Introduction: The Importance of Energy Management in Historical Buildings

Historical buildings present unique challenges and opportunities in energy management, particularly in the context of renovations that aim to preserve their heritage while enhancing their functionality. In the United States, a significant portion of energy consumption—up to 50%—is dedicated to space conditioning, including heating, cooling, and ventilation. This high level of consumption underscores the importance of finding cost-effective, energy-efficient solutions that not only reduce expenses but also contribute to environmental sustainability.

Renovation Impact: A Case Study of the DC House

The focus of this discussion is a two-story residential home from the 1920s, located in West Lafayette, Indiana, and protected by the city's historical preservation committee. This home, referred to as the DC House, has undergone several renovations aimed at improving its energy efficiency. These modifications included the installation of variable-speed heat pumps and the integration of a novel DC-based nanogrid architecture, among other changes.

General contractors and builders can learn from this case study as it highlights the process and outcomes of integrating modern technology into historic structures without compromising their integrity. The research was conducted over a two-year period, analyzing energy usage before and after each renovation phase. This longitudinal study provides valuable insights into the effectiveness of each modification under dynamic environmental conditions.

Methodological Approach to Energy Efficiency

The methodology adopted for the DC House renovations involved a baseline comparison of energy consumption against improvements made during each configuration period. This comparison was critical to assess the effectiveness of each renovation in reducing energy usage. The researchers employed heating degree day (HDD) and cooling degree day (CDD) metrics, standard in the industry, to measure the building's energy efficiency over time.

One innovative aspect of the project was the retrofitting of appliances and systems from alternating current (AC) to direct current (DC), which is more energy-efficient. This transition not only supports energy conservation but also enhances the home's capability to integrate renewable energy sources like solar and wind power.

Results: Enhancements and Energy Savings

The results of the DC House project are compelling, showing significant improvements in energy efficiency and consumption. Post-renovation, the house achieved a 31.3% improvement in cooling system effectiveness and a 2.38% increase in heating efficiency. These figures illustrate the potential energy savings and environmental benefits of renovating historical buildings using modern technology.

For general contractors, these outcomes emphasize the importance of adopting and promoting energy-efficient solutions in building renovations. Not only do such renovations offer a return on investment through reduced energy costs, but they also play a critical role in the broader context of sustainable development.

Conclusion: The Role of General Contractors in Promoting Sustainability

General contractors play a pivotal role in the renovation of historical buildings, especially when it comes to incorporating energy-efficient technologies. The DC House case study serves as a blueprint for how historical homes can be retrofitted to meet contemporary energy standards while preserving their architectural integrity.

This project not only benefits the homeowners but also sets a precedent for future renovations, demonstrating that historical buildings can indeed be part of our sustainable future. General contractors are at the forefront of this transformation, equipped with the knowledge and tools to make significant impacts on energy consumption and efficiency in the building sector.

Acknowledgments

The project received support from the Center for High Performance Building and involved numerous vendors who contributed to the data collection and analysis, demonstrating the collaborative effort required for such innovative renovations.

This case study not only provides a roadmap for other similar projects but also reinforces the importance of detailed, methodical approaches to building renovations that prioritize energy efficiency and sustainability.

Source: Ore, Jonathan P., et al. "Evaluation of Energy Consumption and Efficiency in a Historical Residential Home Before and After Building Renovations." ASHRAE Transactions, vol. 127, no. 1, Jan. 2021, pp. 110+