Passive house: definition

The passive House, at present, is not a power standard, but expresses the concept of providing high level of comfort and energy saving.

Exact definition looks as follows:» The passive house represents a building for which achievement of thermal comfort (ISO 7730) can be reached only at the expense of additional heating or after cooling of weight of fresh air which is necessary for achievement of a condition of room air of rather high quality – without necessity of an additional retsirkulyatsiya of air». This difficult functional definition which does not contain any numerical values and is valid for all climatic zones. This definition shows that the Passive house is fundamental concept, instead of a casual standard. Passive houses were not invented” by someone, the concept of the Passive House was defined in the course of improvement of construction principles for increase of energy saving and comfort of residents of such houses. The term «Passive house» most fully defines this concept. The thermal comfort is reached in the maximum degree thanks to passive actions (isolation, the rekuperatsiya is warm, application of solar energy and internal sources of heat). One of key requirements to buildings which are classified as the passive house is tightness. In the house it is necessary to apply effective system of a supply and exhaust ventilation to ensuring comfort. In the passive house this system also can be used as heating, needlessly in additional channels, the main technical interfaces, auxiliary fans etc. Energy consumption in the passive house This concept of heating automatically assumes extremely low consumption of energy. It demands more effective approach to isolation of protecting designs of a building – especially in a frigid climate to keep desirable warmly in a building, and in hot climate – to keep a building from an undesirable overheat. The power balance which will help to define isolation level, for use in this house at the set climatic conditions is for this purpose made. Passive house: definition Isolation application in Passive houses the Following example of calculation (rekuperatsiya) shows requirements of the passive house for heating realization by ventilation system: Amount of fresh air, which should arrive in the house to provide high quality of air, makes 30 m? in hour. At normal pressure and temperature 21 ° the C thermal capacity of air makes 0,33 W / (m? · · °C). The maximum temperature of heating of stitched air +50°С (it is not recommended to heat up in order to avoid dust accumulation above). From this follows: 30 m? / hour/person * 0,33 W / (m? · K) * (50-20) To = 300 W/persons

Fresh warmed-up air can provide heat of 300 W on the person. Assuming 30 m? living space on one person, the maximum loading of heating time cannot exceed at present 10 W on square meter of living space irrespective of climate. As these data belong to that day years when it is necessary to provide a building with the maximum quantity of heat (thermal loading), different levels of isolation depending on climate are necessary to passive houses: it is more than isolation in Stockholm, it is less than isolation in Rome.

This specific value for heating loading (it is measured in W do not coincide with values for energy (is measured in kilowatt-hours (kW · ч). A power threshold of 15 kW · ч/(the m? · year) for heating was defined for typical Central European climate on the basis of calculations, and also practical experience. However, this value is supposed only as an approximate reference point in construction of the passive house. It can change depending on various climatic conditions: in Stockholm this indicator can be closer to 20, and in Rome it can be up to standard 10.

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