In its Aquarea L Series propane (R290) residential air-to-water heat pumps, which will be released in Europe by early April 2023, Japanese manufacturer Panasonic has designed a split model in which the R290 is kept outside, along with the main components.
Hot water is created in the outside unit and pumped into the home, where it is used for both space heating and to heat domestic hot water in a water tank, noted Enrique Vilamitjana, Managing Director of Panasonic Heating Ventilation Air-Conditioning, in an interview with Hydrocarbons21.com.
“This is a split type, but what’s moving [from the outside to the inside] is water, not refrigerant,” said Vilamitjana. Panasonic is calling this a “hydrosplit monobloc” design, encompassing a monobloc unit outside with compressor, condenser and evaporator that sends hot water to inside units. This is the first time Panasonic has used this design.
In addition to warming the indoor water tank, the hot water from the outside unit is distributed inside via a space-heating mechanism – whether a radiator, floor heating or a fan coil. In the summer, the heat pump can be used as an air conditioner, pumping chilled water into the home.
In northern climates, Panasonic recommends that installers include an antifreeze valve in the piping, allowing antifreeze to prevent water from freezing in the winter. Glycol could also be used, though it is not as efficient as antifreeze.
The design of Panasonic R290 heat pumps – which come in three capacities, 5, 7 and 9kW (1.4, 2.0 and 2.6TR) – makes them easy to install and maintain, said Vilamitjana. “It’s new, so we wanted to make it easy to install. This premade product facilitates the transition to heat pumps.”
While this is Panasonic’s first R290 heat pump, it is not its first with a natural refrigerant. In Japan, the company has for many years marketed the highly successful Eco Cute hot water heat pump.
Under its REPowerEU plan, the EU is making a major push to decarbonize home heating and switch to electric heat pumps, both to aid the climate and eliminate dependence on Russian natural gas in the wake of the Ukraine war.
At the same time, the EU F-gas Regulation is expected to pursue more aggressive f-gas phase-down targets that will make natural refrigerant heat pumps more attractive. Manufacturers of such heat pumps say they expect to meet the growing demand for their products, addressing concerns that an aggressive f-gas phase down will cause a shortage of refrigerant that will hurt the uptake of heat pumps.
Panasonic’s R290 heat pump will contain 1kg (2.2lbs) of propane, well below the European (EN) standard limit for R290 kept outside (4.94kg/10.9lbs). This remains unchanged in the new global IEC 60335-2-40 V7 standard released in May. However, that standard did increase the amount of R290 allowed in indoor units, with a maximum of 988g (2.2lbs) in rooms starting at about 23m2 (247.6ft2); the EN version is in the process of being updated.
Suited for older radiators
Vilamitjana noted that the R290 heat pump can generate hot water up to 75°C (167°F), which is sufficient to supply space heating for older radiators, in ambient temperatures down to -10°C (14°F). “In Northern Europe, where there will be a lot of retrofitting of buildings, people will be reassured with the 75°C temperature,” he said. “It’s also important that it can perform in low temperatures.”
At the same time the unit supplies the 25°C (77°F) needed for floor heating “so it can cover new uses or old houses with old-style radiators,” he said.
Panasonic will also be introducing the Aquarea K Series heat pumps that will use R32 refrigerant to cover needs in the market not addressed by the R290 units, said Vilamitjana. In particular, the K Series will serve larger capacities, up to 16kW (4.5TR) and cover longer distances from outside to inside (50m/164ft horizontally and 30–40m/98.4–131.2ft vertically).
But the R32 units will only be able to reach 70°C (158°F), not high enough (75°C) for old radiators, which could be served by the R290 units, he noted.
Because of challenges regarding component availability, higher production costs and safety measures, the R290 heat pumps will be 15–20% higher in price than the R32 units. “Some people might pay more for a lower-GWP product” like the R290 model, he noted.
At the same time, the R290 heat pumps offer A+++ efficiencies with a Seasonal COP (SCOP) of up to 5.12 and are “slightly more efficient than the R32 models,” said Vilamitjana.
Both types are up to 8dB(A) less noisy than previous models, which is particularly important in Northern Europe (north of Paris), he said.
Another key feature is connectivity to Wi-Fi and the cloud. “We believe that if we want to make our heat pumps future-proof, they should be connectable,” said Vilamitjana. Connectivity will allow the heat pumps to be easily updated and maintained, the latter being especially important for R290 units. In fact, Panasonic will offer preventive maintenance for the heat pumps. Consumers will also have electronic control of the products, which are smart-grid ready for photovoltaic power operation.
Other notable features of the R290 heat pump are Bluefin anti-corrosion covering for the outside unit and the 598 x 600 mm (23.5 x 23.6 inch) dimensions of the indoor unit, such that it can fit into a standard European kitchen like a household appliance.
“In Northern Europe, where there will be a lot of retrofitting of buildings, people will be reassured with the 75°C temperature.”
Enrique Vilamitjana, Panasonic