Water-to-water heat pump THERMIA CALIBRA E 8 DUO (WW) – 2–8 kW, up to 65 °C, without DHW cylinder

Product detailed description

The THERMIA CALIBRA E 8 DUO WW (code IHP203646WW) is an inverter heat pump in the water-to-water version. Well water passes its heat to the brine circuit in the supplied plate heat exchanger and is then returned to a soakaway well. The DUO model has a lower cabinet (1450 mm) without a cylinder – hot water is produced in a separate cylinder, such as the free-standing stainless steel MBH TWS. The CALIBRA E range is designed for buildings with heat losses up to 24 kW.

Key features

• inverter-controlled Copeland scroll compressor and variable-speed circulation pumps – output adapts continuously to the home's demand within 2–8 kW
• flow temperature up to 65 °C, suitable for underfloor heating and radiators
• R452B refrigerant with GWP 698 (charge 0.9 kg), stainless steel plate heat exchangers
• COP 4.6 at B0/W35 (EN 14511), energy class A+++ at 35 and 55 °C
• the supplied plate heat exchanger needs a well water flow of 0.58 l/s at ΔT 3 K, with a pressure drop of 40 kPa
• GENESIS control with colour touch screen, built-in web server for Thermia Online, Modbus for building management and Smart Grid function for photovoltaics
• anti-vibration flexible pipes built into the cabinet – no external flexible hoses needed

System expansion

On the WW version the EM3 expansion card is already included, so the heat pump can control a mixed circuit, an external auxiliary heat source, an activated buffer tank and pool heating. The submersible well pump is ordered separately; for economical operation, the manufacturer recommends controlling it with a frequency converter.

Sizing and installation

Output is sized with the Thermia HPC software. The heat pump is placed in a frost-free room on a solid base, ideally a concrete floor, and not in a corner. The brine circuit is filled with a water-ethanol mixture with a freezing point of -17 ± 2 °C, a magnetic dirt separator with filter is fitted in the heating return, and the system must contain at least 14 l of water per kW of minimum output. The IVAR.TER-PS connection fitting (IHP08645678) is ordered separately. Installation and commissioning are for a qualified company, electrical work for an electrician and work on the refrigerant circuit for a qualified refrigeration technician.

Technical data

Frequently asked questions

What kind of house is the CALIBRA E 8 DUO heat pump suitable for?
The model operates within 2–8 kW with water up to 65 °C, so it suits underfloor heating and radiators in new builds and renovations. The exact output is determined with Thermia HPC based on the house's heat loss.

What is included in the delivery?
Besides the 9 and 3 bar safety valves, outdoor sensor, expansion vessel and filling unit for the brine circuit, the WW version also includes the built-in heat exchanger, flow sensor and EM3 card. The IVAR.TER-PS connection fitting (IHP08645678) and the DHW cylinder are ordered separately.

Is the well pump included?
No, the submersible well water pump is ordered separately. At ΔT 3 K this model needs a well water flow of 0.58 l/s.

Can the heat pump be controlled remotely?
Yes, the built-in web server allows control and monitoring via Thermia Online from a smartphone, tablet or computer. The Smart Grid function also enables operation with a photovoltaic system.