Report Released: Commercial Condensing Boiler Optimization

Apr 14, 2017

condensing-boilers-(1).jpgThe availability and high market penetration of high efficiency condensing boilers provides significant, cost-effective savings potential for commercial building owners and Conservation Improvement Programs (CIP). However, the actual savings achieved in the buildings is less clear.

The sensitivity of condensing boiler efficiency to field operating conditions is widely recognized in the industry, but information about the impact of actual field operating conditions in Minnesota buildings has generally been limited to only varied anecdotal sources. The Center for Energy and Environment undertook this field research study in order to gain more insight into the performance under real operating conditions of commercial condensing boilers, and to identify methods for utility programs to improve energy efficiency.

On average the observed condensing boilers achieved just over half of the expected savings. The average boiler plant efficiency of 87.2% is 6.8 percentage points below the average rated efficiency of the condensing boilers.

Researchers did find that all of the sites have low-cost opportunities to improve boiler efficiency, and at some sites the potential is very large. The best savings measures, in order of savings, are:

  • Improved outdoor reset control
  • Preventing or correcting sub-optimal piping
  • Improved staging control
  • Improved burner tuning

About 80% of the identified efficiency improvements can be achieved with a simple cost-payback period under five years.

This project was supported in part by a grant from the Minnesota Department of Commerce, Division of Energy Resources through the Conservation Applied Research and Development (CARD) program. The project was co-funded by CEE in support of its nonprofit mission to advance research, knowledge dissemination, and program design in the field of energy efficiency.

Related Links
Full report: Commercial Condensing Boiler Optimization
More about this study on the project page