Grant’s Aerona R290: A next-gen heat pump designed for the Irish climate

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Grant’s latest innovation, the Aerona R290 air-to-water heat pump, delivers on that front—with design and performance characteristics that align with the expectations of the passive house and low-energy building community.

Engineered and tested specifically for the damp, variable conditions typical of Ireland and the UK, the Aerona R290 uses natural R290 refrigerant with an ultra-low global warming potential (GWP) of just 3—positioning it among the most climate-conscious heat pump options currently on the market.

The range includes outputs from 4kW to 16kW across five models, giving designers and specifiers flexibility to cover individual low-energy homes, deep retrofits, or large-scale housing schemes. According to Grant, the Aerona R290 is the only range of its kind currently available in Ireland to offer this level of diversity in output within a single product line.

The range offers not just variety but performance specific to Ireland’s climate, the company said. One of the well-documented challenges for air source heat pumps in high-moisture environments is frost formation on the outdoor coil, particularly during foggy or frosty periods. Many units respond with frequent defrost cycles—leading to inefficiencies, greater wear-and-tear, and reduced comfort for occupants. The Aerona R290 addresses this with a carefully engineered design, including enhanced drainage, protective coatings, and a control logic that minimises energy lost to defrost cycles.

Speaking about the design of the Aerona R290 heat pump, Grant R&D manager, Peter Darcy said, “When designing the new heat pump, we listened carefully to our customers. Not only did this influence the aesthetic look of the unit but also the acoustic qualities and most importantly, the performance. A reliable, high efficiency and sustainable heating system was of utmost importance, and we have ensured the Aerona R290 delivers on all of these elements.”

Each unit in the range achieves an A+++ energy rating at 35C flow temperature and has been tested and rated for -5C outdoor air temperature and 55C water flow temperature—conditions more in line with real-world operation than many standard test scenarios. The result is a system that continues to deliver consistent heat output and low operational costs, even in the most moisture-laden Irish winters. From an embodied carbon perspective, the use of R290 is a forward-thinking choice. With upcoming changes to refrigerant regulations in the EU and UK, systems using natural refrigerants like propane are set to become a key way of reducing the impact of heat pump manufacturing.

Grant’s €2.4 million investment in the Aerona R290 development underscores the company’s commitment to the long-term decarbonisation of home heating. For those involved in passive house, NZEB and other low-energy projects, the Aerona R290 offers a reliable, efficient, and climate-appropriate solution—designed and built in Ireland, for Irish conditions.

Visit www.grant.ie more information on Grant’s range of innovative heating solutions. Follow Grant on Facebook @GrantIRL, X and Instagram @grant_irl and LinkedIn @GrantEngineeringULC. You can also subscribe to Grant on YouTube @GrantEngineeringIE