Houses represent more than a third of the planet’s energy consumption, and it is increasingly common to hear about efficent energy. But what does “efficient energy” mean and what does it do? Well, let's start at the beginning: when talking about energy efficiency in any field, “the goal is to reduce the amount of energy required to provide services." If the consumption statistics were observed in a building, we would see that more than half of the total energy used is required for cooling or heating the interior spaces. So, before we start talking about energy, it is essential that we understand the relationship that exists between our interior spaces and the exterior temperature. That difference in temperature is where we need to improve the energy efficiency of our homes. In this instance, the enclosures (walls, windows, and ceilings) become protagonists. The thermal transfer of the materials (that is, the amount of heat they allow to enter or leave the home), must be dimensioned in such a way that the least amount of energy is needed to achieve interior comfort. This investment will cause a decrease in consumption, which means less natural resources will be consumed (even if they are from renewable resources), and the cost of energy bills will be reduced.
The insulation used depends on the place where the building is located. In some very warm places, it is advisable to prioritize natural ventilation before completely insulating the house, but in very cold and temperate areas, insulation is the best option. In addition, the color of the enclosures (dark colors absorb heat, making them very counterproductive in warm places), and the coatings of the enclosures (there are paintings and mortars that repel heat) must be taken into account. It is important to contact a professional so that they can advise on what to use for your project.
Types of Insulation
As we mentioned earlier, the insulation is placed on the architectural elements that protect our interior from the outside: walls, roofs and windows. In the case of soils, it is not usually necessary to add insulation, unless, for example, you want to isolate the ground floor of a very cold subsoil. Depending on the element, the options that exist in the market will vary, and which one is the best option will depend on the individual situation.
The best type of insulation will depend on the construction system with which the project is being or has been built. There are systems such as steel or wood frames that already have insulation inside. However, in brick constructions, decisions will need to be made on how incorporate it. Here are some of the most popular alternatives according to where it is placed in relation to the wall:
1.External Thermal Insulation Composite (ETIS)
This alternative proposes placing the insulation on the outer face of the wall. This works well because it prevents heat from entering the wall. It also helps prevent thermal bridges (spaces where heat is filtered by poorly insulated elements: for example, beams). In addition, if it is used while renovating the building, the inhabitants of the building can continue their life without since the work is outside. The final result can be painted or covered with a coating. The drawbacks of this system are that it increases the surface area of the building (which is why it must be approved by city regulations) and that it cannot be used on protected facades.
2. Insulation placed inside
This system of insulation is placed on the inside face of the wall and then covered with single or double plasterboard, depending on the strength required. It is easy to install and can be done in stages (for example, in the rooms that are considered most necessary or without wanting the entire neighborhood to weigh in), and, most importantly, on buildings with protected facades. However, it does not prevent the presence of thermal bridges and it diminishes the surface area of the rooms, so special considerations must be taken in spaces that already have the minimum required measurements.
3. Insulation in air chambers
This system consists of projecting polyurethane foam inside the air chambers. In the case of new constructions, it is not usually the best alternative, since the quality of the placement cannot be exactly guaranteed. However, in cases of renovations that have enclosures with an air chamber, it is a good option since it is a simple, quick intervention that significantly improves thermal regulation.
The correct insulation on roofs is very important since it is the surface that receives constant radiation from the sun. The available systems are usually very similar to those used in walls and can be placed on flat, traversable and gabled roofs. In the latter case, the insulation may be placed immediately under the tiles or sheet metal; in a renovation, it can be placed on the false ceiling, thus simplifying the work (although it is recommended that the roof be ventilated).
In the cases of green roofs, the earth and the plants will collaborate with the insulation (which does not mean that is not necessary to install more insulation). However, it is important to be aware of the desired thickness of the green roof, since it can start working by thermal mass (absorbing heat during the day and releasing it during the night) and be counterproductive.
Windows are the most sensitive construction element to consider when insulating a building. The crystals, being transparent and fine materials, never meet the requirements of the thermal process in the same way a wall does. However, there has been a lot of progress in their designs, and there are now triple-glazed and solar-controlled glass options. The most advisable thing is, in addition to making an appropriate choice for the building, to combine the design with shade elements such as blinds or awnings, depending on the window orientation.
Another difficult element is the gaps that are usually found in the frames of the windows. The most commonly used materials for window frames are:
- Polyvinyl Chloride (PVC):
this material behaves very well thermally, but it is not recommended because of its low recyclability and dangerous toxicity in cases of fire.
the thermal transfer with aluminum is less efficient than that of PVC, but its recyclability is very high. However, it often creates problems in its adhesion with the wall since it causes thermal bridges, which can cause condensation inside the house during the cold months. When choosing a window frame, it is important to ensure that it has a thermal bridge break.
this is the most ecological material and works well thermally but requires maintenance over time.
Now you know the importance of insulating a building for optimal energy efficiency and some of the insulation options. Which one are you going to use for your project?