Delta-T (ΔT)
Delta-T (ΔT) is used to calculate BTU and kW ratings for radiators.
The Delta-T number is the difference between the ambient air temperature and the water temperature inside the radiator.
In the UK we follow the current European regulations on energy conservation and so use Delta-T50.
The older Delta-T60 is now obsolete and would give an inflated BTU or kW rating.
e.g. Delta-T50 is based on the mean water temperature of 70C and the universally quoted standard 20C room air temperature.
75C radiator inlet + 65C radiator outlet = 140C
140C / 2 = 70C
70C - 20C = 50C
The Delta-T number is the difference between the ambient air temperature and the water temperature inside the radiator.
In the UK we follow the current European regulations on energy conservation and so use Delta-T50.
The older Delta-T60 is now obsolete and would give an inflated BTU or kW rating.
e.g. Delta-T50 is based on the mean water temperature of 70C and the universally quoted standard 20C room air temperature.
75C radiator inlet + 65C radiator outlet = 140C
140C / 2 = 70C
70C - 20C = 50C
