NA 044

DIN Standards Committee Refrigeration Technology


Roof-top units


document specifies the terms and definitions, the test conditions and the test methods of air-sourced and water-cooled roof-top units, driven by electric compressor(s), which may be equipped with a supplementary heater using electrical resistance or combustion of fossil fuel. This document covers roof-top units with 2, 3 or 4 dampers, including several features as the free-cooling, mixing air flows (on both sides) and heat recovery. This document deals with roof-top units providing space heating and/or cooling for comfort application. Process applications are not covered by this document. This document provides the part load conditions and the calculation methods taking into account roof-top units features for the determination of seasonal energy efficiency SEER and SEERon, seasonal space cooling energy efficiency ηs,c, seasonal coefficient of performance SCOP, SCOPon and SCOPnet, seasonal space heating energy efficiency ηs,h and the overall annual efficiency. Such calculation methods may be based on calculated or measured values. In case of measured values, this document covers the test methods for determination of capacities, EER and COP values during active mode at part load conditions. It also covers test methods for the determination of power input during thermostat-off mode, standby mode, off-mode and crankcase heater mode. A roof-top unit that is not using at least the thermodynamic cycle for space heating is considered as a cooling only unit. Roof-top units equipped with additional air heating and/or cooling heat exchangers will be rated without operation of these heat exchangers.





Planned document number

DIN EN 17625

Project number


Responsible national committee

NA 044-00-06 AA - Heat pumps with electrically driven compressors and air conditoners  

Responsible european committee

CEN/TC 113/WG 15 - Roof-top units  

draft standard

Roof-top units; German and English version prEN 17625:2020
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