What Thermal Insulation Means

Thermal insulation of a home involves a set of measures designed to prevent heat exchange between the interior of the building and the outside environment — in short, to stop heat loss.

When analyzing heat loss in a home, studies show that:

• 35% of heat is lost through uninsulated walls

• 15% through unprotected floors

• 25% through unsealed windows and doors

• 25% through uninsulated roofs or ceilings

Thermal insulation is essential for ensuring increased indoor comfort, both in the cold season and during summer. To achieve this, it's important to choose a high-performance insulation material. Heat loss directly impacts gas consumption for central heating and translates into financial loss caused by an inadequately insulated home.

Windows and Doors

Proper thermal insulation of windows and doors requires evaluating the insulation performance of their two main components: the frame and the glazing. The thermal transfer coefficients — Uf (for the frame) and Ug (for the insulating glass unit) — are key indicators. The overall window performance is represented by the Uw coefficient, which is calculated based on both Uf and Ug. The lower the Uw value, the better the window insulates and the less heat is lost.

Ceiling/Roof and Floor

Together, the ceiling and floor can account for up to 40% of total heat loss, yet they are often overlooked when it comes to thermal insulation.

Failing to insulate these areas properly results in high energy consumption just to maintain a comfortable indoor temperature.

For example, let’s consider a home with 100 m² of floor space and a ceiling height of 2.5 m (250 m³ volume). Using the calculation method from a previous article:

• Well-insulated walls, ceiling, and floor; high-efficiency windows and doors:

  250 m³ × 30 kcal × 1.163 W/kcal × 20% (margin of error) = 10,467 W (~10.5 kW)

• Poorly insulated walls, ceiling, and floor; inefficient windows and unsealed doors:

  250 m³ × 70 kcal × 1.163 W/kcal × 20% = 24,423 W (~24.5 kW)

Conclusion

Although thermal insulation represents a significant initial investment, it will pay for itself over time through energy bills reduced by up to 50%, while offering increased thermal comfort during the cold season.