What is ISO 21978 about?
ISO 21978 specifies test conditions for determining the seasonal performance characteristics of air source heat pump water heaters for space heating with electrically driven compressors with or without supplementary heater.
ISO 21978 specifies the technicalities such as terms, definitions, symbols, installation requirements, setting and part load test conditions, space heating test, calculation methods for seasonal co-efficient of performance (SCOP), test results and test reports for testing and rating of heat pump water heater.
ISO 21978 defines:
- Three design conditions, each of them being characterized by a design temperature which represents the lowest temperature that can occur in that design condition
- Three water temperature distribution regimes, namely “temperature application” in the text
Note 1: ISO 21978 provides a full description of three heating seasons that can be used with the associated design conditions
Note 2: ISO 21978 determine the seasonal coefficient of performance for one or more of the defined design conditions and for one or more of the defined temperature applications.
Note 3: In the case of heat pump water heaters for space heating consisting of several parts with refrigerant or water connections, ISO 21978 applies only to those designed and supplied as a complete package.
Who is ISO 21978 for?
ISO 21978 on heat pump water heater is applicable on:
- Manufacturing industries of water heater
- Suppliers and distributors of water heaters
- Companies dealing with water heater and heat pumps
Why should you use ISO 21978?
Heat pump water heaters uses the electricity to move the heat from one place to another, instead of generating the heat directly.
ISO 21978 provides part load conditions and calculation methods for calculating the Seasonal co-efficient of Performance (SCOPon and SCOPnet) of units when they are used to fulfil the heating demands.
ISO 21978 provides you the operating conditions which can be better assessed by comparing equipment at representative reduced capacities and determining the Seasonal Coefficient of Performance.
ISO 21978 guides you in heat pump water heater standard for installing and connecting of the heat pump, which shall be installed and connected for the test as recommended by the manufacturer in the installation and operation manual.
ISO 21978 serves the purpose of rating the performance of the heat pump water heaters for space heating with no operation of any supplementary heater.
