University CHP achieves efficiency
A university considered several design and upgrade alternatives for its central heating plant (CHP) to maximize energy efficiency and reduce emissions.
- Learn how to achieve maximum energy efficiency in existing central heating plants.
- Understand advantages and disadvantages of lifecycle cost analysis of different alternatives in existing heating plants.
- Understand how to reduce emissions in existing coal fire central heating plants.
Designers and managers of educational buildings continually face increased demands to improve the energy efficiency levels of their institutions. To reduce energy consumption, local and state energy codes, standards like ASHRAE Standard 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings, and guidelines like the U.S. Green Building Council LEED rating system have raised the minimum efficiency levels.
Shippensburg University (S.U.), Shippensburg, Pa., has recently implemented a “go green" initiative whose goals are reducing fossil fuel consumption and lowering energy costs throughout the campus. The university’s design and upgrade includes replacement of an aging central steam plant, which must satisfy both near-term and projected future space conditions.
Four options were devised for potential configurations for the utility systems. They compare technical and economic issues. This feature will review the characteristics of each option, economic analyses, and qualitative advantages and disadvantages.
According to a prior study, replacing the existing plant was not determined to result in a lower lifecycle cost. Moreover, additional regulations by the U.S. Environmental Protection Agency and Pennsylvania Dept. of Environmental Protection regarding air emissions of large coal-fired facilities could be expected within the lifecycle of a renovated coal-fired plant. These regulations would require costly upgrades to the emission control equipment. Current proposals by Maximum Achievable Control Technology (MACT) also require upgrades to address emissions of hazardous air pollutants. Environmental regulations are much less stringent for natural gas-fired equipment.
Central heating plant alternative designs
The existing central heating plant, shown in Figure 1, is approaching 60 years old. The large masonry (brick and concrete) structure is located near the main entrance to the campus, across from the historic portion of the campus that includes the president’s home and Old Main.
The central coal-fired heating plant generates steam that is distributed throughout the campus to heat the buildings from September through May. Each building uses a gas-fired summer boiler to meet heating requirements during the rest of the year.
The central heating plant is shut down in the summer months when minimal heating is required as it relates to keeping a large steam and condensate system in year-round operation.
A stringent study (Table1) was conducted for the design of a new heating system that would be safe, reliable, sustainable, efficient, and cost-effective in replacing the aging central steam heating system. The new system also needed to satisfy both near-term and projected future space conditioning requirements of the campus.