Karnot iSTOR P58 Thermal Battery
Thermal storage solution for decarbonising heating and hot water
The Karnot iSTOR P58 provides highly efficient, low-carbon heating for commercial buildings and industrial processes. Up to three times smaller than the equivalent hot water based thermal store, the iSTOR P58 is a space-saving alternative to water tanks and buffer vessels used in buildings for buffering heat.
Key Features & Advantages
Engineered for maximum energy density and operational flexibility — the iSTOR P58 delivers powerful thermal storage in a compact, efficient package.
High Energy Density
Delivers a nominal storage capacity of 80 kWh in a compact form, making it an ideal replacement for bulky hot water tanks.
Powerful & Flexible Output
Features two independent hydronic circuits (High Power and Low Power) that can be configured to suit any application and load requirement.
Rapid Charge & Discharge
High flow rates allow the battery to be charged quickly from any heat source and to deliver high-temperature hot water on demand.
Minimal Standby Loss
Engineered for maximum retention, with a low standby energy loss of just 3.0 kWh per 24 hours.
Technical Specifications
Comprehensive specifications for system design and installation planning.
Performance & Capacity
| Nominal Storage Capacity | 80 kWh273 kBTU |
| Standby Stored Energy Loss Rate | 3.0 kWh / 24h10.2 kBTU / 24h |
| Design Discharge Outlet Temperature | 54°C129.2°F |
| Charging Source Temperature | 65°C to 80°C149°F to 176°F |
Operational & Physical
| Max Flow Rate (High Power Circuit) | 50 L/min13.2 gal/min |
| Max Flow Rate (Low Power Circuit) | 40 L/min10.6 gal/min |
| Maximum Working Pressure | 1.6 MPa (16 bar) |
| Dimensions (W × D × H) | 1200 × 1000 × 1470 mm47″ × 39″ × 58″ |
| Weight | 1,402 kg3,091 lbs |
Additional Advantages
Beyond core performance, the iSTOR P58 delivers system-wide benefits that transform how you manage thermal energy.
System Benefits
- Charges from multiple energy and heat sources
- Decouples heat sources from heating demands
- Offers demand side management and shifts heating loads to cheaper off-peak tariffs
- Reduces pre-heat time required in buildings
- Modular and scalable — thermal batteries can be connected in series or in parallel to increase heat storage capacity
- Combines with HVAC&R equipment, and integrates solar thermal and solar PV systems with existing heating plant
Lower Costs
A Karnot iSTOR P58 thermal battery is clean and fast to install. There's no need to increase the size of expansion vessels nor the volume of water treatment chemicals. Running costs are also low because mandatory annual maintenance and inspections are not required.
Note: As an innovative company committed to continuous improvement, our products are subject to change without prior notice. Always refer to the latest version of this document.
Ready to Optimise Your Thermal Storage?
Contact our technical team for system design assistance and detailed project specifications.
Contact Sales