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Dual Fluid System
Certification manual
Certification manual
Technical Certification Rules


The Eurovent Certified Performance (ECP) programme scope for Dual Fluid System (DFS) applies to systems with a cooling capacity above 12 kW, declared and published as combination of outdoor and the heat transfer unit according to the testing limits. Used in cooling-only, heating-only and reversible DFS systems. 

Heat recovery units are included in the scope, but the heat recovery function is not certified. 

The program covers all DFS systems from standard production with a cooling and heating capacity in standard conditions as given in the table below.

Table 1: Testing limits for certified units

Capacity Number of connected indoor units
Ducted horizontal Cassette Wall mounted Ceiling suspended
12 <  P <  30 kW (in both modes) 4 4 / /
30 (in one mode) ≤ P < 50kW (in both modes)  6 4 6 6
50 (in one mode) ≤ P < 100 kW (in both modes) 6 4 6 6


For the full programme scope and exclusions please see the Technical Certification Rules.


Whenever a company participates in the programme for DFS systems, all DFS outdoor units that are promoted by the applicant/participant to end-users, specifiers, trading companies, contractors by means of paper or electronic catalogue, price list or software within the scope of the programme, shall be certified. This is done in accordance with the Technical Certification Rules and includes all models in modular ranges. For the DFS programme, the certify-all requirement as defined in the Certification Manual is applicable.


The Dual fluid systems in the DFS programme can used for heating only, cooling only, or heating and cooling in buildings. Units can be used in a wide range of residential and commercial applications.

A dual fluid system is defined as a system that uses an inverter technology to control the refrigerant volume of a chiller for the outdoor unit and circulated water for the indoor units. The chiller systems applicable for the programme are air cooled systems.

Outdoor and indoor units are connected through a heat transfer unit controller. The heat transfer unit controller controls the outdoor unit based on the demand from the indoor units. 

The indoor units can be of various types including:

  • Cassette
  • Ducted
  • Wall mounted
  • Ceiling suspended. 


Nominal Efficiencies

  • Outdoor cooling capacity at standard conditions
  • Outdoor heating capacity at standard conditions
  • Energy Efficiency Ratio (EER) in Cooling
  • Coefficient of Performance (COP) in heating
  • LRcontminc and CcpLRcontminc (optional)
  • LRcontminh and CcpLRcontminh (optional)

Seasonal Efficiencies for Cooling

  • Pdesignc
  • SEER for each declared climate
  • ηsc
  • Auxiliaries (Pto, Pck.) for cooling mode
  • Part loads (Capacities & Efficiencies)

Seasonal Efficiencies for Heating

  • Pdesignh
  • SCOP for each declared climate
  • ηsh
  • Climat Auxiliaries (Pto, Pck, .), Heating mode
  • Part loads (Capacities & Efficiencies), for each declared climate


  • Sound power level in cooling / heating
  • Sound power level in heating (only for reversible DFS)
    • Cassette units: Overall A-weighted outdoor/indoor side sound power level
    • Ducted units: Overall A-weighted sound power level radiated from the duct.

Apply for the Dual Fluid System programme

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