ISO 19967-1:2019 pdf download – Heat pump water heaters — Testing and rating for performance — Part 1: Heat pump water heater for hot water supply. 5 Installation requirements 5.1 Test apparatus and uncertainties of measurement The test apparatus shall be designed in such a way that all requirements for adjustment of set values, stability criteria and uncertainties of measurement according to this document can be fulfilled. Water systems or other heat transfer liquid systems shall be sufficiently free of entrained gas as to ensure that the measured results are not significantly influenced. The inlet and outlet temperatures of the...