Key factors to check
- Application Space heating, domestic hot water (DHW), or pool heating have different temperature targets and sizing rules.
- Climate & operating range Verify the ambient operating temperature range for your site, especially for winter or low‑ambient pool use.
- Outlet water temperature High‑temperature series are required when your system needs elevated water outlet temperatures.
- Power supply Confirm voltage/phase (e.g., 230V 1‑phase or 400V 3‑phase) to avoid installation surprises.
- Efficiency metrics Use COP/SCOP for heating and EER where cooling is relevant. Seasonal metrics better reflect real energy cost.
Start with the design load, not the old boiler rating
Use the building heat-loss calculation at the local design temperature. An oversized boiler does not reveal the actual peak load, and copying its nominal power can lead to short cycling, higher cost and less stable comfort.
Compare performance at the same test point
Compare heating capacity and COP only when outdoor air and leaving-water conditions match. A7/W35 and A7/W55 describe different duties; the warmer water condition normally requires more compressor work.
Check hydraulics, emitters and minimum output
Confirm design flow, pressure drop, water volume and emitter capacity at the intended water temperature. Minimum modulation also matters because it affects cycling during mild weather and low-load operation.
Review sound and installation constraints
Check sound power, clearances, airflow, condensate and defrost drainage, service access and the electrical connection. Placement near reflective walls or neighbouring windows needs specific acoustic review.
Confirm the final selection against the full project
The shortlist should be checked against the lowest outdoor temperature, required leaving-water temperature, domestic hot water duty, backup strategy and applicable local design requirements before ordering.
AQVOCLIMA tip
Use our Heat Pump Selector to shortlist models by application, capacity, efficiency, and power supply—then confirm final sizing with project conditions.