Decription:

Hot water plays a major part in modern life. We each use between 40 and 60 litres of hot water per day to wash ourselves, our utensils and our clothes and the production of hot water represents a significant part of the nation's energy consumption. About 14% of total energy and 35% of all electricity is used domestically and about 40% of domestic energy consumption is used for water heating.

Since the 1960s there have been many developments in the technology of domestic hot water. Whereas earlier systems were almost all low pressure, there is now a wide choice of operating pressures, heating methods and delivery systems. As a consequence, the number of decisions that need to be made to achieve a safe, effective and energy efficient hot water system that suits the needs of a particular household has increased to the point that it is no longer simply a matter of saying "there shall be a hot water supply".

Too many houses are still being built with inadequate hot water systems and the deficiencies incorporated during construction usually remain with the house for its life. There are a huge number of households in which the hot water supply is (sometimes woefully) lacking because of inadequate quantities of water, inadequate and variable flow and/or dangerously high temperatures. In many cases the system uses a great deal more energy than is necessary.

For many of these installations relatively simple changes to the existing system can greatly enhance the safety, effectiveness and energy efficiency (and hence the operating costs) of the hot water supply.

Topics covered in this book include:

* an introduction to water heating systems;
* the properties of water;
* hot water use in domestic dwellings;
* hot water storage, pressure control and temperature management;
* safety aspects of water heating systems and the NZ Building Code;
* distribution and delivery of hot water; and
* alternative sources of energy for water heating.

This book endeavours to bring together in one place the information and experience needed to provide good initial design and effective upgrades of existing systems with particular reference to New Zealand domestic practice.