Residential Heating System Upgrade Towards a Net-Zero Energy Building: A Case Study in California

As global environmental concerns escalate, achieving net-zero energy buildings and advancing decarbonization efforts have become critical strategies for fostering sustainable urban development. The selection of a heating system in a building is crucial in reducing energy consumption and carbon dioxide (CO2) emissions. While fossil-fueled heating systems such as furnaces are still in consumer demand, there are alternative options like heat pumps that can support sustainability goals. This paper presents a case study of a residential building in the Bay Area of California, United States, with a resistant heating system that was renovated with a central heating system and a solar system to achieve the net-zero energy goal. The heating system ran in furnace mode during the first heating season while it was in heat pump mode in the following two heating seasons. The energy consumption in the building and subsequent CO2 emissions were compared for these two heating systems based on the metering data. The results show that the heat pump consumed up to 25.5% less energy and emitted up to 22.3% less CO₂ than the furnace. The data also proved that the project could achieve its net-zero energy goal. This study aims to encourage homeowners, designers, and contractors to consider sustainable building system options that result in less CO2 emissions with potential savings in energy consumption by providing a real-world example in the residential building sector.