Scope of the program

This programme applies to selected ranges of Air Handling Units. Each range shall at least present one size with a rated air volume flow below 3 m3/s. 

Since 2020, all certified companies (as well as new applicants) shall certify all their products as long as they fall under the scope of the AHU programme (Certify All).

All Real Unit sizes in the range up to the maximum stated air flow shall be declared. All Model Box configurations shall be declared.

Ranges without at least one size with a rated air volume flow below 3 m3/s are excluded.


Air Handling Unit: A factory made encased assembly or flat-packaged unit that consists of a fan or fans and other necessary equipment to perform one or more of the following functions: circulating, filtration, heating, cooling, heat recovery, humidifying, dehumidifying and mixing of air. The unit should be suitable to be used with ductwork.

Range: A family of Air Handling Units of different sizes grouped under the same designation and using the same selection procedure.

Main Range: One or several ranges which represent either the most important turnover or the most sold ranges in terms of units falling in the scope of the programme.

Model Box: Construction envelope built according to specifications presented in manufacturer’s literature, used to establish mechanical, thermal and acoustical performance according to the relevant EN standards.

Real Unit: Unit from the range of a specific size, used to establish complete performance for all the available functions of the Air Handing Unit range, according to the relevant EN standards.

Sub-range: Part of a range using the same Model Box(es) and grouped under the same designation.

Deflection [mm/m]: The largest deformation of the sides of the unit under pressure, positive or negative, given as a difference in distance from a reference plane outside the unit to the external unit surface with and without test pressure. The deflection, related to the span, defines the casing strength.

Air leakage factor [l.s-1.m-2]: The air leakage in volume per unit of time, related to the external casing area.

Thermal transmittance [W.m-2.K-1]: The heat flow per area and temperature difference through the casing of the air handling unit.

Thermal bridging factor [-]: The ratio between the lowest temperature difference between any point on the external surface and the mean internal air temperature and the mean air-to-air temperature difference.

Filter bypass leakage [%]: Air bypass around filter cells as a percentage of rated air volume flow.

Acoustical insulation [dB]: Sound insertion loss value of the Air Handling Unit.

Heating capacity [kW]: Thermal energy supplied into the air per unit of time.

Cooling capacity [kW]: Thermal energy removed from the air per unit of time.

Heat recovery [%]: Heat transferred from exhaust air into supply air or reverse.

In-duct sound power level [dB]: Sound power level per octave band, radiated in the duct.

Airborne sound power level [dB(A)]: Sound power level radiated through the envelope of the Air Handling Unit.

Certified characteristics

Mechanical characteristics 

The following mechanical characteristics are certified : 
a - Casing strength (CS)
b - Casing air leakage (CAL)
c - Filter bypass leakage (FBL)
d - Thermal transmittance of the casing (TT)
e - Thermal bridging factor (TBF)
f - Acoustical insulation of casing 

Performance characteristics 

The following mechanical characteristics are certified : 
a - Air flow - Available static pressure - power input 
b - Octave band in-duct sound power level 
c - Airborne sound power level 
d - Heating capacity* 
e - Cooling capacity* 
f - Heat recovery* 
g - Pressure loss on water side* 

* If standard features of the product range

Certification manual


TCR (Technical Certification Rules)