Most of the time, the heat recovery process occurs via a high-efficiency counterflow heat exchanger that achieves 85 – 95% heat recovery. The unit is also equipped with an air to air heat pump that can heat the supply air when the dwelling requires heating. In some low energy houses Combi 302 Polar is the primary heat source, but it can also control external, supplementary heat sources such as electric radiators.

The heat pump has a reversible cooling circuit and it can therefore also cool the supply air with up to 14 ºC when necessary during the summer. Combi 302 Polar is not comparable with an air conditioner.

The cooling effect of the unit is not as substantial, which is due to its low level of air exchange of approx. 0.5 times/hour. But when the outdoor air is cooled down, it will condense, and the cooler air that is led into the dwelling is therefore less humid. Low air humidity makes it easier to cope with a high indoor temperature. We therefore call it “Comfort cooling”. 

*1 – At ± 250 Pa and 300 m3/h according to EN 13141-7.
*2 – At ± 100 Pa and 300 m3/h according to EN 13141-7.

ATTENTION! When positioning the unit, you should always consider future services and maintenance. It is recommended that you leave a minimum of 60 cm of clear space in front of the unit.

It must be easy to replace filters and it must be possible to replace, for instance, fans and other components.

ATTENTION! The unit must be level to enable proper drainage from the condensate tray.

The unit makes little noise and produces only weak vibrations, but you should still take into account potential vibrations that can spread from the unit to individual building components. In order to separate the unit from its foundation, it is therefore recommended that you install vibration absorbers under the unit. There should be approx. 10 mm distance to other building components and to permanent fixtures.

Capacity

Capacity of standard unit as a function of qv and Pt, ext.

SEL values according to EN 13141-7 are for standard units with ISO Coarse >75% (G4) filters and without heating element. 

SEL values comprise the unit´s total power comsumption incl. control.  

Conversion factor: J/m³: 3600 = W/m³/h.

Attention! The SEL values are measured and stated as a total value for both fans.

Temperature efficiency

Temperature efficiency for units with counterflow heat exchanger according to EN308 (dry).

Temperature efficiency EN308: ɳt = (tsupply air-tfresh air)/(textract air-tfresh air)

COP (heating)

Heat effect factor COP [-] supply air as function of outdoor temperature [°C] and volume flow qv [m3/h].

According to EN14511, extract air = 21°C.

COP (heating)

Heat effect factor COP [-] supply air as function of outdoor temperature [°C] and volume flow qv [m3/h].

According to EN14511, extract air = 21°C.

Heat effect (supply air)

Heat effect Qc [W] as a function of qv [m3/h] and fresh air temperature [°C]. 

According to EN 14511, extract air = 21 °C 

The fixed curves indicate the total heat recovery at different outdoor temperatures, where the dotted line indicates the heat supplied to the supply air (heat output).

The difference between the fixed curves and the dashed curves corresponds to the ventilation loss covered by the heat pump and the heat exchanger.

Supply air temperature (heating)

Supply air temperature [°C] as a function of fresh air temperature [°C] and volume flow qv [m3/h] balanced flow. 

Extract air temperature = 21 [°C],  45 RH [%] 

Supply air temperature (cooling)

Supply air temperature [°C] as a function of fresh air temperature [°C] and volume flow qv [m3/h] balanced flow.

Extract air temperature = 24°C

Sound data

Sound data for qV = 210 m3/h and Pt, ext = 100 Pa according to EN 9614-2 for surfaces and EN 5136 for ducts.

Sound output level LWA drops with falling air volume and falling back pressure.

Sound output level LpA at a given distance will depend on acoustic conditions in the place of installation.