London, United Kingdom
Cosy 6 is an innovative 6kW R290 air source heat pump system, first launched to market in June 2024 by Octopus Energy.
Cosy-6 was in-house designed, manufacture, powered, remotely managed, and supported. This gives us full control and agility to optimise green performance and customer experience throughout the product lifecycle.
Octopus Energy Cosy-6, won a 2025 Good Design Award from The Chicago Athenaeum: Museum of Architecture and Design and European Centre for Architecture, Art, Design, and Urban Studies.
Cosy-6 heat pumps. were designed to be more compact and easier to install than traditional metal heat pump units – improving on cost, space, and emissions savings.
The Cosy-6 heat pump showcases a highly innovative design with a visually appealing, fully recyclable modular plastic casing that enhances longevity while generating less waste compared to traditional boxy, sheet metal units.
It is designed to be easily carried by just two people, which helps reduce the size of the installation team.
Installation is further simplified with only four main connections required, minimising complexity. Additionally, the heat pump features remote data monitoring capabilities, enabling optimisation of performance and pre-emptive resolution of potential issues.
At the heart of the unit is the refrigerant circuit – a fully sealed, closed-loop system that uses a compressor to move the R290 working fluid through the refrigerant cycle.
The refrigerant circuit pulls heat from the air via a corrosion-resistant evaporator and moves it into the home through a microplate heat exchanger.
These systems are controlled by an inverter drive that can vary the compressor speed for maximum efficiency, and two proprietary circuit boards.
All these digital components are mounted on a unique, patented “cold plate” that uses a network of pipes embedded in a machine aluminium base to scavenge excess heat from the electronic components, ensuring nothing is wasted.
The Cosy-6 heat pump features an innovative, fully recyclable modular plastic casing that is visually appealing and more sustainable compared to traditional sheet metal units.
It is lightweight enough to be carried by two people, reducing the installation team size, and requires only four main connections, which simplifies installation.
Additionally, it includes remote data monitoring for performance optimisation and early issue detection.
This compact, user-friendly design enhances both ease of installation and ongoing system management.
The MCS-certified heat pumps are 4x more efficient, and emit 84% less emissions than top-performing gas boilers.
Emissions fall by 100% when customers use 100% renewable energy like our smart Cosy triple-dip tariff to power them.
Our Cosy 6 heat pump also uses R290 as a refrigerant, which is both natural and offers a global warming potential 200-300 times lower than previous R32 designs.
The Cosy-6 heat pump delivers strong environmental, business, and customer benefits.
Each household saves about 2 metric tonnes of CO2 yearly, and with up to 30,000 units made annually, total savings reach around 60,000 metric tonnes.
Its warranty and servicing cost 60% less than typical boiler cover. Customers praise its warmth, the peace of mind from being off the gas grid, the less intrusive outdoor pump, and its smooth, efficient performance.
Project: Cosy-6
Designers: Jason Cassells, Colin McKinstry, and Gerard McMahon, Octopus Energy
Manufacturer: Octopus Energy
