INTERNA heat pump units are particularly suitable for indoor installation.

They are fitted with EC centrifugal fans that guarantee low noise.

That have been designed to be ducted towards the outside and are equipped with a Scroll EVI inverter compressor.

The units have been designed with renovations in mind where it is important not to modify the aesthetic appearance of buildings (historic buildings, architectural constraints etc.).

The unit is suitable for operation in harsh climates and the vapour injection technology used in the Scroll compressor ensures system delivery temperatures of greater than 50°C.

The INTERNA heat pump has the following characteristics:

  • Energy efficiency A++;
  • Minimum working temperature -25°C;
  • Scroll EVI Inverter compressor;
  • Siemens controller capable of managing the entire thermal system;
  • Electronic expansion valve;
  • Extremely silent;
  • EC centrifugal fan;
  • Modulating circulation pump;
  • Remote control via cable and Wi-Fi;
  • Possibility of connecting to the Internet via a webserver;
  • Extremely robust and resistant to wear.
[lvca_tabs style="style4" highlight_color="#e06223" mobile_width="600"][lvca_tab tab_title="Data Sheet"]

PERFORMANCE Output [ kW ] / Input [ kW ] COP
A7/W35 1) 2,7 - 11,4 5,7 - 21,5
A7/W35 1) 3,4 / 0,8 / 4,3 7,1 / 1,6 / 4,6
A2/W35 1) 2,7 - 11,4 5,7 - 21,5
A2/W35 1) 3,7 / 1,1 / 3,4 7,6 / 2,1 / 3,7
A-7/W35 2,3 - 8,5 4,8 - 17,1
A7/W35 4,0 / 1,3 / 3,1 8,0 / 2,5 / 3,2
A7/W55 - 3,5 - 11,5 7,2 - 21,8
A7/W55 4,3 / 1,6 / 2,7 9,0 / 3,0 / 3,0
A2/W55 3,3 - 11,0 6,7 - 21,0
A2/W55 4,7 / 1,8 / 2,6 9,5 / 3,4 / 2,8
A-7/W55 2,9 - 8,9 6,1 - 17,8
A-7/W55 5,1 / 2,3 / 2,2 10,0 / 4,1 / 2,4
Energy Efficiency class 2) A++ (A+++ after 2019)
Energy efficiency class 55°C A++
Operating limits of outside air [°C] °C - 25 ÷ + 40
Heating delivery temperature limit min / max. [°C] 20 ÷ 65 (A -10)
Hydraulic connections delivery/return G1”
Nominal heating side flow rate with dT 5°C [m3*h-1] 1,2 2,4
Minimum heating side flow rate at dT 7°C [m3*h-1] 0,8 1,7
Pressure drop [KPa] 4 13
Flow coefficient Kvs 6 6,7
Anti-freeze function Si
Air flow rate [m3*h-1] 4500 4500
Expansion valve Electronic
EVI liquid coolant injection system Yes
Refrigerant type R410A
Defrosting Automatic
Coolant load [kg] 4 5
Defrost type Hot Gas
Condensate collection tank heating Residual heat
Condensate drain diam. [mm] 40
Pressure switch high pressure cut-off [MPa] 4,5 4,5


Width x depth x height [mm] 1060 x 759 x 1810 1060 x 759 x 1810
Weight [Kg] 270 270
Mounting Indoor
Outer casing Yes
Rated voltage 3x230/400V AC, 50Hz
Compressor Variable speed Scroll EVI
Rated current A7 / W35 [A] 3,1 4,4
Maximum current [A] 4,7 6,6
Starting current [A] Ramps Ramps
Starting current with soft starter - -
Fuse with soft starter 16B/3 16B/3
Electrical protection Inverter + extra
Compressor power cable CYKY [n x mm2] 5 x 2,5 (no of bivalent) 5 x 4(no of bivalent)
Safety rating IPX (EN60 529) 43 43
Sound power level LWA [dB] 53 53
Sound pressure level at LpA 5 m [dB] 34 34
EC fan 450 mm
Fan speed regulation Signal 0-10V
Electrical panel Indoor
Electric heater Optional
Circulation pump UMP3 25-70
Controller AVS37 / QAA74
Siemens regulator RVS61
Display QAA75 / QAA55
External sensor QAC34
Phase control Standard
Control via the Internet Yes - webserver option
Cascade Optional - up to16 CV
Modbus Communication Yes - Modbus option

1) In accordance with European standard EN 14511.
2) In accordance with European standard EN 14825 for temperate climates.
4) Operating air temp. 35°C and system delivery +7°C. (According to European standard EN 14511).[/lvca_tab][lvca_tab tab_title="Features"]


Technical specifications
Compact air-water heat pump with a ducted centrifugal fan and Scroll EVI inverter compressor for indoor installation, with
a cutting-edge design and high COP. The heat source is the outside air up to a minimum of -25°C. Low noise is guaranteed by the use of a Scroll EVI compressor that doesn’t use traditional pistons and valves, the use of anti-vibration mountings, by a solid, compact and reinforced base plate, multi-layer noise insulation on the cover and above all a centrifugal fan.

The Siemens control unit (AVS37) can be combined with a QAA78 wireless unit (optional) which is a combined device for
space heating and DHW. The controller allows direct connection to the heating system with or without a storage tank, or
more commonly, by connecting the latter to the heating system at two or four points. The controller also allows an auxiliary
boiler to be controlled. The storage tank can be charged at a constant temperature and from a bivalent source:
• Auxiliary electric heaters in the circuit or storage tank
• Auxiliary external sources (existing gas, electric and other boilers)
• Bivalent control in one or three phases.
The heating system can be controlled both equithermally and according to the room temperature. The standard regulation
can cascade up to 16 units or other sources that are already available at standard regulation.
The speed of the compressor, fan and circulators is continuously regulated by the control unit.

Construction details
The units are made of powder coated hot-dip galvanized sheet metal; the structure is self-supporting with removable panels
to make inspection and maintenance easer.

Cooling circuit
The refrigerant gas used is R401A and the expansion valve is electronically controlled.

Heat exchangers
The source side heat exchangers are made of copper tubes and aluminium fins. The user side braze-welded plate exchanger
allows the amount of refrigerant gas to be reduced to the minimum. The system delivery and return connections are G1”.

The EC centrifugal fan has been designed to minimize noise and to maintain an adequate head in the ducts.
Control and protection The unit is equipped with a series of alarms designed to draw attention to anomalous values. These are managed entirely by the control unit that makes them available. It is also possible to access the controller via the control unit if you need to
make any adjustments.[/lvca_tab][lvca_tab tab_title="Quote"]

Contact us for  a quote


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