Daikin vs Grant Heat Pumps

Daikin and Grant are both established names in air source heat pumps. Grant's range is built around its Aerona³ system, which uses R32 refrigerant and offers a coefficient of performance (CoP) of up to 4.65. Daikin comes with a CoP of 4.50. Both brands suit homeowners who want to move away from gas or oil heating, and the choice usually comes down to efficiency, warranty and the quality of the installer who fits the system.

Grant's technology is centred on Aerona³, which pairs R32 refrigerant with inverter control. Its smart controllers include weather compensation, which adjusts flow temperature to outdoor conditions, and remote monitoring through a smartphone app. A single Grant system provides heating and hot water, runs efficiently down to -20°C and operates at around 45dB(A). Its monobloc design keeps the footprint compact, and the warranty can reach seven years when installed by an approved installer. Grant's units are MCS certified. Daikin comes with a five-year warranty, a CoP of 4.50 and UK support rated excellent.

Grant suits homeowners who want maximum efficiency and a long warranty, particularly those with well-insulated properties and radiators that can run at lower flow temperatures. Its compact outdoor unit suits gardens where space is limited. Daikin suits households who put UK support first. Most installations fall under permitted development, but check local rules in conservation areas, and get a professional heat loss survey before choosing a system size, whichever brand you pick.

Bottom line: choose Grant if you want the highest efficiency on offer, a CoP of up to 4.65, a warranty of up to seven years and smart weather compensation, provided you use an approved installer. Choose Daikin if you prefer a five-year warranty, a CoP of 4.50 and excellent UK support, and value a brand that prioritises after-sales care.