An independent study by Prism Engineering Ltd* revealed that installing a high-efficiency boiler for space and water heating achieves an average energy savings of 16 per cent** overall. For multi-unit residential buildings (MURBs), the average savings is even higher, 18 per cent.
This study was based on data from 135 participants in the Efficient Boiler Program (EBP). As well as 85 MURBs, the study gathered data from 14 office buildings, 13 schools and 23 other types of buildings, resulting in a significant insight into the actual energy savings that can be achieved by installing a high-efficiency boiler for space and water heating.
Input data
Data provided by FortisBC included:
- pre and post installation billing analysis of customers’ natural gas consumption
- general building information (type, sector, heated floor area, physical location)
- date of high efficiency boiler installation
- type of boiler installed (make, model, capacity and efficiency)
- telephone survey to collect site information on existing mechanical systems including any changes and operation practices to gain a better understanding of the individual savings
Analysis
The scope of work for the study included:
- evaluating the energy savings, including total energy saved in gigajoules (GJ), energy saved in GJ per site (along with the average savings in per cent), actual versus projected savings and multi-year savings trends
- analysis of the data by efficiency levels such as non-condensing versus condensing boilers
- analysis of the data by building type (MURB, office, school and other)
- a review of the boiler sizing (pre and post retrofit) to determine the percentage oversized
- assessment of system changes (e.g. piping, pumping) that may have occurred at the same time as the boiler installation
You can achieve savings too
Across all four building types the average savings was 16 per cent. However, participants who installed a condensing high-efficiency boiler achieved savings above average, while those who installed near-condensing boilers showed savings below average.
Participants who also did a comprehensive retrofit of the building automation system and/or redesign of the HVAC system achieved higher savings than sites that replaced the boiler only.
Although the overall savings percentage was close to our predictions, the range of results was significant. The study shows that savings depend on the building type, retrofitted boiler efficiency, other gas loads not impacted by the retrofit, and whether or not other energy management measures were implemented along with the boiler replacement.
Conclusion
All four building types experienced positive energy savings, with MURBs averaging 18 per cent, office buildings 13, schools 20 and others, at nine per cent. The lower average for others is likely due to the more varied range of building types in this group.
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*The report was prepared by Prism Engineering Limited for FortisBC. The material in it reflects FortisBC’s professional judgment in light of the information available at the time of preparation. Without expressed written permission, any use which a third party makes of this report, or any reliance on or decisions to be made based on it, are the responsibility of such third parties.
Prism Engineering Limited accepts no responsibility for damages, if any, suffered by any third party as a result of decisions made or actions based on this report.
**FortisBC makes no representations or warranties regarding energy savings. Actual savings may vary, and are dependent upon boiler selection, end use application and the quality of the installation among other factors.