Heating & Cooling Game Changer: Why CO2 Heat Pumps Are the Future

Have you ever imagined that the notorious CO2 could be a key player in cooling our planet?

Surprisingly, CO2, often villainized for its role in climate change, is now revolutionizing how we heat our homes and water. This seemingly paradoxical twist is due to its efficiency as a refrigerant in heat pump.

With over double the energy efficiency of traditional systems, CO2 heat pumps are not just an old technology getting newfound attention; they’re a game-changer in our quest for sustainable living.

The Journey of Heat Pumps

heat pump system on side of house

The concept of heat pumps isn’t new; it dates back almost 150 years (ref).

Heat pumps work by using a refrigerant to transfer heat around a space, either warming or cooling it. Initially, harmful substances like chlorofluorocarbons (CFCs) were used, but with their detrimental impact on the ozone layer, the search for alternatives led us to CO2.

The advantages of CO2 are manifold: it’s more efficient in both high and low temperatures, making it a superior choice for domestic water heaters, especially in larger settings like resorts.

Innovating with CO2

Companies like Harvest Thermal are taking heat pump technology to the next level. They’ve built upon Eco2’s SANCO2 heat pump and added two crucial components: a large water tank and a smart management system, the “smart pod.”

This combination isn’t just about heating efficiently; it’s about smart energy management, tapping into cheaper electricity rates and storing energy for later use.

Efficiency Factor

The efficiency of a heat pump is measured by its coefficient of performance (COP).

While your average air source heat pump has a COP of 3, Eco2’s SANCO2 heat pump boasts a COP ranging from 2.6 to 5.5, depending on the temperature. Harvest Thermal’s smart system can push these savings even further, potentially cutting bills by 45% compared to standard gas heaters.

CO2 Heat Pump’s Historical Context

Interestingly, CO2 was one of the first refrigerants used in the early days of refrigeration, alongside ammonia. However, it fell out of favor due to the need for high-pressure systems.

With the phase-out of CFCs and HCFCs in the 1990s (ref), CO2 made a comeback, especially in resource-conscious countries like Japan.

Physics Behind CO2 Heat Pumps

CO2 heat pumps operate at higher temperatures due to their “transcritical” nature, meaning they don’t fully change phase. This, along with CO2’s high specific heat and excellent heat conduction properties, makes it highly efficient in transferring heat.

However, they require more advanced, thus more expensive, components than standard heat pumps.

The Market & Future Prospects

Despite their efficiency, CO2 heat pumps face challenges in widespread adoption due to their higher initial costs and specific installation requirements.

They are, however, gaining traction in large-scale applications like supermarkets and resorts. The future of CO2 heat pumps in residential settings remains to be seen, but their advantages in efficiency and sustainability make them a promising option.

Website | + posts

Davin is a jack-of-all-trades but has professional training and experience in various home and garden subjects. He leans on other experts when needed and edits and fact-checks all articles.