scope:

Scope and purpose

This guideline applies to the designing of free heating surfaces for water-based heating systems in residential, office and other buildings where day rooms are used similarly. This guideline aims at establishing a set of requirements including comfort and efficient use of energy, which means exceeding the simple aim of just covering the required design heating load. Three different classes of requirements allow determining, and limiting, the scope of functions of the free heating surface to be designed, depending on the application. This serves to avoid that the highest class can be claimed as a matter of principle. The restriction to free heating surfaces is not intended to indicate that other room heating systems do not achieve the classes of requirements described here.

The effect of forced ventilation by means of fans on the air flow in a room is not covered in this guideline. Designing includes the following steps: 

• firstly, the determination of the location where the free heating surface is to be installed, selection of the appropriate type, dimensioning of the visible surfaces, and the calculation of the mean heatingsurface excess temperature, 

• secondly, the calculation of the inlet and outlet water temperatures, water flow rate, and standard thermal output of the heating surface, taking into account the design heating load and a specified heating-up reserve 

• thirdly, the selection of the appropriate heatingappliance model.