Thermal inertia and its effects on energy consumption

Old houses often have thick stone walls, giving them significant thermal inertia. This characteristic greatly influences the energy consumption needed to heat the dwelling. Understanding thermal inertia and its impact on the choice and adjustment of the heating system is crucial.

Radiators: how to choose and adjust?

• Type of radiators: The choice of radiator type ultimately has little impact on the overall performance of the heating system. Cast iron radiators, for example, are quickly subjected to very high temperatures. They offer little exchange surface, which limits the efficiency of heat transfer to the water.
• Water regulation: Regulating the temperature of the water circulating in the radiators is a key element to monitor. By adjusting the water temperature to the specific needs of each room, one optimizes heat diffusion while limiting energy losses.

Thermal insulation: essential for improving comfort

In a building with high thermal inertia, insulation remains paramount to limit energy losses. By adding quality insulation, one reduces the effort of the heating system and can thus operate with lower parameters.

External insulation: a way to improve indoor comfort

It is highly recommended to prioritize external insulation, which will help maintain thermal inertia while ensuring uniform heat distribution indoors. This method has the advantage of not encroaching on livable space.

Precise regulation: key to controlling energy consumption

To optimize energy consumption, it is essential to accurately control the temperature in each room of the house. A good radiator adjustment, combined with effective control of the water temperature, will help avoid unnecessary overheating and achieve significant savings.

Don’t be misled by short-term readings

Temporary fluctuations in outside temperature or the amount of hot water used can temporarily impact the heating system’s performance. Therefore, one should not rely on very short-term measurements to judge the efficiency of their installation.

The choice of an insert: a false good idea?

Fireplace inserts with blown air may seem like an appealing supplementary heating solution, especially in buildings with high thermal inertia. However, they have several disadvantages:

• They generally have a poor efficiency, around 50%. As a result, half of the generated heat is lost.
• Inserts often produce heat that is poorly distributed and uncomfortable, as it primarily concentrates near the fireplace.

To optimize the comfort and energy consumption of an old house with high thermal inertia, it is important to closely monitor the regulation of the radiators and the temperature of the water used for heating. Adding effective insulation, particularly from the outside, will further reduce the energy needs for heating while preserving thermal inertia. Do not be tempted by supplementary solutions such as inserts, which are often underperforming and can create more discomfort than real benefits.