Analysis on a net-zero energy renovation of a 1920s vintage home

摘要

A 1920s vintage home was renovated with the goal of becoming net-zero energy over a 12-month period. The project was performed over a period of two years. The first phase quantified the energy profile of the house in the original state. The second phase included a deep energy retrofit to improve the thermal insulation of the building envelope and an installation of a photovoltaic-thermal solar system. The annual heating demand was reduced by almost 50% from 38,000 kWh to 19,000 kWh. Adjustments made to the annual demand considered missing occupancy during the first phase, gaps in monitoring data, and the heating system used. The thermal comfort of the home was improved by increasing the mean surface temperature of the indoor environment. The net-zero energy target was not obtained during the first year after the renovation, but the solar system did generate 60% of the site electricity consumed. The solar monitoring system was not online 100% of the year for Phase II, and additional adjustments on the HVAC controls in the house, reducing the HVAC energy consumption, will increase the percentage of site energy use being offset by solar.