scope:

Scope and purpose

In building technology a wide variety of systems are used for heating drinking water. A suitable system can only be selected if the alternatives have been assessed in terms of energy efficiency and economy. It is necessary to calculate the effective energy requirement for the so-called "reference use" at the tapping points of a drinking water heating system (see Section 3). Individual requirements which deviate from the reference use must be recorded separately, see also the reference use terminology. In addition, there is the expenditure of energy involved in the transfer of utility, the distribution, provision and production of the heated drinking water, see Part 22 ff.

The effective energy requirements given for residential buildings should be regarded as guidance, particularly where the energy requirement values cannot be determined precisely.

Every figure relating to energy requirement is associated with a process (e.g. total body cleaning) and with an appliance (e.g. shower) and therefore an appropriate distinction is also made in Table 1. Although belonging to the user establishment, the drawoff tap (manually controlled as a single or doublelever mixer or thermostatically controlled) does not influence the effective energy requirement, but does influence the expenditure of energy during the transfer of utility. Therefore the type of draw-off tap is not taken into consideration as a further possible criterion.