The short version
- Think of EN 14825 as a structured way to compare performance under defined conditions.
- Rated output is not the whole story—part load and seasonal behavior matter.
- Always check the water temperature reference (e.g., 35°C vs 55°C).
35°C vs 55°C
35°C is common for underfloor systems; 55°C is closer to radiator-type applications. Efficiency drops as the required outlet temperature rises.
Part load and climate bins
Seasonal testing evaluates operation across a range of outdoor-temperature intervals and load conditions. This is more representative than treating one full-load point as the expected result for an entire heating season.
SCOP is not the same as COP
COP is the ratio measured at a stated operating point. SCOP combines performance across the defined heating season and includes the framework’s part-load and auxiliary-energy assumptions. Always compare values for the same climate and water-temperature application.
What to compare
Compare models at the same water temperature category and similar ambient conditions. Mixing 35°C values with 55°C values is like comparing espresso machines to kettles.
Capacity at the design condition still matters
A strong seasonal figure does not replace a capacity check at the project’s design temperature. Verify the published heating output, defrost behaviour and any planned backup heat at the conditions the system must actually serve.
European regulatory context
European ecodesign and energy-labelling rules reference seasonal space-heating performance for heat-pump packages. Consult Commission Regulation (EU) No 813/2013 and Commission Delegated Regulation (EU) No 811/2013 for the official regulatory text.