Comparative of thermal insulators: which material offers the best performance at equal thickness?

Choosing thermal insulation is not just about opting for a familiar name, but requires careful consideration of the true performance of materials. Thermal conductivity, this fundamental characteristic, conditions the efficiency of insulation. The importance of optimal insulation is expressed through pressing economic and environmental issues. Only a rigorous evaluation of the thermal resistances of each material will reveal the perfect alliance between efficiency and thickness. The goal is to select the best insulation, capable of significantly reducing heat losses while preserving natural resources.

Thermal performance of insulations

The performance of thermal insulations is mainly evaluated by two criteria: thermal conductivity (λ) and thermal resistance (R). Thermal conductivity expresses the material’s ability to transmit heat, measured in W/m·K. Insulations with a low λ ensure better insulation. As for thermal resistance, it is calculated by the ratio of the material’s thickness to its conductivity. The higher the R value, the better the material will perform as insulation.

Synthetic insulations

Synthetic insulations, such as polyurethane and expanded polystyrene (EPS), often attract attention. Polyurethane, with a λ ranging from 0.022 to 0.028 W/m·K, excels with its thermal efficiency. It is available in rigid or spray foam, providing optimal performance even at low thickness. On its part, expanded polystyrene, often used in board form, shows a λ between 0.030 and 0.038 W/m·K. Although it falls short compared to polyurethane, it remains very popular for its quality-price ratio.

Mineral insulations

Mineral insulations such as glass wool and rock wool have distinct characteristics. Glass wool, with a λ ranging from 0.030 to 0.040 W/m·K, ranks among the most commonly used materials, particularly in attic insulation. It also offers good acoustic qualities. In contrast, rock wool, with a λ close to 0.033 to 0.044 W/m·K, excels in fire resistance, thus providing additional safety.

Natural insulations

Natural insulation materials, such as cellulose wadding and hemp wool, are experiencing a resurgence of interest. Cellulose wadding, made from recycled paper, shows a λ ranging from 0.039 to 0.045 W/m·K. This eco-friendly material is distinguished by its ability to regulate humidity. Hemp wool, on the other hand, has a slightly higher thermal conductivity, between 0.040 and 0.050 W/m·K, but offers a significantly lower environmental footprint. These natural insulations are increasingly appealing to environmentally conscious users.

Choosing an insulation for construction

The choice of thermal insulation involves an analysis of performance, costs, and environmental impact. Synthetic materials, while effective, are often criticized for their ecological impact. In contrast, natural insulations, while slightly less thermally efficient, offer undeniable benefits in terms of sustainability. The right material will depend on individual priorities, whether it be costs, efficiency, or environmental respect.

Frequently Asked Questions about Comparing Thermal Insulations

Which insulating material has the best thermal performance at equal thickness?
Polyurethane is often considered the best insulation at equal thickness, thanks to its low thermal conductivity coefficient, which ranges between 0.022 and 0.028 W/m.K.
How to compare thermal insulations based on their thickness?
To compare insulations at equal thickness, it is preferable to refer to their thermal conductivity value (λ); the lower this value, the better the insulation.
What are natural insulations and their performance at equal thickness?
Natural insulations like cellulose wadding and hemp wool have interesting performances, but generally less favorable than synthetic insulations such as polyurethane, with λ values ranging from 0.039 to 0.050 W/m.K.
Is expanded polystyrene (EPS) a good option at equal thickness?
Yes, expanded polystyrene offers a good quality-price ratio with a λ coefficient ranging from 0.030 to 0.038 W/m.K, although it is slightly less efficient than polyurethane.
Why is it important to consider thermal resistance (R) when choosing insulation?
Thermal resistance (R) determines an insulation’s effectiveness in slowing heat transfer. A high R value indicates better performance, which is crucial for reducing energy losses.
Can mineral insulations like glass wool be used at equal thickness with other materials?
Yes, glass wool is commonly used, although it generally has a λ between 0.030 and 0.040 W/m.K, making it less efficient compared to other synthetic insulations at equal thickness.
What is the best method for choosing insulation based on its use?
It is essential to consider thermal conductivity, fire resistance, and acoustic properties depending on the location in the construction (walls, attics, floors). This ensures the optimal choice based on specific needs.
Are low-thickness insulations effective?
Yes, some insulations, like thin reflective materials, can be very effective; however, they must be selected carefully to ensure their performance at reduced thickness.
How important is the ecological impact in the choice of insulations?
The ecological impact is becoming increasingly important in the choice of insulations. Favoring natural materials without petroleum derivatives, such as cellulose wadding or hemp wool, helps to reduce the carbon footprint of construction.