11.09.2024

How to calculate the size of radiators needed using the heat rate calculator?

Most radiator manufacturers offer radiator heat capacity calculators that make this task much easier. The aim of this article is to help you understand what information is needed to use the calculator and to learn its functions. The calculator will be used as an example for Termolux radiators, which are high-quality plate radiators that we also stock, but it is worth mentioning that there is little difference in overall functionality between them. 

In order to calculate the dimensions of the radiator as accurately as possible, the following information is required, without which the calculation is not possible. If a heating system is designed or at least a rough layout of the radiators is prepared, this information will be available and can also be obtained through a rough heat calculation:

• Required heat output to heat the space (based on the heat input calculation or assuming an approximate output based on the existing thermal insulation);
• Heating return and return temperatures, °C (depending on heating source and system);
• Preferred room temperature, °C.

By entering this information into the heating system calculator, it is also possible to know the difference between the temperature of the heat transfer medium and the room temperature, or ∆T:

The resulting radiator table shows the heat output data - the power that each radiator theoretically delivers to the room at these parameters. Then all that is left to do is to equate the power required by the room to the nearest value in the radiator table (where you can see the length, the height and the width or type of radiator). For example, to heat a room that requires 1500W at the above parameters, a 22x1100x450 or 22x1100x500 radiator would be most suitable, or if the project requires several radiators, two 22x500x550 radiators.

Below you can find a link to the Termolux radiator selection calculator.

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