The heat losses are all heat losses that can occur in your home. In question? The poor insulation in your home. To save energy, hunting down thermal losses must be your first priority! For this, we explain how to find the causes and how to remedy them.
Where does the heat loss come from?
It is important to know the weak points of your home. This allows you to know what types of work to turn to optimize its thermal quality. You should know that there are many sources of heat loss in a house. Among these sources, the most important are: the roof, walls, air renewal, glazing, low floor, and thermal bridges.
The roof: 30% waste heat
In terms of heat loss, the roof represents the first weak point of a home. It is the source of nearly 30% of thermal losses for several reasons:
- its large contact surface between the interior and the exterior
- its exposure to the wind
- the fact that the heat created in the home tends to rise more
The roofs are sources of heat loss on several levels: lack of insulation of the last ceiling, lack of insulation of the attic and sub-slopes, air leaks between the tiles. This is why roof insulation is undoubtedly the most recommended energy renovation operation by professionals.
The walls: 20% waste heat
The walls are on the second step of the podium and closely follow the roof in heat loss. In general, in France, the walls are rather poorly insulated, with only fine insulation on the inside. To be effective, it is however necessary to have a strong thickness of insulation, and rather outside your home.
Air leaks and air renewal: 20% heat loss
Air leaks can be numerous in a house and often poorly handled by craftsmen and builders. They can come from chimneys, hoods, locks, electrical ducts, or even door frames. To give you a concrete example, they alone represent the equivalent of a window remaining wide open all day! It is therefore important to be concerned about it.
Glazing: around 15% waste heat
Finally, glazing only comes in the fourth position in this classification of sources of heat loss in a home. This is explained by the existence in France of good material concerning the openings. Today, windows meet demanding manufacturing criteria, with well-controlled processes. It, therefore, inherits a good performance in terms of insulation.
The low floor: around 10% waste heat
This cause of heat loss mainly concerns old houses. The low floor is better and better treated and therefore more efficient! If the losses are certainly low, they still participate in a feeling of discomfort and a feeling of cold at home. By reflex, you surely tend to increase the heating to avoid these inconveniences. This is unfortunate enough to increase your energy consumption!
Thermal bridges: around 5% of waste heat
The thermal bridge designates a zone that is in direct contact with the outside, without any insulation coming to the buffer. This is for example the floor of the second floor, which rests on the exterior walls. Less dangerous than the others, they still represent a small loss of heat. On the other hand, it is quite complicated to fight!
Measure the level of heat loss
There are easy ways to calculate heat loss in your home. The two most important are the thermal balance and the thermal camera.
- The thermal balance method: consists of calculating the thermal balance of a particular room or of your home as a whole. This calculation includes the volume to be heated in m3, the difference between the indoor and outdoor temperature, and the coefficient G. The coefficient G measures the heating power required for a particular volume. You get a number between 0.4 and 1.5: the higher this number, the more poorly insulated the home!
- The thermal camera method: consists of using a the program. It is an image that displays the heat losses, thermal bridges, and insulation defects of the dwelling using colors.
How to remedy thermal losses?
Once you know the weak points of your home, you can take action on them! For each problem, there is a solution.
Insulate your roof
The first action is to insulate your roof, the main cause of heat loss. For this, several solutions exist:
- If you have lost attics, nothing could be simpler! You just need to do insulation by blowing flakes on the floor. It is a quick and inexpensive technique. In one day, heat loss through the roof is a distant memory.
- Conversely, for convertible attics, you must insulate your roof. You have the choice between insulation from the inside with insulating panels under the roof, or from the outside by installing insulation under your tiles or slates.
Insulate your walls
For walls, it’s no secret, the best method is thermal insulation from the outside. It is the most efficient solution since it even eliminates thermal bridges in your home. So you save even more energy.
Insulate your openings
For windows, shutters, and doors, it is recommended to choose double or even triple glazing. For more thermal efficiency, we also advise you to choose materials with high insulating qualities such as wood, aluminum, and PVC. There are also specific insulators such as window seals, expanding foam, or even cold and heat-insulating curtains. A high energy performance front door allows you to reduce your energy consumption. Better thermal insulation also allows you to benefit from better acoustic comfort and enhance your home.
Insulate your floor
Floor insulation is done either from above or from below. But each of the techniques has advantages and disadvantages. Insulation from above: the insulation is installed on the low floor. This technique adds a little thickness to your floor and requires you to adapt your doors. In renovation, this is not the easiest method to implement!
Insulation from below: here, the insulation attaches to the ceiling of the space below your floor. It can be a crawl space, a basement, or a cellar. You just need to have enough space for your craftsman to do his job. Usually, one meter in height is sufficient.
Reduce thermal bridges
For this problem, the ideal is to insulate your entire house from the outside. Another possibility is to reinforce the floors with aerated concrete and floating slabs.