TAF recently completed a comprehensive study linking energy efficiency retrofits to improved indoor environmental quality (IEQ). For those who have been following the TowerWise program closely, you will know that we have been taking on the challenge of IEQ since 2014.
With the support of many project partners including Toronto Community Housing, the University of Toronto, and Health Canada, we began to investigate the benefits that energy efficiency retrofits could have on resident health and comfort. In May 2015 we began in what would become a three-year project examining pre-and-post retrofit conditions in seven multi-residential buildings.
Reducing over-heating saves energy, creates a more comfortable environment, and lowers utility bills
- PROBLEM: Over-heating in the winter and shoulder seasons was prevalent across the seven buildings, typical of the Toronto multi-unit residential building stock.
- TAF ACTION: Installed right-sized condensing boilers and introduced smart thermostats to provide suite-level control.
- IEQ IMPROVEMENT: 54 per cent reduction in residents feeling “too hot”, and 39 per cent less window opening in the winter.
Improving ventilation reduces drafts and odour infiltration
- PROBLEM: Fresh air supply provided to the buildings was 43-50 per cent below modern code standards.
- TAF ACTION: Ventilation systems were replaced with high efficiency equipment, ventilation ducts were cleaned.
- IEQ IMPROVEMENT: Residents reported a 31 per cent reduction in odour infiltration from neighbouring suites, 35 per cent reduction in reported condensation issues in winter, and an 18 per cent reduction in draftiness.
There’s a strong business case for improving IEQ
Many energy efficiency measures inherently work to improve resident comfort by increasing efficiency and reducing waste energy. Often in older buildings the most significant IEQ improvements will come from upgrading the systems that waste the most energy. In terms of the overall project performance of the seven buildings involved in this study, TAF expects the energy and water retrofit measures installed will lead to a 364 per cent return on investment (over a 25-year project lifetime) and annual utility savings of $502,000.
Big lesson? Act early
The key to seeing savings as well as improved tenant comfort is to integrate IEQ goals early in retrofit planning and to involve residents, to ensure the opportunities for multiple benefits are maximized along the way.
TowerWise is moving on with its latest phase, Accelerating Deep Energy Retrofits, where we are working to develop the tools and resources needed to achieve 40 per cent energy savings in the multi-residential sector. IEQ remains an important goal as we continue to demonstrate energy efficiency retrofits in the GTHA.