,600 at current energy prices, although the retrofits did not significantly impact facility peak load.