Division 5 Water heating energy efficiency of combination heaters

The water heating energy efficiency η_wh of a combination heater shall be calculated as the ratio between the reference energy Q_ref and the energy required for its generation under the following conditions:

1. (a)

   measurements shall be carried out using the load profiles set out in Table 15;

2. (b)

   measurements shall be carried out using a 24-hour measurement cycle as follows:

   • 00:00 to 06:59: no water draw-off;

   • from 07:00: water draw-offs according to the declared load profile;

   • from end of last water draw-off until 24:00: no water draw-off;

3. (c)

   the declared load profile shall be the maximum load profile or the load profile one below the maximum load profile;

4. (d)

   for heat pump combination heaters, the following additional conditions apply:

   • heat pump combination heaters shall be tested under the conditions set out in Table 9;

   • heat pump combination heaters which use ventilation exhaust air as the heat source shall be tested under the conditions set out in Table 11;

5. (e)

   the annual electricity consumption AEC in kWh in terms of final energy shall be calculated as daily electricity consumption Q_elec in kWh in terms of final energy multiplied by 220;

6. (f)

   the annual fuel consumption AFC in GJ in terms of GCV shall be calculated as daily fuel consumption Q_fuel multiplied by 220.