Retrofitting Arleta Manor: 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

September 2019. From 2015-2018, TAF partnered with Toronto Community Housing to undertake retrofits in seven buildings on three sites. This case study looks at one of those sites, Arleta Manor. Arleta Manor is a two-building seniors residential complex in North York constructed in 1972 containing 372 apartments.

One notable aspect of the retrofit: This was the first demonstration of gas absorption heat pump technology for multi-residential domestic hot water heating in the cold Canadian climate. In the first year of operation, the heat pumps saved 10,000 m3 of natural gas and 19 tonnes of carbon emissions compared to the pre-retrofit heating system.

Key outcomes at Arleta Manor:

30 per cent reduction in carbon emissions
Higher than projected utility cost savings
Significantly improved indoor environmental quality

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.