FARAL Aluminium radiators LINK have been installed in the UK since 1966 and are still regarded as the most efficient radiator on the market today.
The elegant but practical Italian design and construction of the FARAL Aluminium radiators provide excellent conduction of heat which means that they give up there heat more quickly than steel radiators to reach the room temperature required much faster especially in a low water temperature central heating system.

If you are installing a heat pump or another renewable energy low water temperature heat source into a new system using your existing radiators then you must check the heat required for the room matches the KW output of your radiator at a lower water temperature.

The general rule is that if the radiator outputs in an older central heating system were sized using a boiler supplying water at 82 oC and the new Heat Pump system or Renewable Energy System has a water temperature of 35 oC then your existing radiator surface area may well not be sufficient to warm the room.

HOW TO FIND THE OUTPUT REQUIRED FOR YOUR ROOM

After using the “Easy heat guide for your room” LINK shown at the bottom of each radiator page on the AEL website you now know the heat required for your room so you can now check that the FARAL Aluminium radiators you have chosen will provide enough heat output.

HOW TO CHOOSE THE CORRECT RADIATOR SIZE

Once you know the output required for your room and the model of the radiator you prefer there is a simple calculation to check if the radiator you have chosen will provide sufficient heat output for your room by checking the “Delta T”, please see below:

HOW TO CALCULATE THE DELTA T OF A RADIATOR

The FARAL Aluminium radiator brochure provides a standard heat output figure based on a flow temperature out of the gas boiler of 80 oC which gives an overall delta t of 50 oC.

Calculate Delta Radiator

Using an 80 oC water flow in temperature, and a 60 oC water flow out temperature the average temperature in the centre of the radiator is 70 oC.

If we take away the average room temperature of 20 oC from the 70 oC average temperature across the radiator we are left with a Delta T of 50.

REDUCED WATER TEMPERATURE WHEN USING A HEAT PUMP

The water flow temperature from your Heat Pump to the central heating system is a far lower water temperature than if it was supplied from a gas boiler so you will need to calculate a new output figure by multiplying the output figure shown in the catalogue LINK by a figure shown on the correction chart below.

If the “Delta t” in the catalogue is 50 oC and your system “Delta t” is 50 oC then the correction factor is = 1 on the chart below which means it is perfect so just use the outputs shown in the catalogue.

If the system “Delta t” is more or is less than 50 oC then look at the actual system temperature on the left hand side of the chart and multiply the output shown in the catalogue by the factor shown on the right hand side of the chart, this will give you your new output for the radiator.

CALCULATED DELTA T     CONVERSION FACTOR

5                                      0.050

10                                      0.123

15                                      0.209

20                                      0.304

25                                      0.406

30                                      0.515

35                                      0.629

40                                      0.748

45                                      0.872

50                               1.000  

55                                      1.132

60                                      1.267

65                                      1.406

70                                      1.549

75                                      1.694

Reduced Water Temperature