Disadvantages of foil behind Radiators

Last updated: November 23, 2023

Does placing foil behind your radiators actually help slow down heat loss and save money on your heating bills?

As the name implies radiators themselves are designed to radiate heat into their surroundings e.g. into your living space.

The logic behind radiator reflectors is that they help the heat radiated from your radiator be reflected back into your living space as opposed to being lost in the wall behind the radiator.

Disadvantages of Foil Behind Radiators

Why should you use tin foil or aluminium foil behind your radiators?

The main reason you should not use traditional kitchen foil behind your radiators is simply that it isn’t designed for this purpose.

These are the major reasons why aluminium foil is a bad idea (as opposed to purpose built radiator reflectors):

  • Foil will crinkle and is unlikely to stay in the same position for long.
  • Over time foil will degrade and oxidise, diminishing its ability to reflect heat.

Why use radiator reflectors instead?

The alternative to placing foil behind your radiators is a radiator reflector like those offered by the brand Radflek – easily found on Amazon.

Unlike tin foil, these will not be at the mercy of oxidisation and will maintain their shape and integrity over time.

Radiator Reflectors Real Term Savings

How much energy and money can you save by installing radiator reflectors?

Research was carried out by the BRE and shows that substantial savings can be made by installing Radflek radiator reflectors.

Type of PropertySavings per radiator / yr (0.6sqm)Payback (Years)
Insulated Cavity Walls£0.803.7
Post 1983 Cavity Walls£1.322.3
1976-82 Cavity Walls£1.911.6
Pre 1976 Cavity Walls£2.751.1
Uninsulated Solid Walls£4.020.7

The British Board of Agrément (BBA) and verified by the BRE, also highlight that Radflek products can reduce heat transfer through walls by 45%.