Start with the building. Then size the system.
Hydronic design is about matching the heat source, water temperatures, hydraulic circuit, indoor emitters and controls to the actual building load.
Good hydronic design starts before equipment selection.
The first questions are not “which heat pump?” They are “what does the building need?” and “how will that energy be delivered?”
Typical water-temperature ranges
Fan coils: approximately 35–45°C for heating in the EVOHX technical material.
Radiators / towel rails: approximately 45–55°C in the same material.
Actual design temperatures depend on emitter selection, heat loss, comfort requirements and manufacturer data.
One loop or several?
The building determines the architecture. A small home and a multi-storey apartment building may use very different hydraulic arrangements.
Standalone
A smaller system can serve one dwelling with heating, cooling and domestic hot water from one outdoor heat-pump platform.
Central two-pipe
A central system can distribute water for heating or cooling and use a separate DHW service. The central space-conditioning mode is one at a time.
Four-pipe
Separate heating and cooling circuits can allow simultaneous heating and cooling, but this adds plant, controls and hydraulic complexity.
Storage is part of the design.
DHW storage should be selected from actual demand rather than simply choosing a tank size from a catalogue. Peak usage, recovery time, ring-main requirements and available plant space all matter.
EVOHX technical material identifies 300–500 litre storage as a typical range for one central arrangement, but project sizing must be confirmed from demand.
| Design item | Why it matters |
|---|---|
| Heat load | Determines required heating capacity. |
| Cooling load | Determines summer capacity and condensate requirements. |
| Water temperature | Influences emitter output and heat-pump performance. |
| DHW demand | Determines storage and recovery requirements. |
| Hydraulics | Determines flow, pressure loss, pump and pipe sizing. |
Bring us the building information.
Plans, floor areas, room use, heat-load information, emitter preferences and hot-water requirements give us the information needed to discuss a system properly.
Send project information