Which of the following is a potential source of water conservation in commercial buildings?

High-efficiency appliances are considered a significant source of water conservation in commercial buildings because they are specifically designed to use less water while maintaining or improving performance. For example, high-efficiency dishwashers and washing machines consume less water per cycle compared to their standard counterparts, leading to substantial water savings over time. This is particularly important in commercial settings where water usage can be substantial, such as in restaurants, hotels, and laundromats.

In contrast, extra-large toilets typically use more water per flush, which does not support water conservation goals. Traditional shower heads often have higher flow rates than modern, water-efficient designs, contributing to greater water usage. Fixed aerators can be more efficient but may not provide the same level of savings as high-efficiency appliances, which are engineered for optimal water savings across multiple applications. Thus, high-efficiency appliances stand out as a leading option for enhancing water efficiency in commercial buildings.