Notes on Nilan Compact P2 GEO3 Polar

It is a single unit for ventilation with heat recovery and a heat pump against the exhaust air for heating or cooling the incoming air and producing domestic hot water, and another heat pump against ground loop for additional heating or cooling.

Nilan Compact P2 ventilation crossflow heat exchanger
Nilan Compact P2 ventilation crossflow heat exchanger with a heat pump against the outgoing air for heating and hot water production.


Here are the components for this particular unit (inspected manually or extracted from the available documentation). Note that different production runs might be using different components.

Air Filters

Nilan Greencycle filter (G4, ISO Coarse > 75%).

Supply and Extract Air Motors

D190mm Not confirmed, yet.

Pre-Heating Element (Polar)

RDT TW3 1500W 240V resistive heater coil in the back of the top-left incoming air chamber.

Counter-flow Air Heat Exchanger

Holtop 3D crossflow heat exchanger

Polyethylene terephthalate (PET) counterflow heat exchanger. Potentially Holtop 3D (specification PDF).

Bypass Damper

Belimo CM230-F rotary actuator (orange device in the middle of the photo) controls the bypass damper — the cover for the cross-flow heat exchanger (the aluminium plate covering the green cross-flow heat exchanger in the top-left) and the square opening (to the right of the actuator) in the middle of photo connecting the incoming and outgoing air chambers.

Air-Source Heat Pump

Danfoss SC15GHH reciprocating compressor pumps the heat from the exhaust air (bottom left) to either the hot water tank or the incoming air. It is a high back pressure (HBP) compressor with a high condenser temperature of 55C to ensure it can heat up the domestic water using the R134a refrigerant.

It’s heat output ranges from 345W at -15C evaporator (is that the outgoing air after the counter-flow heat exchanger?) temperature (COP 1.26) to 1731W at 15C evaporator temperature (COP 3.02) at EN12900/CECOMAF rating conditions:

Evaporator Temperature, CCapacity, WPower Consumption, WCOP

which looks like this on a chart:

SC15GHH heat pump capacity, power consumption and COP
SC15GHH heat pump capacity, power consumption (left axis) and COP (right axis).

Prices online range from EUR 150 to 900.

CO2 Sensor (Optional)

Korea Digital SenseCube KCD-AN300 CO2 sensor

Korea Digital SenseCube KCD-AN300 (RS-15-spec) (sold by Nilan) with dual-wavelength NDIR sensor with 4-20mA / 0-10V analog or RS485 / PWM output.

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