A new study conducted under real-world conditions validates the heat pump solution more than ever.

This measurement campaign validates the excellent performance of air-to-water heat pumps in one of the coldest climate zones in France (H1), provided that the sizing-installation-monitoring process is properly managed. With this new study, DOMOSOLARIS and PANASONIC reaffirm their shared commitment: to make the air-to-water heat pump the central lever for decarbonizing heating in single-family homes, including in the most demanding climate zones.

A groundbreaking campaign testing 113 heat pumps under real-world conditions

Between winter 2024 and spring 2025, DOMOSOLARIS recorded the performance of 113 Aquarea R32 monobloc air-to-water heat pumps installed at its customers' premises. Each unit underwent a complete survey during an annual maintenance visit (energy consumed, energy delivered, operating temperatures), allowing the calculation of three key seasonal indicators: the SCOP Heating (average seasonal efficiency of the heating circuit), the SCOP DHW (average seasonal efficiency for domestic hot water production) and finally the Overall SCOP (efficiency of the entire heating + DHW system)*.

On each of the three indicators, the DOMOSOLARIS fleet achieves excellent performance, even though all installations are located in the most unfavorable climatic zone for an air-to-water heat pump, namely zone H1, which includes Isère, Savoie, Haute-Savoie, and Drôme. The average recorded SCOP for heating is 4.00, the SCOP for domestic hot water is 3.67, and the overall SCOP is 3.93.

SCOP Heating: The impact of the emitter on heat pump performance confirmed

The study of the performance distribution of DOMOSOLARIS heat pumps also shows the influence of the emitter (radiator, underfloor heating) on ​​the heat pump's performance. For example, around twenty residences show SCOPs between 3.3 and 3.5, corresponding to installations where the heat pump is connected to a medium-temperature radiator (typical water temperature of 45-55°C). Panasonic's manufacturer specification for this type of configuration in a temperate climate predicts a SCOP of around 3,4; the DOMOSOLARIS system is perfectly aligned with this, especially considering its cold climate. On the other hand, about ten units show SCOPs around 4.8 or 5.0. These correspond to heat pumps connected to underfloor heating (typical water temperature of 30-35°C). The manufacturer's specification for this type of installation is around 4,9; this is also achieved under real-world conditions and in zone H1.

Overall, the expected performance meets expectations for the various heat emitters installed in the homes studied. Furthermore, achieving this performance in climate zone H1 clearly demonstrates that a properly sized, installed, and maintained heat pump maintains excellent performance even in cold climates.

SCOP ECS: efficient hot water production if the settings are correctly respected.

Domestic hot water production is sometimes the weak point of air-to-water heat pumps. The DOMOSOLARIS fleet achieves a SCOP of 3.67.

Three key findings emerge from the study of the distribution of domestic hot water (DHW) SCOP across the DOMOSOLARIS portfolio. A small fraction of installations exhibit a DHW SCOP below 3.0. This can be explained, firstly, by the presence of continuous losses, forcing the heat pump to resume production regularly. The SCOP can be significantly impacted, especially if hot water consumption is low. Secondly, it can be due to a high tank temperature setpoint (55 to 60°C, sometimes higher): above 55°C, the heat pump operates with reduced efficiency. Performance can also be affected by the activation of the anti-legionella mode, which raises the tank temperature above 60°C at least once a week, often using auxiliary heating elements.

Better performance is observed with a setpoint temperature around 52°C. Finally, such results can also be explained when the tank is oversized and consumption is very low. Static losses become proportionally too significant for tanks used infrequently.

In other words, the SCOP DHW (domestic hot water) is not a hardware problem, it's a settings problem. On the same Panasonic heat pump range, we observe a SCOP DHW that varies from 1,9 to 4,8 depending on the tank configuration and user settings.

Excellent performance of air-to-water heat pumps even in cold climates

One of the key takeaways from this campaign dispels a persistent misconception about heat pumps: that they only function in mild climates. On the contrary, even in demanding climatic conditions, heat pump performance remains consistent, with some units reaching or even exceeding manufacturer specifications. This study therefore confirms that the performance of heat pump heating depends on a combination of quality equipment and sound installer practices, including proper sizing, installation, and ongoing maintenance.

For its part, DOMOSOLARIS focuses heavily on the three key factors that determine a heat pump's performance. Each project involves calculating heat loss room by room using an in-house tool developed by DOMOSOLARIS, in strict compliance with the QualiPAC standard. The heat pump's power output is then selected based on these actual heat losses, thus avoiding oversized or undersized units. DOMOSOLARIS implements best installation practices that guarantee optimal performance. All installed heat pumps are connected to Panasonic's Aquarea Service Cloud platform. This remote monitoring allows the after-sales service to perform predictive maintenance: early detection of performance deviations, alerts for cycling anomalies, optimization of the heating curve, and adjustment of domestic hot water (DHW) setpoints without requiring on-site visits. This is a crucial tool for quickly correcting any installations that deviate from expected performance and maintaining a high SCOP (Seasonal Coefficient of Performance) over time.

For Thierry Ronat, Country Manager Panasonic heating & cooling solutions: “We are currently experiencing a major energy crisis that is forcing us to revise the timeline and accelerate our energy transition and the decarbonization of housing more than ever. This study conducted by DOMOSOLARIS proves, unequivocally, that heat pump technology is the answer for an efficient, cost-effective, and carbon-free heating system. As for Panasonic, we have the widest product range on the market, allowing us to meet all needs: from single-family homes, old or new, to apartments, and even condominium buildings, so let's get started!”

For Arnaud Gabel, Head of Business Development at DOMOSOLARIS: "With this new study, we demonstrate that performance is not a matter of climate or luck: it is built project after project, through rigorous heat loss calculations, installation in accordance with best practices, and remote monitoring that allows us to act before a malfunction degrades the customer's comfort or bill."

Scope of the DOMOSOLARIS study

113 Panasonic Aquarea R32 monobloc air-to-water heat pumps, primarily HP/T-CAP size 9 models (full range observed: HP size 5 to T-CAP size 16). • Installations in renovation projects, replacing gas or oil boilers. • Older houses (poorly insulated stone buildings, and up to RT 2010 standards for the most recent), average heated area ~130 m². • Average domestic hot water tank: 200 liters. Most installations provide dual service (heating + domestic hot water). • Climate zone H1C, basic outdoor temperatures from -7°C to -14°C (average ~-11°C).

Seasonal performance was calculated from operating data collected during annual maintenance visits (electrical consumption, heat produced and operating temperatures), with an identical calculation method applied to all the installations studied.

*DOMOSOLARIS, internal analysis campaign of 113 Panasonic Aquarea R32 heat pumps - 2024 and 2025 seasons.

**Decree of 15 December 2025 amending provisions relating to standardized operation sheets BAR-TH-171 "Air/water type heat pump" and BAR-TH-172 "Water/water or glycol/water type heat pump" within the framework of the energy savings certificates scheme

Illustrative image of the article via Depositphotos.com.