BS EN442

As from 1 July 2003, all catalogued outputs must be displayed at 50oC temperature difference. This is a change from the previous standard BS 3528 which stipulated that catalogue outputs were to be stated at 60oC temperature difference. This is a European legislation, ensuring all European radiator manufacurers are working from the same reference point, which is based on the following temperatures:

Flow Temperature

75oC

Return Temperature

65oC

Air Temperature

20oC

The calculation is done:

Flow + Return
2 - Air Temperature = Temperature Difference

75 + 65
2 - 20 = 50oC Temperature Difference

The previous Temperature difference of 60oC was calculated using:

Flow

90oC

Return

70oC

Air

20oC

This standardises outputs for radiator selection, and although with this new standard radiator outputs may appear to be lower, the physical outputs of the radiators remain the same.

To convert outputs at 50oC temperature difference to outputs at 60oC temperature difference multiply by 1.267.