The energy used to heat water can be reduced by both heating water more efficiently and by reducing hot water use. A wide variety of fixtures, such as low-flow showerheads and faucet aerators, can reduce hot water use. In a home, an older water heater can be replaced with a newer, more energy-efficient one, and the water heater and hot water pipes can be insulated to minimize heat loss. Several energy-efficient lighting options, such as compact fluorescent light bulbs, are also available. There are ways to determine how energy efficient a building really is and, if needed, what improvements can be made.
Homeowners can conduct simple energy audits on their homes or have professional audits done.
Professional energy audits are also available for commercial buildings. During the commissioning of new commercial buildings, a number of tests and adjustments can be performed to ensure that the heating, cooling, lighting, ventilation, and other mechanical systems work together effectively and efficiently. Once the systems are commissioned, their proper operation and maintenance is critical to efficient energy use.