Articles
From Oil to All-Electric: My 1950 Cape Cod Journey
In 2022, a 1950 Cape Cod home in Connecticut was operating with a 77 percent efficient oil boiler, no cooling, and an Energy Use Intensity (EUI) of 95 kBTU per square foot per year, placing it in the bottom 25 percent of comparable homes. Rather than relying on modeled assumptions, the retrofit was designed using measured performance data, including real-time fuel consumption during peak winter conditions.
The upgrade followed a staged approach. Envelope improvements, including insulation and duct sealing, reduced EUI from 95 to 56. A cold-climate air-to-water heat pump was then installed and sized to a measured peak load of approximately 60,000 BTU per hour. The system provides space heating, cooling, domestic hot water, and snowmelt from a single plant.
Post-installation performance was continuously monitored using a custom BTU metering system and circuit-level energy tracking. After system tuning, including outdoor reset controls and buffer optimization, the home achieved an EUI of 21 and a measured seasonal COP of 3.6. Weather-normalized heating costs decreased by approximately 40 percent compared to oil, while expanding system capability.
This case demonstrates that significant energy reductions in existing homes are achievable through measured data, load reduction, and properly sized electrification systems.