This week we have been to the Netherlands and tested the HeatSnagger at KIWA according to the standard NEN 5128 A1:2009 which prescribes performance testing for DWHR systems for shower. The test uses a 40°C input drain water temperature, 10°C cold water temperature and two flow settings, respectively 9.2l/min and 12.5l/min. The flow is balanced meaning that the cold water flow equals the drain water flow (equivalent to an installation scheme feeding both shower valve and water heater). In the test certificate, the efficiency of the unit is reported as well as the pressure loss across the cold water connections at the given flows. The key numbers from the KIWA test of the dwhr unit HeatSnagger are:
9.2l/min : 19.7% efficiency (Power transfer of 3.9kW, pressure drop 240 mbar)
12.5l/min : 17.7% efficiency (Power transfer of 4.7kW, pressure drop 360 mbar)
We also did a pressure test of the pipe assembly to 16 bar and the unit survived this without problems.