In the race to decarbonize buildings and modernize HVAC systems, not all heat pumps are created equal. While many manufacturers are switching to low-GWP refrigerants, Dalrada Technology Group is leading with a bold, forward-thinking solution: the DCT-1, a CO₂ heat pump that uses a transcritical cycle for unmatched efficiency and dual functionality.
But what does supercritical CO₂ mean — and why does it matter?
Let’s break it down.
What Is Supercritical CO₂?
Carbon dioxide (CO₂ or R-744) becomes supercritical when it’s heated and pressurized beyond its critical point — specifically:
- Critical Temperature: 88°F (31°C)
- Critical Pressure: 1,071 psi (7.38 MPa)
At this point, CO₂ no longer behaves like a gas or a liquid, but takes on supercritical properties: a dense fluid with gas-like flow and liquid-like heat absorption. This unique state allows it to transfer heat with extraordinary efficiency, especially at high temperatures.
Why Is Supercritical Operation Important in a Heat Pump?
Most traditional heat pumps rely on phase change in the condenser — refrigerants switching from gas to liquid. This works well at moderate temperatures but struggles with extreme demands — especially when high hot water temperatures are needed.
Transcritical CO₂ systems, by contrast, operate in and out of the supercritical state, using continuous, highly efficient thermal transfer. That translates to:
- Higher achievable water temperatures (up to 185°F / 85°C)
- More efficient heat exchange across wider temperature ranges
- Consistent performance even in colder ambient climates
How the DCT-1 Uses Supercritical CO₂ — and What Makes It Different
Dual Output: Hot & Cold Water — Simultaneously
While most systems provide heating or cooling, the DCT ONE delivers both — simultaneously — with precise control and high output. It can provide:
- Hot water up to 185°F (85°C)
- Chilled water down to 32°F (0°C)
All from a single, compact unit. That’s ideal for commercial buildings, hospitals, gyms, hotels, and data centers — environments where heating and cooling loads exist side by side.
Transcritical Performance Through Advanced Phase Behavior
Unlike traditional systems that rely on phase change in the condenser (switching from gas to liquid), the DCT-1 uses a transcritical CO₂ cycle with three distinct phase transitions:
- Gas → Supercritical fluid (during compression)
- Supercritical → Liquid (post gas cooler, via expansion)
- Liquid → Gas (in the evaporator)
Instead of condensing in the gas cooler (as conventional systems do in a condenser), CO₂ remains in a supercritical state while rejecting heat — one of the defining features of a transcritical system.
This approach enables very high discharge temperatures from the compressor — a key to the system’s exceptional heat transfer efficiency. The greater the temperature difference between CO₂ and the water, the more effectively the system transfers energy.
Sustainability Without Compromise
Unlike synthetic refrigerants like R-410A or R-134a, CO₂ (R-744):
- Has a Global Warming Potential (GWP) of just 1
- Is non-flammable and non-toxic
- Is naturally occurring, abundant, and affordable
By combining CO₂ with transcritical operation, the DCT-1 delivers world-class efficiency with near-zero environmental impact — ideal for future-forward infrastructure and compliance with global refrigerant phase-downs.
High COP – Lower Operating Costs
Thanks to the large operating range of the transcritical CO₂ cycle, the DCT-1 boasts a Coefficient of Performance (COP) of up to 7.0 — meaning it delivers 7 units of heating or cooling energy for every 1 unit of electricity consumed.
That’s far beyond conventional heat pump efficiency and translates to:
- Lower energy bills
- Reduced grid demand
- Shorter ROI periods for facility upgrades
Why This Matters for the Future of Commercial Buildings
As governments phase down high-GWP refrigerants and large facilities look for ways to electrify, heat pump innovation must go beyond just regulatory compliance. It must deliver:
- Higher performance
- Lower emissions
- Smarter integration
- Operational versatility
The DCT-1 checks all those boxes.
It’s not just a heat pump — it’s a technological leap forward.
In Summary: Supercritical CO₂ = Smarter, Greener HVAC
| Feature | Conventional Heat Pumps | DCT-1 (Transcritical CO₂) |
| Refrigerant | Synthetic (HFCs) | Natural CO₂ (R-744) |
| Hot Water Output | ~130–140°F | Up to 185°F |
| Cooling Output | Typically separate system | Simultaneous chilled water |
| Efficiency (COP) | ~2.5–4.0 | Up to 7.0 |
| Sustainability | Moderate GWP | GWP = 1 |
| Operating Principle | Phase change | Transcritical CO₂ cycle |
Next Steps
Dalrada is advancing transcritical CO₂ technology for commercial and industrial applications. Explore Dalrada’s commercial heat-pump solutions or learn more about the DCT-1 CO₂ heat pump for projects requiring high-temperature hot water and simultaneous heating and cooling.
Contact our team to explore how transcritical CO₂ can drive your building’s performance into the future.
