Does radiator foil actually save energy?

It helps most when the radiator sits on an uninsulated external wall, reflecting heat back into the room. Gains are modest and shrink if the wall is already insulated or the foil is poorly fitted.

Cut the roll to the radiator's size, then fix it to the wall behind the radiator with the adhesive backing or double-sided tape. Foil should face the room.

Can I use it on windows or in a campervan?

Yes. The same foil works as a thermal barrier for windows, roofs, conservatories and motorhome walls. It blocks radiant heat rather than adding structural insulation.

Is it fire safe behind a radiator?

The material is foil-faced foam, and no fire rating is stated. Keep it clear of direct contact with hot pipes and check the manufacturer's guidance for use near heat sources.

The foam core is 3 mm thick, so it is flexible and easy to cut but adds little bulk insulation compared with rigid boards.

Radiator Reflective Insulation Film PET Aluminized Foil Roll

Best price now

$10.90at WalmartChecked 1 h ago

Prices are checked against each store and labelled with when.

Visit Walmart

Radiator Reflective Insulation Film PET Aluminized Foil Roll

Best price now

$10.90at WalmartChecked 1 h ago

Prices are checked against each store and labelled with when.

Visit Walmart

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Price facts

Lowest price today: $10.90 at Walmart (checked Nov 14, 2026).

Our take on the Radiator Reflective Insulation Film PET Aluminized Foil Roll

This is a roll of reflective foil insulation with a 3 mm foam backing, meant to be cut to size and placed behind a radiator to bounce heat back into the room instead of into the wall. It also works as a general thermal barrier for containers, motorhomes, conservatories, roofs and sunny windows. It is a low-cost, low-effort upgrade rather than a replacement for proper wall insulation, and it suits renters and DIYers who want a quick fix without drilling or plumbing. Compared with plain foil-only films, the foam layer adds a little bulk and sound damping; compared with rigid foil-faced boards, it is thinner and more flexible but less durable.

Best forRenters who can't modify wallsCold rooms with radiators on external wallsDIY weatherproofing and campervan insulationCheap quick thermal fixes

Pros

Reflective foil plus 3 mm foam backing
Cut-to-size with scissors or a knife
Adhesive backing or double-sided tape fitting
Also usable on containers, roofs and windows
Moisture, corrosion and ageing resistant

Cons

Thin foam gives modest insulation value
Tape fixing is less durable than adhesive
Adhesive can leave residue or fail on rough walls
No stated fire rating
Effect depends heavily on correct fitting

Radiator Reflective Insulation Film PET Aluminized Foil Roll prices at every store

WalmartNew
In stockSold by SparkPulsett
$10.90+ $4.25 shippingChecked 1 h ago
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Radiator Reflective Insulation Film PET Aluminized Foil Roll price history

$11.19$10.90

Nov 4Nov 14

Lowest price we've seen: $10.90 on Nov 14 at Walmart; highest $11.19 on Nov 4. Tracked across 1 store since Nov 4.

About the Radiator Reflective Insulation Film PET Aluminized Foil Roll

This is a roll of reflective insulation film made from PET aluminized film. It is placed behind a standard radiator to help raise the temperature of a room that is not warm enough. It fits any radiator model.

The film is attached with a special adhesive. Double-sided tape can also be used, but it is rarely recommended because of durability. Cut the film to the size of the radiator before installing it.

The material insulates against heat and sound and resists moisture, aging and corrosion. It can also insulate motorhomes, sun-lit windows, conservatories, roofs, car windows and various containers. It can be used for insulated bags to carry food and flowers.

Material: PET aluminized film
Reflective type: Reflective
Sizes: 16.4 ft x 0.98 ft (5 m long); 32.8 ft x 0.98 ft (10 m long); 5 m x 0.5 m (16.4 ft x 1.64 ft); 10 m x 0.5 m (32.8 ft x 1.64 ft)
Properties: Thermal insulation, moisture resistance, sound insulation, low friction, aging resistance, corrosion resistance
Installation: Special adhesive or double-sided tape; cut to size first
In the box: 1 roll of radiator reflective film

Specifications

Reflective Type: Reflective
Size: 0.3 x 5 m
Actual Color: silver
color: silver

Questions and answers

Does radiator foil actually save energy?: It helps most when the radiator sits on an uninsulated external wall, reflecting heat back into the room. Gains are modest and shrink if the wall is already insulated or the foil is poorly fitted.
How do I install it?: Cut the roll to the radiator's size, then fix it to the wall behind the radiator with the adhesive backing or double-sided tape. Foil should face the room.
Can I use it on windows or in a campervan?: Yes. The same foil works as a thermal barrier for windows, roofs, conservatories and motorhome walls. It blocks radiant heat rather than adding structural insulation.
Is it fire safe behind a radiator?: The material is foil-faced foam, and no fire rating is stated. Keep it clear of direct contact with hot pipes and check the manufacturer's guidance for use near heat sources.
How thick is it?: The foam core is 3 mm thick, so it is flexible and easy to cut but adds little bulk insulation compared with rigid boards.
Where is the Radiator Reflective Insulation Film PET Aluminized Foil Roll cheapest?: At Walmart, for $10.90, as of our latest check.