prEN 50XXX

Devices for heat recovery from shower wastewater (DWHRD) prEN 50XXX

Scope

Scope
This document is applicable to pre-fabricated devices for heat recovery from shower wastewater (DWHRD, drain water heat recovery devices), consisting of a heat exchanger having a vented primary side and a pressurised secondary side, which are capable of achieving a volume flow rate on the secondary side of at least 12,5 l/min.
It contains a procedure for calculating the overall efficiency from the efficiency of the DWHRD and the efficiency of the electric water heater. In addition, parameters are determined for the calculation of building codes within the framework of the EPBD.
DWHRDs are not required to be installed directly on the shower, but can instead be deployed at any point in the shower wastewater operating conditions:
1) Primary side:
— maximum operating pressure up to 250 kPa;
— maximum continuous temperature up to 40 °C.
2) Secondary side:
— maximum operating pressure up to 1 000 kPa (in accordance with DIN EN 806 (all parts));
— maximum continuous temperature up to 40 °C;
— maximum pressure loss between infeed and outlet on the secondary side of 60 kPa at the nominal volume
flow rate.
This document is not applicable to devices for heat recovery from wastewater with a storage reservoir.