Mur Trombe, how to air-condition a house using only the sun

Trombe Wall

Environmental sustainability and, also, of the national economy, are two strong arguments for containing energy consumption. And the expenses for the heating and air conditioning of the house have a lot to do with it. Indeed, it is estimated that keep the house warm, accounts for at least half of the electricity bill.

In this context, it is not surprising that alternative approaches to construction are gaining prominence, as is the case with the Trombe wall.

This means nothing to you ? This is not uncommon, since this passive air conditioning system dates from the second half of the 19th century.

However, its validity is evident in its effectiveness and ease of application.

For this reason, we detail the advantages of this mechanism, how it works and what it takes to air-condition a house using only sunlight.


What is the Trombe wall and how does it work?

As we mentioned earlier, this is a system designed and patented by Edward Morse in 1881.

However, the idea went unnoticed for decades until, around the 1960s, it began to be applied in passive solar house construction projects.

What is the Trombe wall and how does it work?

In this sense, what this mechanism allows the interior of a house to maintain a stable temperature, summer and winter, thanks to natural light. By refining a little more, the air conditioning is carried out with solar heat contributions.

For this to happen, several components are required which, in any case, are easy to integrate into any single-family home, without the need to be an expert in the field.

How is a trombe wall constructed?

To activate this passive air conditioning system, at least four essential elements:

  1. The wall, of course, but not just any wall. It must have the right orientation to be exposed to the sun for as many hours as possible. In addition, it must be opaque and, last requirement, it must be constructed of high thermal mass materials, such as adobe, concrete or even water. In general, these walls tend to be between twenty and forty centimeters thick.
  2. A translucent glass placed parallel to the wall. If you want to maximize system efficiency, the most recommended would be a low-e glass to reduce heat loss. With this component, we obtain a kind of greenhouse effect crucial for the operation of the mechanism.
  3. Room between wall and glass. Although not an element in itself, it is certainly a key aspect. Thus, between the wall and the glass, a free space of between two and 15 centimeters should be left. In this band, the heat generated by the light passing through the glass and which is absorbed and accumulated on the wall will be maintained. In addition, the glazed outer layer prevents, or at least minimizes, radiation leakage.
  4. Vents. This last part is also fundamental since, without it, how to conduct the hot air from the outside to the inside, or vice versa? This type of grilles at the top and bottom of the wall will take care of precisely this, in addition to helping the inhabitants of the house to prevent drafts that cool it at night or those that cause excessive heating.

Advantages of the Trombe wall.

This simple mechanism, which in its essence works on the same principles as a greenhouse, offers the main advantage of air conditioning a house without the need for heating or air conditioning systems.

Advantages of the Trombe wall.

This, of course, provided the Trombe wall is properly configured to optimize heat transfer from the outside during the winter, in which it would also prevent interior temperature loss.

In summer, on the other hand, a facade well designed according to these principles would attenuate any excess heat.

For example, it is estimated that a wall of about 40 cm would retain heat for at least eight hours before reaching the interior of the house, which would provide respite during the central hours of a summer day and acclimatize the house after dark.

Advantages of the Trombe wall

In addition to all of the above, this durable air conditioning option has, among its strengths, the simplicity of conditioning this mechanism, as well as the minimum effort it requires once activated.

At this point, anyone who opts for this model improve the energy efficiency of your homeyou will only be able to acclimatize it by means of the light which comes from the sun.

Disadvantages of a Trombe wall.

Trombe walls also have their drawbacks.

For example, spaces that are not well insulated to prevent heat loss may never reap the true benefits of solar radiation. However, keep in mind that these spaces will be inefficient regardless of the heat source.

Trombe walls are not very attractive. Inside the house they may look like a typical brick accent wall, but outside the house they may be unattractive. It’s possible to dress them up a bit, but they’ll probably never look as attractive as a standard glass wall.

Moreover, it must be taken into account that a Trombe wall will likely block the main source of natural light in most homeswhich could be a hindrance for some designers and owners.

Ultimately, Trombe walls don’t work everywhere. If the path of the sun is blocked by trees, mountains or other buildings, there is unlikely to be any benefit. Also, in houses that do not have a wall facing directly towards the sun, the Trombe wall will be less effective at the start or end of the day (depending on the situation).


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