Energy Efficiency Impact
in Multi-Unit Residential Buildings BC Housing, British Columbia. Canada.
A pilot study of 12 existing multi-unit residential buildings was conducted by Morrison Hershfield for BC Housing in 2018 and 2019, testing the impact of EndoTherm. Morrison Hershfield are one of the largest engineering and management consulting services in the areas of energy and building technologies in Canada.
Space heating accounts for between 67% and 84% of the total natural gas consumption for the buildings in this study. In British Columbia, space heating with natural gas represents the largest source of greenhouse gas (GHG) emissions from buildings.
BC Housing currently has a GHG emissions reduction target of 50% from 2005 levels by 2030, and 80% by 2050.
Analysis of the efficacy of EndoTherm was done by comparing whole-building natural gas use (daily and monthly consumption data as available) from before and after the installation, normalized for weather.
The 12 buildings included in the study were selected to represent common residential building types in the lower mainland, and all use hydronic boiler-based heating systems. Out of these 12 buildings, 10 buildings are two-four storey wood-framed low to mid rise construction and 2 buildings are concrete high-rises.
Buildings that had not undergone recent retrofits that would impact heating loads were specifically selected. Retrofits such as envelope upgrades or changes to mechanical systems would make it impossible to establish a reliable baseline of existing building performance.
On average, the 12 buildings analyzed show greater than 5% savings in natural gas for space heating compared with the predicted value based on previous years and test period weather data.
While most of the 12 buildings included in the pilot study showed savings, and overall the pilot study indicated savings were expected, some buildings showed an increase in natural gas use compared with predicted results. While those increases, such as the 28% increase at building seen in Figure 1, are attributable to factors other than EndoTherm, this data does indicate that there may not be measurable savings in all cases due to other factors that could be impacting energy consumption in a more significant manner.
Using the energy consumption during the baseline years, an energy model was produced to predict the expected energy consumption of each building. The left side of the Figure 2 shows the predicted versus actual energy consumption based on weather normalized data for one example building prior to EndoTherm addition. The right side shows the predicted weather normalized energy use versus the actual use following the addition of EndoTherm into the system. The figure shows clear energy savings compared with the predicted value.
|Total Cash Saving:
$11,300 – $19,000 (CAD)
|Total CO2 Saving:
70 – 118 tonnes
Based on the heating gas savings range of 5 – 8.4%, EndoTherm has a simple payback period in the range of 2.7 – 4.5 years. Beyond this period, EndoTherm will continue to result in reduced natural gas consumption and the associated energy cost and GHG savings.
For more information on this case study visit BC Housing
BC Housing develops, manages and administers a wide range of subsidized housing options across the province. They also license residential builders, administer owner builder authorizations and carry out research and education that benefits the residential construction industry, consumers and the affordable housing sector.
BC Housings vision is to serve as a trusted leader and partner in sustainable solutions for British Columbians.