Total Thermal Capacity for IHEAB implementations clarified in ESS Rule change
The latest change to the ESS Rule introduced an updated definition for Total Thermal Capacity for heat pump water heater implementations under Activity definition F16 (IHEAB). HPCap is based on Total Thermal Capacity which includes thermal capacity for the heat pump and the booster(s). To calculate Total Thermal Capacity, sum:
- total heat pump thermal capacity (available on the accepted products list ); and
- the thermal capacity of electric booster(s), if any (use product manual, test results or certifications).
Update your business processes to make sure you calculate HPCap by accounting for the thermal capacity of the heat pump and the booster if there is one.
Change to accepted product list for heat pump water heater systems (IHEAB)
Total Thermal Capacity values for heat pump hot water heaters accepted prior to 12 September 2025 are being reviewed. This is to make sure they meet the definition in the ESS Rule. Until the review has been completed, Total Thermal Capacity values will not be available in the accepted product list. Products listed after 12 September 2025 will not be affected by this review.
If you have any questions about changes to the product list, please email essproducts@ipart.nsw.gov.au.