CEN/TC 156/WG 7 - System performance

The scope of this European Standard is
-   To define the procedure how the calculation methods to determine the temperatures, sensible loads and energy demands for the rooms shall be used in the design process.
-   To describe the calculation methods to determine the latent room cooling and heating load, the building heating, cooling, humidification and dehumidification loads and the system heating, cooling, humidification and dehumidification loads.
-   To define the general approach for the calculation of the overall energy performance of buildings with room conditioning systems
-   To describe one or more simplified calculation methods for the system energy requirements of specific system types, based on the building energy demand result from prEN ISO 13790, and to define their field of application.
A general framework standard is given which imposes an hourly calculation for all cases which cannot be covered by simplified methods, and gives requirements on what has to be taken into account. Input and output data are defined.
The target audience of this standard is twofold:
-   Designers of HVAC systems, which are given an overview of the design process with the relevant references to the different involved standards (Clauses 5 to 12)
-   Developers of regulations and tools, which find requirements for calculation procedures to be used for the energy requirements according to the EPBD (Clauses 13 and 14).
The idea followed by this standard is, that for the detailed approach one single calculation method is used for the different room related purposes such as room temperature calculation, room cooling and heating load calculation, and room energy calculation. This means, for the building type envisaged (buildings with room conditioning systems) it is an alternative to simplified calculation methods such as heating load according to EN 12831 and heating energy according to prEN ISO 13790. This standard does not describe any detailed methods for the sensible room based

This European Standard describes the method to calculate the ventilation air flow rates for buildings to be used for applications such as energy calculations, heat and cooling load calculation, summer comfort and indoor air quality evaluation.
The ventilation and air tightness requirements (as IAQ, heating and cooling, safety, fire protection…) are not part of the standard.
For these different applications, the same iterative method is used but the input parameter should be selected according to the field of application. For specific applications a direct calculation is also defined in this standard. A simplified approach is also allowed at national level following prescribed rules of implementation.
The method is meant to be applied to:
-   Mechanically ventilated building (mechanical exhaust, mechanical supply or balanced system).
-   Passive ducts.
-   Hybrid system switching between mechanical and natural modes.
-   Windows opening by manual operation for airing or summer comfort issues.
Automatic windows (or openings) are not directly considered here.
Industry process ventilation is out of the scope.
Kitchens where cooking is for immediate use are part of the standards (including restaurants..)
Other kitchens are not part of the standard.
The standard is not directly applicable for buildings higher than 100 m and rooms where vertical air temperature difference is higher than 15K.
The results provided by the standard are the building envelope flows either through leakages or purpose provided openings and the air flows due to the ventilation system, taking into account the product and system characteristics.

TC - Deletion of "commercial" in the title according to TC Resolution 510 from 2010-11-24 - Heating, cooling, ventilation and air conditioning - Others

This European Standard describes the method to calculate the energy impact of ventilation systems (including airing) in buildings to be used for applications such as energy calculations, heat and cooling load calculation.
Its purpose is to define how to calculate the characteristics (temperature, humidity) of the air entering the building, and the corresponding energies required for its treatment and the auxiliaries electrical energy required.
This standard can also be used for air heating and cooling systems when they assure the provision of ventilation, considering that prEN 15243 will provide the required heating or cooling load and the corresponding air flows and/or air temperatures.

This document applies to the design of ventilation and room conditioning systems for non-residential build-ings subject to human occupancy. It focuses on the definitions of the various parameters that are relevant for such systems. Naturally ventilated buildings are outside the scope of this document.
The classification uses different categories. For some values, examples are given and, for requirements, typical ranges with default values are presented. The default values given in this document shall be used where no other values are specified. Classification should always be appropriate to the type of building and its intended use, and the basis of the classification should be explained if the examples given in the standard are not to be used. National regulations must always be followed, even when they are out of the range given in this document.