Hot Water

Much of the water used in a bathroom is heated. Wasting water would also be wasting the energy used to heat the water. Conserving and reducing the energy used to heat water are part of a sustainable home.

Insulating hot water pipes reduces standby heat loss. Putting a secondary water heater in or near the bathroom minimizes the water that is wasted waiting for the hot water to reach the bath­room and well as the energy lost when the hot water cools in the pipes after hot water is no longer drawn by a bathroom fixture. Installing a tankless or on-demand water heater in the home adds the additional savings in energy that is no longer used to maintain a storage tank of hot water.

In this book, installing, locating, and selecting water heaters are discussed in chapter 2, "In­frastructure Considerations," and chapter 7, "Mechanical Planning." It is also important to select a water heater that is energy efficient and sized to household needs. A too-large water heater will use extra energy and provide more hot water than is required. There are several technologies and water heater designs that offer particular advantages in energy efficiency. These technologies include high-efficiency gas, tankless (on-demand), heat pump, condensing, and solar.

Подпись: Energy Star® Energy Star is an international symbol of premium energy efficiency (see Figure 3.6). In the united States, Energy Star is a program of the Environmental Protection Agency and the department of Energy that promotes the

If a design project will include the need to specify a new water heater, or will include water features that increase the use of hot water, you should encourage your client to consider an energy-efficient water heater. For example, an Energy Star-rated water heater would be a good choice. In addition, some local codes may specify the type or efficiency of a new water heater for remodeling, replace­ment, or new construction.

protection of the environment through energy-efficient products and practices.

Energy Star was established to:

• Reduce greenhouse gas emissions and other pollutants caused by inefficient use of energy.

• Make it easy to identify and purchase energy-efficient products without sacrificing performance, features, and comfort.

Energy Star product specifications are based on the following key guiding


• Product categories contribute significant energy savings.

• Qualified products deliver the features and performance demanded by con­sumers as well as increased energy efficiency.

• If the energy-efficient product costs more than a less-efficient product, the purchaser recovers their increased cost through utility bill savings within a reasonable period of time.

• Energy efficiency is achieved through broadly available, nonproprietary technologies.

• Product energy consumption and performance can be measured and verified.

• Labeling effectively differentiates energy-efficient products.


Hot Water

FIGURE 3.6 The Energy Star logo is found on Qualified products.


A wide variety of products are certified as energy efficient by Energy Star. Product categories of particular interest to bathroom designers include clothes washers, dehumidifiers, light bulbs and fixtures, ventilating fans, and water heaters.

Further information and lists of qualifying Energy Star products can be found at www. energystar. gov.