What is ISO 11855-2 about?
ISO 11855-2 is the second part of multiple series that specifies procedures and conditions to enable the heat flux in water-based surface heating and cooling systems to be determined relative to the medium differential temperature for systems.
ISO 11855‑2 provides steady-state calculation methods for determination of the heating and cooling capacity.
NOTE-
The panel system with the open-air gap, which is not integrated with the building structure, is not covered by this series.
The ISO 11855 series is not applicable for the testing of systems. The methods do not apply to heated or chilled ceiling panels or beams
Who is ISO 11855-2 for?
ISO 11855-2 on embedded radiant heating and cooling systems is useful for:
- Construction industry
- Civil engineer
- Architect
- Manufacturer installer or supplier of building material
- Building contractor, operator, investigator, manager
Why should you use ISO 11855-2?
The radiant heating and cooling system consist of heat-emitting/absorbing, heat supply, distribution, and control systems. Heat flux can be defined as the rate of heat energy transfer through a given surface, and heat flux density is the heat flux per unit area. The objective of ISO 11855 series is to provide criteria to effectively design embedded systems. To do this, it presents comfort criteria for the space served by embedded systems, heat output calculation, dimensioning, dynamic analysis, installation, control method of embedded systems, and input parameters for the energy calculations.
ISO 11855-2 specifies the comfort criteria that assists you in designing embedded radiant heating and cooling systems, since the main objective of the radiant heating and cooling system is to satisfy thermal comfort of the occupants.
The determination of the thermal performance of water-based surface heating and cooling systems and their conformity to ISO 11855-2 is carried out by calculation in accordance with design documents and a model. This enables you to ensure a uniform assessment and calculation of water-based surface heating and cooling systems.
ISO 11855-2 provides steady-state calculation methods which helps you in determination of the heating and cooling capacity. You can determine the heating system by linear thermal resistances. In this way, the important parameters for the heat transfer are highlighted. In addition, a clear distinction is made between the heat transfer in the structure and the heat transfer between surface and space. However, you can verify some of the equivalent resistances by determining numerical calculation general method based on finite element analysis (FEA) or finite difference methods (FDM) calculation methods depending on the position of pipes and type of building structure
What’s changed since the last update?
ISO 11855-2:2021 supersedes ISO 11855‑2:2015, which is withdrawn.
This second edition cancels and replaces the first edition (ISO 11855-2:2012), which has been technically revised.
The main changes compared to the previous edition are as follows:
- Update of the figures for type A and C,
- Update of the thermal, relevant material characteristics,
- Editorial corrections