A51 -- Service Water Heating (SI)

Water heating energy use is second only to space conditioning in most residential buildings, and is also significant in many commercial and industrial settings. In some climates and applications, water heating is the largest energy use in a building. Moreover, quick availability of adequate amounts of hot water is an important factor in user satisfaction. Both water and energy waste can be significant in poorly designed service water-heating systems: from over- or undersizing pipes and equipment, from poor building layout, and from poor system design and operating strategies. Good service water-heating system design and operating practices will reduce operating costs and can often reduce first costs. The information in this chapter is thus critical for the sustainable design and operation of many buildings. System Elements Water-Heating Terminology System Planning Design Considerations End-Use Fixtures Distribution Water-Heating Equipment Building Applications Hot-Water Load and Equipment Sizing Water-Heating Energy Use Health and Safety Water Quality, Scale, and Corrosion Special Concerns