Two classes : winter & summer

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Winter class

The winter class takes into account the geographic location of the AHU. This location allows retrieving standard AHU sizing data (ASHRAE database).

These data must be used in the calculation of the Energy Efficiency Class under winter conditions.

They may differ from the sizing data requested by the customer. Our LST (Hydronic software) allows this distinction.

The main parameters considered in the calculation of the energy efficiency class are:

• Air velocity class in the AHU

• Heat recovery efficiency

• Pressure drop of the heat exchanger

• Efficiency of the fan-motor unit

There are six efficiency classes, from A+ to E.

In determining the energy efficiency class, AHUs are divided into three groups:

• Group 1: AHUs with a winter reference temperature ≤ 9°C (A+ to E)

• Group 2: AHUs with a winter reference temperature > 9°C (A+↪ to E↪)

• Group 3: Extractors (A+↑ to E↑)

Displaying the winter energy efficiency class on the selection sheet is mandatory, preferably as a label.

The “2016” under the class logo indicates that it refers to winter conditions.

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Summer class

The summer class also takes into account the geographic location of the AHU. This location allows retrieving standard AHU sizing temperature and humidity data (ASHRAE database). The calculation of the summer class also considers winter conditions.

These data must be used in the calculation of the energy efficiency class.

They may differ from the sizing data requested by the customer. The LST (Hydronic software) allows this distinction.

The main parameters considered in the calculation of the summer energy efficiency class are:

• Moisture recovery

• Reduction of pressure drop due to a bypass on the energy recovery units

(In the future, the effect of adiabatic cooling will also be integrated.)

In determining the summer energy efficiency class, AHUs are divided into three groups:

• Group 1: if one of the three conditions below is met (A+ to E)

  • Winter dry-bulb temperature ≥ -3°C and summer dry-bulb temperature ≥ 30°C

  • Winter dry-bulb temperature ≥ -3°C and dew-point temperature ≥ 17°C

  • Summer dry-bulb temperature ≥ 30°C and dew-point temperature ≥ 17°C

• Group 2: for all other cases (A+↪ to E↪)

• Group 3: Extractors (A+↑ to E↑)

For Group 1, the summer energy efficiency class is calculated according to Eurovent-specific formulas (summer group logo).

For Group 2, the summer energy efficiency class is identical to the winter class but with the logo corresponding to the summer group.

For Group 3, no calculation is performed; the summer energy efficiency class is identical to the winter class.

Displaying the summer energy efficiency class on the AHU selection sheet is mandatory for Group 1, preferably as a label.

It is optional for the other groups, and we have chosen not to display them.

The “2023” under the class logo indicates that it refers to summer conditions.

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