Skip to content

Insulate wall behind radiator – Install reflective thermal insulation panels and save heating energy.

If you want to reduce your heating costs in winter, you can insulate your radiators by installing insulation panels behind them as thermal protection. After all, poor heating performance can result from heat loss that takes place in the radiator niches. Instead, good insulation in terms of heat output could be a smart way to increase energy efficiency. Below are some tips and important information about thermal insulation in radiator niches in different ways.

How an insulation board alu laminated can insulate radiators

insulate wall behind radiator and save heating energy in winter season

This system is the simplest of all and can be implemented even by less experienced people. In fact, heat-reflective insulation panels in major home improvement stores are not expensive and provide a cost-effective option for interior thermal insulation. In addition, there are different thicknesses, although it is advisable to focus on 3 to 6 millimeters. Thus, you can achieve optimal thermal protection . After purchase, you need to cut the panel and use it to insulate radiator niche. As an advantage, you prevent heat loss, thereby insulating walls behind radiators. All the existing heat thus reflects in the room and stays there much longer.

advantageously optimize energy efficiency and insulate radiators with insulation board

Thus, the installation of an insulating panel with reflective film does not require any prior knowledge. In this case, the structure plays the role of a barrier between the heat source and the outer wall surface. As a result, the room temperature can increase by 2-3 degrees, and at the same time you reduce your energy consumption by 5-7%. Since heaters in buildings are usually located under windows, the main goal is to warm up the air inside and create a heat curtain that prevents the penetration of cold from the street. In addition, this spreads heat from a heated object to a cold one. The wall temperature is correspondingly lower than that of the radiator. In the cold season, the surface behind it heats up to 35-40 °C. Thus, you can spend part of the energy for heating the outer walls.

Advantages of thermal insulation in radiator niches

save heating energy in winter by installing thermal insulation on the wall

Thus, when you insulate behind radiators with such an element, you redirect heat to the interior of the room instead of heating the outer walls. This allows you to increase the temperature in the living space and save on heating costs at the same time. Such installations can also be decorative, emphasizing inconspicuous places. Due to the cold air from below, the radiators also do not clog with dust and are easy to clean. However, the main advantage remains the supply of warm air into the room and the prevention of moisture penetration.

Use expanded polyurethane foam

insulate wall behind radiator with reflective foil and improve heat


Fabrics have a different ability to conduct heat. To reduce energy consumption, the reflective screen must have a low thermal conductivity – not higher than 0.05 W / (m ∗ K). However, indoors it is not recommended to use structures made of combustible materials with loose structure. For example, mineral wool, which emits formaldehyde and microscopic dust, is not suitable for thermal insulation indoors. A suitable coefficient of thermal conductivity is 0, 039 W / (m ∗ K).

thermal conduction and energy efficiency behind a radiator insulate with thermal insulation board

However, the best proven reflective panels made of insulation materials based on polyurethane foam. They are hypoallergenic and safe for human health. The thermal conductivity of different types ranges from 0.029 to 0.032 W / (m ∗ K). Four millimeters of this barrier hold the same amount of heat as 10 centimeters of mineral wool. So, for insulation between the wall and the heater, a layer of 3 to 5 millimeters is enough. In this case, you should duplicate the heat-insulating screen behind the radiator with aluminum.

Apply the method with foam

This method requires more experience in the industry. In fact, the installation consists of a small work on the wall, limiting the perimeter of the radiator niche, to perform thermal insulation directly behind the radiators. You can proceed as follows:

  • Drill a few symmetrical holes in the wall with a drill.
  • Inject polyurethane foam, which by nature dries instantly and expands in the holes to create optimal insulation.
  • Of course, you will then need to retouch the wall for aesthetic improvement.

Apply reflective film and insulate radiators.

insulate radiators and save heat by placing aluminum foil on the wall


Nowadays, many companies and firms produce reflectors for radiators, which are designed to reflect different energies, in this case heat. These improve the efficiency of heating devices such as radiators, convectors and many others. The metallized side comes into contact with the heating coil during installation and reflects the heat energy towards the room, which increases the efficiency of heating. Polished aluminum has a higher reflectivity for thermal radiation than other metals. This means that the maximum heat returns to the room. However, it is not worth using insulation panels with a double-sided metal back. The foil layer on the side of the cold wall does not carry any functional load – it simply has nothing to reflect.

Disadvantages of thermal insulation panels in radiator niches

turn up the heat in the cold season and feel warm at home by insulating radiators

The area behind the radiator is not more than 5% of the total area of the outer wall of the room. The main heat loss occurs through infiltration and windows. Against this background, the improvement of heat transfer in the range of half a meter is tiny. However, when you add up the reduction in heat loss throughout the building, the savings are significant. Therefore, in the case of uninsulated walls with low thermal resistance, a reflective thermal insulation panel is rather useless. In such cases, the heat loss is so great that the improvement in heat transfer is not even noticeable on a plot of 0.5 m².

insulate radiators and improve thermal conductivity in the room with alu-laminated insulation board

In buildings where heaters are located in niches, the heat loss is higher. The walls behind the radiators are thinner and colder than the others. In addition, the heat is emitted not to one, but to three low-temperature surfaces at the same time. Therefore, if space allows, it is worth increasing the thickness of the insulation to 10-15 millimeters. In addition to the material, it is important how the reflective screen can insulate heat from the radiator by fixing it. Accordingly, poor installation negates the whole expected effect.

Avoid mistakes and insulate radiators through proper installation.

installation of a radiator on the wall with precise measurements and prior knowledge avoid errors

If the distance between the floor and the lower part of the radiator is less than 10 centimeters, the productivity of heat transfer decreases and cleaning becomes more difficult. Therefore, do not raise the radiator too high. If the distance between the floor and the heater is more than 15 centimeters, the air temperature gradient increases relative to the height of the room, especially in the lower part. So do not install your heater near another wall. In addition, the distance between the top of the heater and the window sill should be at least 15 centimeters. Less will worsen the heat flow. It makes the most sense to provide for the installation of a reflective insulation board already during the construction phase and after the shell, before the installation of the heater.

professional installer installs a black insulating radiator on the wall

  • When the repair is completed and the radiator is in place, you need to remove it.
  • The size of the thermal insulation panel must match the working surface of the heater. Then this will be almost invisible and will not spoil the appearance of the interior.
  • If there is enough space, a grid base of thin wooden boards is also a more reliable option. In addition, this creates a layer of air between the wall and the thermal insulation board, which has a positive effect on heat transfer.
  • It is important to adjust the position of the radiator so that between the foil cover and the back there is a gap of at least one and a half centimeters.
  • As a rule, a thermal insulation panel does not require special care. Sometimes it is enough to wipe the dust on it.
  • If the aluminum layer is scratched or torn, metallized tape helps to remove the damage, which in no way affects the functionality.