Lessons from a heat pump retrofit at Walpole Ave: A case study

Recommendations

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  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.

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  Enable cooling

  to increase resident comfort and satisfaction, reduce peak demand, and protect against health impacts of extreme heat.

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  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.