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A passive house combines low energy consumption and thermal insulation, offering increased comfort in both summer and winter. Such a house consumes up to 90% less energy for heating compared to an existing house, and 75% less energy than a new building, which must comply with a number of rules regarding energy efficiency.
The idea of a passive house was developed by engineer Bo Adamson and physicist Wolfgang Feist around 1988. Subsequent experiments led to the creation of performance principles for such houses. The term "passive" came from the fact that the heat demand of the house is provided by passive sources, such as energy released by occupants, technical equipment and solar radiation.
● How a passive house works
● Basic principles of a passive house
● Criteria to be met for passive houses
● How to build a passive house
● Differences between a passive house and an eco-friendly house, a green house or a low-energy house
● Certification of a passive house
How a passive house works
Passive house means a thick thermal insulation, about 20-30 centimeters, which significantly reduces heat loss.
Unlike classically designed houses, in the case of the passive house, ventilation is no longer achieved through an uncontrolled ventilation system, through windows, but through a complex installation, adapted to the needs of the house, which aims to recover heat and efficiency. at least 75%.
The system consists of recovering heat and transferring heat energy from the used air to the fresh air introduced into the home. The innovative ventilation system ensures fresh air, free of allergens or dust, throughout the day.
Moreover, passive houses are also designed to provide comfort. This way, you can stay close to the window without feeling cold, regardless of the outside temperature.
However, not all well-insulated houses are considered passive houses. In the certification of such a house are taken into account the thermal insulation, the types of thermal bridges used (windows, plinth, etc.), the positioning of the building in relation to the cardinal points, the degree of tightness, ventilation system, shading (building as a whole, walls, shoulder pads).
Such aspects will help, from the design phase, to know what the energy required for heating will be, what kind of construction elements are more suitable, as well as what costs such a construction involves.
Basic principles of a passive house
In designing a passive house, the five basic principles must be observed. These are:
● Thermal insulation - according to experts, the insulation of the walls needs to be at least 25-30 centimeters, but this also depends on the characteristics of the chosen construction materials. As a general rule, thicker insulating material is better. For exterior walls, the use of mineral or basalt wool is recommended, and this should cover the foundation, walls and roof. In general, for the roof, an even thicker insulation of about 40 centimeters is indicated, in order to limit the heat loss through the most problematic area from this point of view. It is important to study carefully the characteristics of the windows, because you will do yourself a disservice, if you insulate the house correctly, but you let the heat be lost through the standard windows. In this sense, the use of triple-glazed glass windows (a double-glazed window is about 24 mm thick, while a triple-glazed window is about 40-55 mm). At the same time, their installation requires extra attention, as there may be gaps between the wall and the window frame, which leads to heat loss;
● Elimination of thermal bridges - consists in the efficient insulation of the doors, the use of special materials at the contact of the foundation with the ground, at the connection between the walls, at the floors and in the roof area;
● Sealing the air circulation - the goal is to keep warm air from getting lost inside. A special fan is installed to help prevent heat loss. In general, a passive house is 4-5 times more airtight than an ordinary one;
● Heat recovery air ventilation (sometimes called "double air ventilation") - tightness is one of the basic characteristics of a passive house. As there is a permanent need for fresh air, use HRV (heat recovery ventilation). Such a system allows air to circulate and at the same time heats / cools it (as needed), using 95% heat or coolness (taken from the toilet, closet, etc.) inside. If necessary, such a system can also be used to heat water. For a house of about 120 square meters, the system costs between 800 and 1500 euros;
● Correct positioning relative to the cardinal points - this requirement can be omitted by many people, but can help reduce heat costs. The roof of the house must be arranged in such a way as to allow the sun's rays to penetrate in winter and to provide shade in summer. The thermal house should be oriented correctly towards the sun. Solar energy is captured, in the case of passive houses, by the window system of the house. Depending on the orientation of the building, it captures 40-60% of the light, if the orientation is south, 10-15% of energy, if it is north, and just under 20%, if it is east or west. The solar energy that reaches through the windows is stored by special materials with an increased inertia. The heat accumulates in the house, and through the ventilation system, the temperature rises evenly throughout the house, but without heating. However, if you choose a south-facing direction, it is advisable to use plants or blinds during hot weather to reduce the amount of heat absorbed by the sun.
Another important aspect that you can take into account is the choice of friendly appliances with low energy consumption. For example, the most energy-efficient refrigerators consume less than 200 kWh per year. An ordinary refrigerator, on the other hand, can consume between 350 and 1,400 kWh per year.
Criteria to be met for passive houses
Passive houses are an international standard in low-energy buildings. Below are the main criteria that must be met by passive houses:
● Specific energy requirements for heating or cooling: <15 kWh / m2 per year;
● Maximum required: <10 W / m2;
● Specific primary energy requirements: <120 kWh / m2 per year;
● Leakage: n50 <0.6 h-1. This number refers to how much the volume of air in the building has changed in one hour;
● Conventional energy use: <120 KWh / m2 per year. If renewable energy is also used, the conventional energy will be: <60 kWh / m2 per year;
● During the summer months, excessive temperatures occur at most 10% of the time.
How to build a passive house
The construction of a passive house starts from the project stage. Its preparation must take into account the criteria imposed by the PH (Passivhaus) standard.
In other words, no matter what the house looks like, where the kitchen or pantry will be located, the builders must follow a number of principles. In addition, the energy balance must be carried out in a special software program for the design of passive houses, PHPP (Passivhaus Projektierungs Paket).
Unlike an ordinary house, in the case of passive housing, a specialized design team is needed for this type of project.
If properly designed and built, the installation, architecture and structure will be harmoniously combined. In general, the design time is longer. Each element will be checked for temperature variations, areas where condensation may occur will be identified and resolved.
Differences between a passive house and an eco-friendly house, a green house or a low-energy house
The passive house must meet a number of stringent requirements in terms of energy consumption for heating / cooling, the need for primary energy and the degree of tightness. Eco-friendly houses, green houses or low-energy houses, however, are somewhat more vague concepts and are not internationally certified.
The house with low energy consumption, popularly called ZEB (net zero energy building), aims to consume less energy than produced. The first house of this kind used solar energy to heat and cool the house, introduced concepts such as over-insulation and sealing. Reducing energy consumption, as close to zero as possible, is achieved by using energy resources from renewable sources, especially solar energy.
The ecological house resides both in a low energy consumption and in a clear objective: a minimal impact on the environment during its construction, use and decommissioning. During construction, natural, renewable, recyclable materials, possibly purchased locally, are mainly used to reduce the effects of transport on the environment.
The passive house can also be ecological, but for this, it is necessary to use environmentally friendly materials at the time of construction. It is estimated that the incorporation of the ecological aspect in passive houses will lead to an increase in costs of up to 300 euros per square meter.
Certification of a passive house
Passive houses are certified by the Passivhaus Institute in Darmstadt (Germany) and other globally accredited building certifiers.
The passive house standard is offered to individual homes as well as office buildings, schools, kindergartens, hospitals, supermarkets or indoor swimming pools.
In a world where resources are limited, the passive house can be a solution to enjoy comfort and at the same time reduce environmental pollution. The design of such a house is complex and requires familiar help with this concept. It is important to be aware of every step of the construction in the design phase, with the choice of materials, but also in terms of the actual construction of the house. A passive house means a concern for the environment, but also for the future.
The idea of a passive house was developed by engineer Bo Adamson and physicist Wolfgang Feist around 1988. Subsequent experiments led to the creation of performance principles for such houses. The term "passive" came from the fact that the heat demand of the house is provided by passive sources, such as energy released by occupants, technical equipment and solar radiation.
● How a passive house works
● Basic principles of a passive house
● Criteria to be met for passive houses
● How to build a passive house
● Differences between a passive house and an eco-friendly house, a green house or a low-energy house
● Certification of a passive house
How a passive house works
Passive house means a thick thermal insulation, about 20-30 centimeters, which significantly reduces heat loss.
Unlike classically designed houses, in the case of the passive house, ventilation is no longer achieved through an uncontrolled ventilation system, through windows, but through a complex installation, adapted to the needs of the house, which aims to recover heat and efficiency. at least 75%.
The system consists of recovering heat and transferring heat energy from the used air to the fresh air introduced into the home. The innovative ventilation system ensures fresh air, free of allergens or dust, throughout the day.
Moreover, passive houses are also designed to provide comfort. This way, you can stay close to the window without feeling cold, regardless of the outside temperature.
However, not all well-insulated houses are considered passive houses. In the certification of such a house are taken into account the thermal insulation, the types of thermal bridges used (windows, plinth, etc.), the positioning of the building in relation to the cardinal points, the degree of tightness, ventilation system, shading (building as a whole, walls, shoulder pads).
Such aspects will help, from the design phase, to know what the energy required for heating will be, what kind of construction elements are more suitable, as well as what costs such a construction involves.
Basic principles of a passive house
In designing a passive house, the five basic principles must be observed. These are:
● Thermal insulation - according to experts, the insulation of the walls needs to be at least 25-30 centimeters, but this also depends on the characteristics of the chosen construction materials. As a general rule, thicker insulating material is better. For exterior walls, the use of mineral or basalt wool is recommended, and this should cover the foundation, walls and roof. In general, for the roof, an even thicker insulation of about 40 centimeters is indicated, in order to limit the heat loss through the most problematic area from this point of view. It is important to study carefully the characteristics of the windows, because you will do yourself a disservice, if you insulate the house correctly, but you let the heat be lost through the standard windows. In this sense, the use of triple-glazed glass windows (a double-glazed window is about 24 mm thick, while a triple-glazed window is about 40-55 mm). At the same time, their installation requires extra attention, as there may be gaps between the wall and the window frame, which leads to heat loss;
● Elimination of thermal bridges - consists in the efficient insulation of the doors, the use of special materials at the contact of the foundation with the ground, at the connection between the walls, at the floors and in the roof area;
● Sealing the air circulation - the goal is to keep warm air from getting lost inside. A special fan is installed to help prevent heat loss. In general, a passive house is 4-5 times more airtight than an ordinary one;
● Heat recovery air ventilation (sometimes called "double air ventilation") - tightness is one of the basic characteristics of a passive house. As there is a permanent need for fresh air, use HRV (heat recovery ventilation). Such a system allows air to circulate and at the same time heats / cools it (as needed), using 95% heat or coolness (taken from the toilet, closet, etc.) inside. If necessary, such a system can also be used to heat water. For a house of about 120 square meters, the system costs between 800 and 1500 euros;
● Correct positioning relative to the cardinal points - this requirement can be omitted by many people, but can help reduce heat costs. The roof of the house must be arranged in such a way as to allow the sun's rays to penetrate in winter and to provide shade in summer. The thermal house should be oriented correctly towards the sun. Solar energy is captured, in the case of passive houses, by the window system of the house. Depending on the orientation of the building, it captures 40-60% of the light, if the orientation is south, 10-15% of energy, if it is north, and just under 20%, if it is east or west. The solar energy that reaches through the windows is stored by special materials with an increased inertia. The heat accumulates in the house, and through the ventilation system, the temperature rises evenly throughout the house, but without heating. However, if you choose a south-facing direction, it is advisable to use plants or blinds during hot weather to reduce the amount of heat absorbed by the sun.
Another important aspect that you can take into account is the choice of friendly appliances with low energy consumption. For example, the most energy-efficient refrigerators consume less than 200 kWh per year. An ordinary refrigerator, on the other hand, can consume between 350 and 1,400 kWh per year.
Criteria to be met for passive houses
Passive houses are an international standard in low-energy buildings. Below are the main criteria that must be met by passive houses:
● Specific energy requirements for heating or cooling: <15 kWh / m2 per year;
● Maximum required: <10 W / m2;
● Specific primary energy requirements: <120 kWh / m2 per year;
● Leakage: n50 <0.6 h-1. This number refers to how much the volume of air in the building has changed in one hour;
● Conventional energy use: <120 KWh / m2 per year. If renewable energy is also used, the conventional energy will be: <60 kWh / m2 per year;
● During the summer months, excessive temperatures occur at most 10% of the time.
How to build a passive house
The construction of a passive house starts from the project stage. Its preparation must take into account the criteria imposed by the PH (Passivhaus) standard.
In other words, no matter what the house looks like, where the kitchen or pantry will be located, the builders must follow a number of principles. In addition, the energy balance must be carried out in a special software program for the design of passive houses, PHPP (Passivhaus Projektierungs Paket).
Unlike an ordinary house, in the case of passive housing, a specialized design team is needed for this type of project.
If properly designed and built, the installation, architecture and structure will be harmoniously combined. In general, the design time is longer. Each element will be checked for temperature variations, areas where condensation may occur will be identified and resolved.
Differences between a passive house and an eco-friendly house, a green house or a low-energy house
The passive house must meet a number of stringent requirements in terms of energy consumption for heating / cooling, the need for primary energy and the degree of tightness. Eco-friendly houses, green houses or low-energy houses, however, are somewhat more vague concepts and are not internationally certified.
The house with low energy consumption, popularly called ZEB (net zero energy building), aims to consume less energy than produced. The first house of this kind used solar energy to heat and cool the house, introduced concepts such as over-insulation and sealing. Reducing energy consumption, as close to zero as possible, is achieved by using energy resources from renewable sources, especially solar energy.
The ecological house resides both in a low energy consumption and in a clear objective: a minimal impact on the environment during its construction, use and decommissioning. During construction, natural, renewable, recyclable materials, possibly purchased locally, are mainly used to reduce the effects of transport on the environment.
The passive house can also be ecological, but for this, it is necessary to use environmentally friendly materials at the time of construction. It is estimated that the incorporation of the ecological aspect in passive houses will lead to an increase in costs of up to 300 euros per square meter.
Certification of a passive house
Passive houses are certified by the Passivhaus Institute in Darmstadt (Germany) and other globally accredited building certifiers.
The passive house standard is offered to individual homes as well as office buildings, schools, kindergartens, hospitals, supermarkets or indoor swimming pools.
In a world where resources are limited, the passive house can be a solution to enjoy comfort and at the same time reduce environmental pollution. The design of such a house is complex and requires familiar help with this concept. It is important to be aware of every step of the construction in the design phase, with the choice of materials, but also in terms of the actual construction of the house. A passive house means a concern for the environment, but also for the future.
