Retrofitting Hospital Workers Co-operative: A TowerWise Case Study

66 Walpole Ave, Toronto

Type

Town house complex, owned by Toronto Community Housing Corporation

Old System

Electric baseboard radiators, electric hot water tank, 7.6 LPF toilets

New System

LG multi-split cold climate air source heat pumps, Rheem Air Source domestic hot water heat pumps, and low flow toilet retrofit.

Partners

Toronto Community Housing Corp. | Ecosystem

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Project Details

66 Walpole Ave, Toronto: Town house complex, owned by Toronto Community Housing Corporation

Old System: Electric baseboard radiators, electric hot water tank, 7.6 LPF toilets

New System: LG multi-split cold climate air source heat pumps, Rheem Air Source domestic hot water heat pumps, and low flow toilet retrofit.

Partners: Toronto Community Housing Corp. | Ecosystem

March 2020. From 2014-2018, retrofits were undertaken at Hospital Workers Co-operative to improve the energy efficiency of the building. This case study describes the energy efficiency retrofits that achieved major reductions in utility costs and carbon emissions for this 132-apartment building.

The retrofit at Hospital Workers Co-op demonstrated that retrofits can provide a compelling return on investment while reducing environmental impacts and generating green jobs. Some of our key results:

$82,888 annual utility cost savings
157 tCO2eq emissions savings annually
37 per cent reduction in domestic hot water gas use

Gallery

Recommendations

Create a mock installation to test new technologies.

Understanding sequencing and interaction of trades, and troubleshooting issues without disrupting residents prior to a full building rollout improves results and resident satisfaction.
Enable cooling

to increase resident comfort and satisfaction, reduce peak demand, and protect against health impacts of extreme heat.
Lengthen cycle times and reduce return temperatures to allow GAHP to reach maximal steady-state efficiency.

Increase the deadband of the GAHP controller to keep it on for longer periods, installing the heat exchanger in a counterflow configuration to promote better heat transfer (and likely reduce the temperatures in the GAHP glycol loop). And, add more intelligent control to the recirculation loop such that it is not unnecessarily mixing hot water with the cold city water prior to the GAHP heat exchanger.