ISO/TC 163/SC 2/WG 15 - Energy Performance calculation methods

This document specifies procedures for the calculation of the energy needs for heating and cooling, internal temperatures and sensible and latent heat loads of a building according to the hourly calculation methodology in ISO 52016-1. Additions or modifications of the calculations are provided in this document if the building envelope contains one or more adaptive building envelope elements (building envelope elements with adaptive components that are either environmentally or actively controlled as a function of specific conditions). The adaptive building envelope element replaces the transparent building element in the calculation according to ISO 52016-1. The three types of adaptive building envelope elements covered in this document are: — building envelope elements with dynamic solar shading; — building envelope elements with chromogenic glazing; — building envelope elements with an actively ventilated cavity. Environmentally activated control is described for building envelope elements with chromogenic glazing, but can also occur for other types of adaptive building envelope elements. In that case the same approach applies as for environmentally activated chromogenic glazing. This document is applicable to the assessment of the energy performance of buildings (EPB) (energy performance labels and certificates), including comparison between buildings and checking conformity with minimum energy performance criteria. It is also applicable to assess the contribution of the adaptive building envelope element to the smart readiness of a building. In addition, this document provides indicators for the impact of the adaptive building envelope element on the performance of the building compared to a reference building envelope element. It is applicable to buildings at the design stage, to new buildings after construction and to existing buildings in the use phase. This document is not applicable to geometrically complex adaptive building envelope elements that can only be modelled as multiple coupled thermal zones. NOTE The background to the selection of adaptive building envelope elements is given in ISO/TR 52016-4.

ISO 52010-1:2017 specifies a calculation procedure for the conversion of climatic data for energy calculations. The main element in ISO 52010-1:2017 is the calculation of solar irradiance on a surface with arbitrary orientation and tilt. A simple method for conversion of solar irradiance to illuminance is also provided. The solar irradiance and illuminance on an arbitrary surface are applicable as input for energy and daylighting calculations, for building elements (such as roofs, facades and windows) and for components of technical building systems (such as thermal solar collectors, PV panels). Other parameters of climatic data needed to assess the thermal and moisture performance of buildings, building elements or technical building systems [like wind, temperature, moisture and long-wave (thermal) radiation] are to be obtained according to the procedures in ISO 15927‑4. These data are listed in ISO 52010-1:2017 as input and passed on as output without any conversion. NOTE 1 The reason for passing these data via ISO 52010-1:2017 is to have one single and consistent source for all EPB standards and to enable any conversion or other treatment if needed for specific application. NOTE 2 Table 1 in the Introduction shows the relative position of ISO 52010-1:2017 within the set of EPB standards in the context of the modular structure as set out in ISO 52000-1.

ISO/TR 52010-2:2017 contains information to support the correct understanding and use of ISO 52010‑1. ISO/TR 52010-2:2017 does not contain any normative provision.

ISO/TR 52018-2:2017 refers to ISO 52018‑1. ISO 52018‑1 gives a succinct enumeration of possible requirements related to thermal energy balance features and to fabric features. It also provides tables for regulators to report their choices in a uniform manner. ISO/TR 52018-2:2017 provides many background considerations that can help both private actors and public authorities, and all stakeholders involved, to take informed decisions. ISO/TR 52018-2:2017 does not contain any normative provision.

ISO 52016-1:2017 specifies calculation methods for the assessment of: a) the (sensible) energy need for heating and cooling, based on hourly or monthly calculations; b) the latent energy need for (de-)humidification, based on hourly or monthly calculations; c) the internal temperature, based on hourly calculations; d) the sensible heating and cooling load, based on hourly calculations; e) the moisture and latent heat load for (de-)humidification, based on hourly calculations; f) the design sensible heating or cooling load and design latent heat load using an hourly calculation interval; g) the conditions of the supply air to provide the necessary humidification and dehumidification. The calculation methods can be used for residential or non-residential buildings, or a part of it, referred to as "the building" or the "assessed object". ISO 52016-1:2017 also contains specifications for the assessment of thermal zones in the building or in the part of a building. The calculations are performed per thermal zone. In the calculations, the thermal zones can be assumed to be thermally coupled or not. The calculation methods have been developed for the calculation of the basic energy loads and needs, without interaction with specific technical building systems, and for the calculation of the system specific energy loads and needs, including the interaction with specific systems. The hourly calculation procedures can also be used as basis for calculations with more extensive system control options. ISO 52016-1:2017 is applicable to buildings at the design stage, to new buildings after construction and to existing buildings in the use phase. NOTE Table 1 in the Introduction shows the relative position of ISO 52016-1:2017 within the set of EPB standards in the context of the modular structure as set out in ISO 52000-1.

ISO 52017-1:2017 specifies the general assumptions, boundary conditions and equations for the calculation, under transient hourly or subhourly conditions, of the internal temperatures (air and operative) and/or the heating, cooling and humidification and dehumidification loads to hold a specific (temperature, moisture) set point, in a single building zone. No specific numerical techniques are imposed by ISO 52017-1:2017. Specific calculation procedures based on the generic calculation procedures of ISO 52017-1:2017 are given in ISO 52016-1. The specific simplifications, assumptions and boundary conditions in ISO 52016-1 are tailored to the respective application areas, such as the energy need for heating and cooling and for humidification and dehumidification, hourly internal temperature, design heating and cooling and humidification and dehumidification load. NOTE Table 1 in the Introduction shows the relative position of ISO 52017-1:2017 within the set of EPB standards in the context of the modular structure as set out in ISO 52000-1.

The set of EPB assessment standards produces a great number of overall and partial EPB indicators as outputs, which can be used for different purposes. ISO 52018-1:2017 deals with the use as requirement of partial EPB indicators related to the fabric and related to the thermal balance of the building. Thermal balance aspects concern both the heating and cooling needs and the free floating temperatures, especially with respect to overheating or too cold indoor temperatures. ISO 52018-1:2017 can support both private parties and public regulators (and all stakeholders involved in the regulatory process) with the "post-processing" of these outputs. ISO 52018-1:2017 provides standardized tables for reporting, in a structured and transparent manner, the choices that are to be made with respect to the partial EPB requirements covered by ISO 52018-1:2017. The tables are non-restrictive, thus allowing for full regulatory flexibility. NOTE Table 1 in the Introduction shows the relative position of ISO 52018-1:2017 within the set of EPB standards in the context of the modular structure as set out in ISO 52000-1.

ISO/TR 52016-2:2017 contains information to support the correct understanding and use of ISO 52016‑1 and ISO 52017‑1. These documents give calculation methods for the assessment of: - the (sensible and latent) energy load and need for heating and cooling, based on hourly calculations; - the (sensible and latent) energy need for heating and cooling, based on monthly calculations (ISO 52016‑1); - the internal temperature, based on hourly calculations; and - the design (sensible and latent) heating and cooling load, based on hourly calculations. ISO/TR 52016-2:2017 does not contain any normative provisions. NOTE A description of the rationale behind the reorganization of the cluster of strongly related and partly overlapping ISO and CEN standards is given in Annex H.