The choice of device in central heating systems varies depending on the building’s plumbing structure and requirements. Here are the main differences between the two devices:
1. Technical Specifications and Measurement Method
| Feature | Heat Cost Allocator | Calorimeter (Heat Meter) |
| Measurement Principle | Operates with dry sensors that measure the radiator surface temperature and ambient temperature. | Measures by multiplying the temperature difference of the water entering and leaving the apartment by the flow rate. |
| Accuracy | Provides high accuracy with dry sensors. Protected against manipulation (such as cooling or covering). | Measures with sensors inside the water. Calcification or plumbing faults can affect its accuracy. |
| Device Structure | Contains no moving parts; does not come into contact with water. | Available in Mechanical (impeller) or Ultrasonic (mirror) types; water flows through it. |
2. Calibration and Maintenance
- Heat Cost Allocator: Does not require calibration. It operates with batteries that have an 8-10 year lifespan and can be used without replacement until the battery is depleted.
- Calorimeter: By law, it is mandatory to have it calibrated and its accuracy checked every 5 years.
3. Failure Risks
- Heat Cost Allocator: Since it has no moving parts, the failure rate is very low. It can only be damaged by physical impact or contact with water (from outside the radiator).
- Calorimeter: Mechanical models can become clogged or wear out due to dirt in the plumbing. In ultrasonic models, calcification and corrosion can damage the measuring mirrors, reducing accuracy.
4. Installation and Application Areas
- Heat Cost Allocator:
- Installation: There is no need to dismantle the plumbing or drain the water. It is quickly mounted to the radiator surface using special installation tools.
- Application: Generally preferred in buildings with vertical pipe (riser) systems. It can be applied to any apartment with radiators.
- Calorimeter:
- Installation: Easy in new buildings, but can be cumbersome in old buildings due to space constraints or plumbing incompatibility.
- Application: Used only in systems where heat enters the apartment from a single point (manifold systems). Its use is mandatory in buildings with underfloor heating.
5. Billing and Control Advantages
- Heat Cost Allocator: Since it is installed separately on each radiator, room-based consumption tracking can be performed. In the event of high bills, it is easy to identify which room has heat loss or which valve is faulty.
- Calorimeter: Measures the total energy (in kW) entering the apartment. It generates a general bill on an apartment basis but does not offer radiator-based (room-by-room) tracking.