Heat pumps are widely recognised as the key technology to decarbonise building heat demand in Ireland. To receive grants for heat pumps, homeowners in Ireland are required to have a heat demand per unit of floor area, known as a ‘heat loss indicator’ (HLI), below a certain level. The HLI requirement was designed to protect households from high bills if they switched to a heat pump.
There is a concern that the HLI is limiting heat pump deployment, thereby hindering Ireland’s goal of net zero in 2050. This review of the HLI policy and associated rules was undertaken alongside a discussion of heat pumping technologies and their operation, optimal performance and innovation. While there is still a major role for building fabric energy efficiency upgrades, innovation in heat pumping technologies means they may be able to more easily replace combustion-based technologies than has been previously assumed due to better performance and higher output temperatures.
To achieve more rapid and potentially smoother deployment of heat pumps, current HLI grant requirements should be reevaluated. Initially, the HLI requirements could be loosened, subject to relevant consumer advice and protections. In the longer term, a focus on flow temperatures and in-situ performance may be more appropriate. Building fabric efficiency requirements could be maintained but simplified. Finally, trials and programmes to evaluate heat pump performance in Irish buildings should be expanded and expedited in order to provide accurate and local data on this strategically important technology.